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C-DOT DSS MAX

1. 9 2 5 Remote 11 2 6 Common Channel Signalling No 7 and 0 12 Redundafi y 12 2 8 Common Hardware Units e 12 2 9 OpUmigatloti ue rrt E tant Sa 13 Hardware Architeebutk s cose eoe Geo rei err iem reed rr e p eu phe dut 15 3 1 General uidet 16 3 2 Base Module iei betta E HERE 15 2 8 Central Module CM iiie etti ER OE RS to 22 3 4 Administrative Module AM cree tt EE REPRE 26 3 5 Input Output Module nts an eaae eon Re san sae nte eso ene xvn ccce 26 3 7 Remote Switching Unit RSU e I LR V radi 31 3 8 Alarm Display iere E e EE 31 3 9 System Packagitig siehe ay ROUTER ENSURE ERAI 31 3 10 Numbering Scheme notre ihi atte decas 42 3 11 Terminal Equipment Number TEN to Physical Location Translation 44 System Initialisation amp IOP Maintenance Procedure
2. LOTS AWIL 9 YATIOYULNOO HOLIMS 45 955 ji 255 HOLIMS 3OVdS SS AHOIN IN YAXATdILINNAGYAXAIdILINN 4 AINGOW Wg L L sna gt sna q 8 51219 na sna peng i gt 81215 gsna 44 72 62 3 51215 in HOLIMS 5 45 rm Sols 4 7 Eng 51219 5 s M i gt 1219 sna 7 51802 25 MAINTENANCE PROCEDURES Chapter 3 3 3 2 3 4 3 5 3 5 1 26 Central Message Switch CMS Central Message Switch CMS complex is the central message transfer point of the switch It is implemented as four different message switches working in load sharing mode Each message switch is a high performance message routing block implemented by using high speed 32 bit microprocessor MC 68040 in case of CM XL and 16 bit microprocessor MC 68000 in case of CM L This card supports 38 HDLC links in case of CM XL with flexibility of programming individual HDLC links upto 750 kbps All Central Message Switches CMS1 2 3 amp 4 are used for routing of messages across the Base Modules On the other hand only CMS1 and CMS2 interface with the Administrative Module for routing control message between Base Processors an
3. 48 LS MICI 48 4 2 Levels of Initialisation for System Modules essen 48 4 9 Boot Up Shutdown Procedure irt tete FS 50 4 4 Procedure to Bring IOP Inservice from OOS 54 Chapter 5 Chapter 6 Chapter 7 Chapter 8 Routine MaointeriatiGG occorre NEP REX FERE EY bance 62 DU rd m m MIDI M IMEEM n 62 5 2 ot Maintenance Personnel oett Geb 62 5 3 Routine Maintenance of Base Module BM sess 65 5 4 Routine Maintenance of Central Module CM and Administrative Module AM 75 5 5 Routine Maintenance of Power Supply 76 5 8 Periodic Audits HE GEH REESE 76 5 5 Routine Mauitenance of IDs seis ehe nete eas m dU Pr ee 76 5 8 Routine Maintenance of Power 76 Maintenance of Switch Units eiit HERE EE 77 6 1 General EE 77 6 2 Trouble EIXIDg isis terns eo nec bn nets bx bend kc xus Fees be ene da Eva boues es 6 3 General 81 6 4 Procedure for Handling Alarms ss oe eerte Prov eee e
4. 2 ALINVA SI 0 21 SO INL ALINY SI quvoa H3HLON JHL 40 NI 0 ZLIL dO QuVO INL OL GALOANNOO 318 NOILVHIN3ONOO dassvd SOLLSONSVIG ALINVA SI 0 LELL NI QHVO ON dassvd gt ALINVA SI 0 01 INL e SI 0 F FIL 40 1 dO ONILLAS SI O LLLL 40 OIL 2 510 111 dO INL SI YSHLOW JHL 40 3NV Id MOVE JHL NI 0 LLLL HO QHVO INL Ol Q3193NNOO NOILVHLNSONOO ALINY 510 011 JO INL 29 SI 0 LLLL 0 0LLL N33ML38 Q3193NNOO 318V9 NOLLVHIN3ONOO ALINVA SI O F HLL 40 INL NI GYvO INL 110 Mowe MAINTENANCE PROCEDURES Chapter 6 6 4 1 2 6 4 1 2 1 94 ii If the problem persists make the standby copy of TS SCIC BMS out of service operator one by one and perform diagnostics After diagnosing the unit bring it back in service if diagnostics pass If diagnostics on any of these units fail refer to the section on TS SCIC BMS faults iii If diagnostics pass try changing the TSI card b CASE ALARM RAISED FOR MORE THAN ONE TIC IN DIFFERENT PLANES IN A CHAIN In this case even though the procedure is similar to the above case the problem needs urgent
5. wa SANIT X8Vd SANITENS A99 IN8S Chapter 2 C DOT 055 10 2 5 THE C DOT DSS FAMILY Administrative Module AM performs system level resource allocation and processing function on a centralised basis It performs all the memory and time intensive call processing support functions and also administration and maintenance functions It communicates with the Base Module via the Central Module It supports the Input Output Module for providing man machine interface It also supports the Alarm Display Panel for the audio visual indication of faults in the system Input Output Module IOM is a powerful duplex computer system that interfaces various secondary storage devices like disk drives cartridge tape drive and floppy drive It supports printers and upto 8 serial ports for video display units which are used for man machine communication interface All the bulk data processing and storage is done in this module Thus a C DOT DSS exchange depending upon its size and application consists of Base Modules maximum 32 Central Module Administrative Module Input Output Module and Alarm Display Panel The Base Modules can be remotely located or co located depending on the requirement REMOTE SWITCH UNIT Remote Switch Unit RSU is an integral part of C DOT DSS architecture In order to realise a RSU the normal BM can be modified for remoting with the host exchange
6. CHECK BACK PLANE DIAGNOSE CURRENTLY ACTIVE COPY OF JUST INTERCHANGED UNIT FIG 6 1 FLOWCHART FOR URGENT NON URGENT SWITCH UNIT FAULTS Le DOES P Pd piacnosis gt n PASSED yes hio t MOMENTARY N HARDWARE PROBLEM Contd DESIGN DSSMAX MAX XL MAX XLMP MXLMPUF1 MAINTENANCE PROCEDURES 85 Chapter 6 ix If diagnosis passes on all the units then repair is successful Make the unit inservice through PUT SWU INS command Bring the replaced unit INS ACT and make a few calls x If the diagnosis failed again in step vii then repeat step vi on card having next highest fault probability If again the problem persists go for the next card and so on xi If even after changing all the suspected cards the fault persists then check the backplane The common kinds of faults in the back plane are Bent connector pins on the front side or the pins on the back side shorting with one another Connector pulled out not making a proper connection Rupture of wire insulation leading to short between wires connector pins If the fault is identified in the backplane replace the original cards and repeat step viii The above mentioned steps should be strictly followed for handling switch unit faults unless mentioned otherwise Henceforth only the additional steps helpful in the particular case being discussed will be listed
7. 1 Replace the TSM card of the OOS SYS TS and diagnose On passing interchange and make the TS INS ACT Observe the service for some time ii If TS diagnosis fails in the above step restore the original TSM card Make the SCIC which is active OOS OPR and diagnose it If diagnosis fails replace by a healthy card Diagnose again both SCIC and TS and on passing bring them in service Make them INS ACT and observe the service for some time If SCIC is made OOS SYS refer to section 6 4 1 3 CASE BMS TSC DIRECT LINK TEST FAILED 1 ii If replacing TSC card does not rectify the fault replacing the TSS ETS in case of RBM and TSM cards in the mentioned order can be tried before replacing BMS controller card If step i fails restore the original TS complex cards Make the BMS OOS OPR and diagnose it If it fails follow section on BMS faults Otherwise replace the BMS controller card Diagnose both BMS and TS and on passing bring them in service Make them INS ACT and observe the service for some time Alarm Raised for SCIC CASE FAULT PROB ONLY FOR SCIC CARD a i CASE a FAILED TO CONTACT SCIC Refer to the general procedure given in sec 6 4 1 SCIC TSC LINK TEST FAILED FAULT PROB FOR SCIC CARD TSM CARD i If even after replacing the SCIC card diagnostics fail then make the standby TS OOS OPR and diagnose it C DOT DSS MAX MAINTENANCE OF SWITCH UNITS ii If diagnosti
8. ALARMONOOD INDICATES SWITCH YES a e ALARM CHECK DIAGNOSTIC FAILURE REPORT ON PRINTER OOD FOR SWITCH UNIT ID S DIAGNOSE THE UNITS AFTER PUTTING THEM IN OOS OPR STATE N lic M CARD PASSED DIAGNOSTICS L ee as DOES HAVE CONTROLLER Be E ue REFER FAULT SECTION FIG 6 1 DESIGN DSSMAX MAX XL MAX XLMP MXLMPUF 84 C DOT DSS MAX MAINTENANCE OF SWITCH UNITS PROBLEM Contd A OUT JACK IN ALL CARDS ASSOCIATED IN THE UNIT AND RUN DIAGNOSIS ON THEM MOMENTARY wes Um jS DIAGNOSIS 7 PASSED REPLACE THE CARD WITH HIGHEST FAULT PROBABILITY BY A GOOD CARD x ee DIAGNOSIS YES PASSES 7 Y SUCCESSFULL RUN INSERVICE PUT SWU INS YES 22 ASSOCIATED WITH REPLACED UNIT IN INS ACT STATE MAKE SOME CALLS RUN DIAGNOSIS ON THE SWITCH UNIT 2777 DIAGNOSIS esr PASSED yo 16 c CARD NO Y vis REPLACE THE CARD INTCHG HIGHER LEVEL WITH NEXT HIGHER UNIT AND RUN DIAGNOSIS FAULT PROBABILITY ON THE UNIT CARD NO 6 C PASSED
9. DESIGN DSSMAX MAX XL MAX XLMP MXLMPTSC MAINTENANCE PROCEDURES 33 Chapter 3 123 4 5 6 7 8 9 1011 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 EF Selec U Beet res U S NOTE 1 TC MAY BE LCC COM TWT OR E amp M 2 IN CASE OF TU4 AS ATU IN BM SLOT 24 WILL BE TTC IN CASE OF TUI AS ATU IN BM SLOT3 WILL BE ANNC FIG 3 9 3 ANALOG TERMINAL UNIT ATU CONFIGURATION 12 34 5 6 7 8 9 1011 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 P D D D T TIE D D D D P S T T T UJU T T T T5 U S C S 5 5 1 1 2 2 3 3 DIGITAL TERMINAL UNIT DTU CONFIGURATION DESIGN DSSMAX MAX XL MAX MP2 MP2 DTC 34 C DOT DSS MAX HARDWARE ARCHITECTURE 5 6 7 8 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 P 5 5 yr pe pe U U 112 34 5 617 C9 10 1312 13 14 15 16 1 2 1 LC PRL CARD
10. Note When CM is initialised NSC comes up in 2 hrs after warm up as level 2 oscillator is used However the status of NSC becomes inservice immediately but during warm up period proper operation is not guranteed 8 8 ALARM STRATEGY FOR NSC Following section gives the alarm strategy use for displaying NSC alarms in various conditons 1 If not all clock sources but at least one clock source of an NSC copy is out of service a non urgent alarm is raised for this NSC 2 If all the clock sources of an NSC copy are out of service then an URGENT ALARM is raised for this NSC copy 3 If all the clock sources of both the NSC copies are OOS an URGENT ALARM is raised for both the NSC copies individually under clocksource alarm It may be noted that INS COLD and UNEQUIPPED status are not not considered for calculating the alarm level This implies that for the active NSC if all the four equipped network clock sources are out of service an urgent alarm will be raised even if he dup clock is marked INS COLD Separate alarms for any of individual clock sources of NSC are raised under CLKSOURCE ALARMS The NSC switch alarm will be raised separately On the ADP NSC CLOCKSOURCE ALARM is reflected on SYSTEM CLOCK LED SAMPLE REPORT ON OOD FOR NSC CLOCKSOURCE ALARM 144 C DOT DSS MAX MAINTENANCE PROCEDURE FOR NETWORK SYNCHRONIZATION SWITCH ALARM CATEGORY RAISE CLASS URGENT ALM SEQ NO 8273 MOD NO CM UNIT ID CLK 0 The status chang
11. The test set 607 is used to test the exchange side i e LT and test set 608 is used to verify the customer end up to S Interface The test set 609 is used to evaluate the characteristics of cable pair The parameters are measured and absolute values are displayed The test is executed subject to the condition that the TTC Card is INS The test set 610 is comprehensive complete test combining tests from 607 to 609 MAINTENANCE PROCEDURES 69 Chapter 5 5 3 2 5 1 5 3 2 5 2 70 For PRI CARD only test sets 607 amp 610 are valid HOW TO OBSERVE THE STATUS OF DIGITAL LINE ISDN INTERFACE DISPL TRM STATUS to monitor the status of interface STAT TRM TML TYP TEN DIRNO On execution of the above command the current status of the U Interface is displayed which may 005 50 Fault may be in LT DLL or NT OOS SE Fault is confirmed in LT INS FREE or The interface is activated up to NT and free to provide service INSF FREE CP BUSY 5 The interface is busy and providing service ACTIVATION DEACTIVATION FROM LT It is possible to activate or deactivate the interface from the exchange side FRC TRM OOS to deactivate the interface from LT TML TYP TEN DIRNO The command can be executed after defining the parameter values The successful execution of the command confirms that the interface has been deactivated FRC TRM INS to activate the interface from LT without tests TML TYP TEN
12. 200 20000 20000 20000 5 200 o 2000 20000 20000 6 200 00 20000 20000 MAINTENANCE PROCEDURES 181 Appendix D Category farade Amps ohms LOW LOW Low 2400 3200 3200 3600 15 1000 240 Note If external voltage on the line is more than 5 99 volts no other tests will be conducted Limits for Dial Tests 5th closing high 60 msec 5th closing low 16 msec 5th opening high 100 msec 5th opening low 42 msec Dial Ratio high 4 Dial Ratio low 1 Dial Speed high IZ IPS Dial Speed low 8 IPS 182 C DOT DSS MAX Appendix E Switch Units Required for Diagnostics of an Unit Unit to be diagnosed Switch units required for diagnosis TIC with mate active units in TSU in duplex TIC with mate faulty At least one copy of all units in TSU active SCIC Duplex BMS TSC BMS and SCIC in duplex Duplex TOGC BMS SCIC TSC in duplex Simplex TOGC At least one unit of BMS SCIC and TSC active MFC At least one copy of all units in TSU active At least one copy of TIC in concerned TU ANN At least one copy of TIC in concerned TU SWC SS Standby SSC MU in BP AP SSC Standby BP AP SSC respectively MAINTENANCE PROCEDURES 183 System 4r Practices COMMENTS C DOT The following comments pertain to DowmentName ospseetion IL JL JLJLI No Month Year COMMENTS Use a separa
13. 6 4 1 2 3 96 Switching logic Present in TSS ETS in case of RBM card Control signals to TSS TSM Hence any one of the cards could be contributing to the diagnostic failure Action Change TSS card ETS Card in case of RBM or Change TSC card or Change TSM card in same order of priority Follow the general procedure except that while replacing the cards first TSS ETS in case of RBM card should be changed If that fails to solve the problem then TSC and finally TSM can be changed in that order Reset the TSC after replacing any of the cards If diagnostics fails randomly then it is likely that there is some noise in the system or the space switch clock selected by the TSC is bad In such a case more observations are required so as to give the exact nature of the fault to the repair center However the above problem should get removed by changing one of these 3 cards except in the case of SSW clock bad In such a case the test is to be repeated with only clock cable in the system at any time Note This is dangerous exercise and needs to be done with caution CASE BOTH SSW CLOCK ABSENT IN SYSTEM Action Check the 2 BM CM clock cables coming from CM to the BM At the BM end the clock cable which is housed in a 7x2 connector with a single module cover should be put on the first of the four positions of TSC card B connector At the CM end the clock cable which is connectorised similarly should be put o
14. Audit Name MBM Config SBM Config fy v wma mw w fy m ____ fy v m unsmux sw py v aupmes comm 3 wmamsmms ____ fy v 3 x ju Y ponasa w fw v anonsas v fw Y v N Y ____ ww XY v v x N Nx fy s omms Y ws fw N Pw 2 2 uz Audits Description AUD OBFR HANG The ordinary buffer hanging audit goes through the list of all ordinary buffers It finds out the owner of those buffers which are busy After determining the owner of the buffer it determines if the owner exists in the system If the owner doesn t exist it de allocates the buffer C DOT DSS MAX AUDIT SETS 10 11 12 13 14 AUD MBFR HANG The hanging message buffer audit determines the owner of every buffer that is found busy in the pool of message buffers and then determines whether the owner is still present in the system It the owner is found to have been terminated it releases the buffer making
15. C DOT DSS MAX 2 4 THE C DOT DSS FAMILY tones and simultaneously performs signal filtering on four channels This approach reduces costs power dissipation and saves space on the PCBs Analog to digital conversion on the line circuits has been achieved by using a per channel coder decoder CODEC chip Customisation based on ASICS FPGAs has been used to optimize space utilisation and reduce the number of components on the line cards BASIC GROWTH BUILDING MODULES C DOT DSS MAX exchanges can be configured using four basic modules Fig 2 1 Base Module Central Module Administrative Module d Input Output Module The Base Module BM is the basic growth unit of the system It interfaces the external world to the switch The interfaces may be subscriber lines analog and digital trunks CCM and PBX lines Each Base Module can interface upto 2024 terminations The number of Base Modules directly corresponds to the exchange size It carries out majority of call processing functions and in a small exchange application it also carries out operation and maintenance functions with the help of the Input Output Module In Single Base Module SBM exchange configuration the Base Module acts as an independent switching system and provides connections to 1500 lines and 128 trunks In such a configuration the Base Module directly interfaces with the Input Output Module for bulk data storage operations and maintenance functions Clock an
16. When NSC loses the network clock to which it was locked and when no other network clocks are available NSC enters the holdover mode Note MAINTENANCE PROCEDURES 145 Chapter 8 Each mode of operation is shown in the response of DISPL CRNT CLK SRC command 146 C DOT DSS MAX 9 1 9 2 Chapter 9 Logs Maintain GENERAL All observations and maintenance actions are to be logged in a sequential manner From this log a daily report can then be prepared which provides useful information in a structured manner Daily reports help in compiling information regarding system s performance which is of interest to external agencies such as the support centre Following logs have to be maintained REGISTERS i ii iii iv History Register This register keeps track of all the TENs of the BM Each page represents a TEN against which following information is maintained Directory Number Line Type PCO Ordinary Subs or PABX Facility provided to subscriber Date of Opening Date of Closing if any Address Access Barring etc Suppose some facility of subscriber is changed then entry is made in this register with date of changing the facility Deliverable Register This register contains the details of all the changes made in the system during a patch installation The details of checksum of EPROMs changed after patch installation in TICs SCIC and other cards is entered here System Log Book
17. e g h All pending alarms Severity of the alarm which can be critical urgent or non urgent Type or category of alarm which could be due to switch fault or due to threshold crossover of faulty terminals service circuits Identity of the switch unit suspected to be faulty in case of SBM configuration Faulty trunk group numbers and total number of faulty trunks Trunk groups are divided into small medium and large depending on the trunks present in them The alarms will be raised for these trunk groups depending on the thresholds as given in the system parameters Number of faulty lines in case the number is large Alarms will be raised for units which are in OOS SUS state and for terminals in LLO OOS SE BLK CNF OOS SO status Severity of the alarm can be known from the color of the LED that glows Latest alarm attracts the attention of maintenance personnel through blinking of visual display as well as sounding of a hooter Blinking and audio indication stops as soon as the alarm is locally acknowledged by pressing a push button on the ADP ADP however continues to display the alarm condition till such time real cause is removed In case of MBM only the most severe alarm in a module will be indicated by the LED in ADP Cyclic Alarm Display on the OOD VDU Terminal a b A portion of the screen on OOD terminal is reserved for scrolling the 10 most serious alarms When a new alarm is raised it remains on the
18. e ANS 6 ann ann rzo o nozebsi oz 1599 1299 anz 5 zoo Ona ALL 9 0 090 LOS gt gt ann ann ansS5uns OS a T 5 ann ann 5 25 UE E xxu t ons 5 wos ans 5 5 oox Oma T e gt uy A a cm and and N TS and and and and and T m m m lt lt m lt m T T i now e prp UNUSED PSM CARD SLOT SHOULD BE EQUIPPED WITH THE DUMMY LOAD CARD CML S00 UNUSED PSS CARD SLOT SHOULD BE EQUIPPED WITH THE DUMMY LOAD CARD CSL S00 HPC CAN BE USED IN PLACE OF BPC TO SUPPORT 800K BHCA NOTE FIG 3 9 14 CENTRAL MODULE XL CONFIGURATION DESIGN DSSMAX MAX XL MAX MP2 MP2 CMX 41 MAINTENANCE PROCEDURES Chapter 3 3 10 NUMBERING SCHEME In C DOT DSS MAX a common numbering scheme is employed for addressing functional modules racks within a functional module frames within a rack and card slots within a frame The system consists of four types of modules viz Base Module BM Central Module CM Administrative Module AM and Input Output Module IOM The number of Base Modules in DSS MAX can vary from 1 to 32 In case of SBM exchange only one BM i e BM 1 is needed As shown in the Fig 3 9 15 i
19. the units of one plane of TSU for which the PSU is faulty will be marked OOS SUS the units in other plane of TSU should be active iii Check the LEDs on the suspected PSU One or more of the LEDs would be off under fault conditions iv Power off and on or jack out and jack in back the same card Check whether the PSU alarm gets removed v If the fault got repaired then log it as a transient hardware problem and keep the card under observation vi Otherwise replace the PSU card Check whether PSU error LED goes off and the alarm on ADP OOD and alarm list gets removed vii If the alarm is removed then check the status of all the units in that plane of TSU All the OOS SUS units should get diagnosed and automatically brought into service If some unit fails to come in service then give reset and bring it in service If it fails then refer section switch faults viii Even after replacing the PSU if the fault persists then check the backplane The common kinds of faults in the back plane are bent connector pins on the front side or the pins on the back side shorting with one another a connector coming out wire rupturing and shorting with the pins etc If the fault gets identified on the backplane restore back the original cards Note Note given in 6 4 3 1 is applicable here also Urgent Power Supply Alarm for BPU Follow the procedure given in 6 4 3 2 and read BPU and BP in place of TSU amp BMS respectively
20. DIRNO The command can be executed after defining the parameter values The successful execution of the command will result in activation attempt being C DOT DSS MAX 5 8 2 5 3 ROUTINE MAINTENANCE initiated from the LT However in case of fault in LT or NT the interface will be deactivated with its status marked as OOS SO PUT TRM INS to activate the interface from LT after successful testing TML TYP TEN DIRNO The command can be executed after defining the parameter values subject to the condition that the TLC is already created The successful execution of the command confirms that there is no fault in LT The line status is marked as INS FREE In case of fault in DLL Digital Line loop or NT the interface will be deactivated with its status marked as OOS SO General Guidelines for O amp M Personnel On receipt of complaint from the user related to non availability of service the following sequence of operations are desired 1 Verify the status of the interface using command DISPL TRM STATUS Its status may be OOS SO indicating that the fault may be in LT DLL or NT In such cases the interface is tested using command TST TRM command It the test set 607 fails the fault is confirmed to LT In such cases any of the two options as Changing the Card or Shifting the port to another free TEN may be used as it is being followed for PSTN interface 2 It the interface status is INS FREE
21. If a process is not supposed to be present in the system involved 18 AUD HANG This audit involves determining whether a call processing dynamic process has the right to exist in the system It is different from AUD COUP in the sense that the only thing it takes into account is the time since the process has been last scheduled for if it hasn t been scheduled than the time interval since the time of it s creation If this period happens to be greater than the allowed period the process is deleted However it is ensured that the process is not in the SLEEP state in which case the process is allowed to exist for an indefinite period of time The audit also tries in release the resources that were allocated by the process which is deleted 168 C DOT DSS MAX 19 20 21 28 24 25 AUDIT SETS AUD TIC SWOVR At the time of TIC switch over quite a few discrepancies relating to the status of the terminal and the phase of the call are expected This audit tries to remove these discrepancies These discrepancies arise because the two TICs run a synchronously As a result of this during TIC switch over there is a possibility of some events messages being missed or duplicated which might lead to a mismatch in the status of a terminal as perceived by TIC vis a vis that maintained in reference memory It is the endeavour of this audit to correct some discrepancies This audit corrects only those discrepancies which can occur as
22. If the trunks is digital go to the next section 7 1 2 2 3 STATUS OF DTK BECOMING OOS SO TRANS STATUS OF TRUNKS BECOMING OOS TRANS i Perform TST TRML CARD test set 403 and proceed as in Digital Trunk Routining Failed STATUS OF TRUNKS BECOMING BLK CNF Line Routining Failed Report Analog Digital Lines This report is generated when periodic calendar based routining of lines fail Depending upon the test that was being conducted the fault can be on exchange side test sets 103 104 or 105 or outside plant test set 102 Similar tests can be done for digital line ISDN lines with the help of TST set 607 for Exchange side amp 608 for outside plant test EXCHANGE SIDE ROUTINING FAILED REPORT FOR LINES i This report is displayed when exchange side signalling or voice path tests has failed The Test set no will be 103 104 or 105 for Analog Line amp 607 for digital line ii Check whether this report has come for only this line or it has come for a large no of lines in the BM If large number of lines have gone faulty then perform the same test on some of the lines to confirm the fault If the fault persists then follow the same procedure as given in section 7 1 1 2 1 or 7 1 1 2 2 11 iv If the fault is not large numbers of lines then repeat test that has failed on the line and confirm the fault From the test number find out the nature of the fault eg ringing test failure etc Confirm the faul
23. In this log book faults description of every type is written Any activity related to exchange is to be noted down in log book MDF Log Book This important book contains the details of MDF locations for all subscriber lines outgoing and incoming trunks The register contains the following description MAINTENANCE PROCEDURES 147 Chapter 9 148 v vi vii viii Trunking diagram MAX MDF layout cable layout at line side and exchange side outgoing and incoming trunks details of different exchanges incoming junctions traffic details outgoing junctions traffic details colour coding of cables used answering circuit numbers of all the exchanges in the network Complaint Book Complaints from subscribers are noted in this register under the following headings Docket number telephone number date and time of booking fault reported action taken remarks sign date and time of clearance Directory Number Record Book This register contains the record of all subscribers under following headings Dir No subs address locations of exch TEN line side tie and pair and remarks line type whether STD is barred or not and is it a member of hunt group The directory numbers are arranged in ascending order The telephone number of complaint booking centres are also written at beginning of register Outgoing Junctions Complaint Register In this register faulty outgoing junctions are booked to distant ex
24. TERMINAL UNIT 4 TU 4 BASE PROCESSOR UNIT BPU TIME SWITCH UNIT FRAME 6 TSU FIG 3 9 11 BASE MODULE BM XL CONFIGURATION DESIGN DSSMAX MAX XL MAX MP2 MP2 BMC 38 C DOT DSS MAX HARDWARE ARCHITECTURE 234 567 8 9 1011 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 1 o gt gt ial 7 a lt gt LoD af e ooza 002 amp R Oo ost x ox m Yooz amp 8 5 2 TET e 60232 ub Bl oo E ong 8 oozeo jowor amp 6 nos oao ooro o Mouse gt EX 00 5 z aE NNS0O 8 6 onou rzw 00 0 00x zf 0020 el 0000 ki on de St o gt p onon 00 5 a of 2 zo gt an H 39 DESIGN DSSMAX MAX XL MAX MP2 MP2 CMC FIG 3 9 12 CENTRAL MODULE L CONFIGURATION MAINTENANCE PROCEDURES Chapter 3 BUS TERMINATION UNIT 00 SPACE SWITCH UNIT 5500 SPACE SWITCH UNIT 5501 BUS TER
25. a b c Check that the cartridge is not write protected Insert cartridge in drive iop5x find print cpio ocv gt TAPE For dumping any directory on a cartridge a b c d Check that the cartridge is not write protected Insert cartridge in drive IOP5x gt cd dir name is the required directory IOP5x gt 18 cpio gt TAPE Normally any cartridge should be kept write protected Only when you want to write onto it remove the write protection MAINTENANCE PROCEDURES 61 5 1 5 2 5 2 1 62 Chapter 5 Routine Maintenance GENERAL Initiatives to be taken by maintenance personnel in the best interest of the system s health are highlighted in this chapter However Chapter 6 and 7 should be referred to for remedial action in case of faults Routine maintenance philosophy as applicable to the system as a whole is described first What needs to be done for the maintenance of switch hardware terminal hardware PSU cards and IOPs are covered later ROLE OF MAINTENANCE PERSONNEL Keeping a watch on the system s health trouble fixing and programming periodic routining strategy in advance form the major functions to be performed by the maintenance personnel In addition to above following functions also require human attention 1 Co ordination with remote exchanges for trunk testing 2 Providing the necessary feedback to the support centre 3 Day to day logging of import
26. root account The operations like initial boot up software link loading etc could be performed only from the Console One X 25 port is implemented for 64Kbps full duplex link to communicate with Centralise Billing Telecom Management Network Centre In addition one 10 Mbps Ethernet port is also implemented in the IOP VH which has AUI or Co axial interface support at physical level to allow networking of user terminals in future A SCSI 2 controller with integrated DMA and SCSI cores is used for interfacing the disk drive and cartridge tape drive Note Presently the two ports namely X 25 and ETHERNET are not supported in current UNIX release IOP VH Peripherals Input Output Processor IOP VH supports three standard SCSI 2 interfaces on VHC card one each for Winchester Drive Cartridge Tape Drive and one as spare Here it may be noted that only the peripherals with SCSI 2 interface can be used in IOP VH Front Panel Display The CPU Reset and Abort switches are provided alongwith lock and key adjacent to the switches Run and Halt LEDs for the CPU status indication is also extended on the front panel A Reset LED is provided alongwith RESET switch and glows when the CPU is reseted by pressing RESET switch on the front panel Power I P LED is provided to indicate the presence of I P power on the front panel 3 6 NETWORK SYNCHRONIZATION IN C DOT DSS All the three modes of operation of Netw
27. that order Reset the TSC after replacing any of the cards d FAULT PROB FOR BOTH COPIES OF TSC 1 Assume TSC 0 is OOS SYS OOS OPR and TSC 1 is INS ACT ii If the fault persists after replacing the TSC card of the 5 0 restore the original card force it in service and make it INS ACT Ensure that the service is not affected iii Now make TSC 1 OOS OPR and replace its controller card by a healthy card Put this TS in service and make it INS ACT iv Diagnose TSC 0 again and if the diagnosis passes log TSC 1 as the faulty card Make it INS ACT and observe the service e FAULT PROB FOR TSM AND ONE OR MORE THAN ONE TIC i While following the general procedure replace TSM card first and diagnose the TS If the diagnosis passes diagnose the TIC cards and bring them in service ii Try replacing TSI card next 11 If the diagnosis fails above replace TSS ETS in case of RBM and TSC card in that order and diagnose the TS iv Replace the individual TICs one by one and repeat diagnostics CASE TSC INFORMATION MEMORY TEST FAILED Explanations In the information memory test a pattern such as 55 or AA is inserted into a time slot and a one to one or one to all switching is done and then the pattern is extracted from the corresponding time slot If the pattern matches then the test is declared passed Pattern insertion register and Pattern extraction register MAINTENANCE PROCEDURES 95 Chapter 6
28. the printer The same alarm will be available in the alarm list also CASE MF CONTROLLER GONE FAULTY a 1 ii 1 FAILED CONTACT Check the status of units in the If a MF controller is marked OOS SYS then give a reset to that MFC and try to bring it into service If MFC still fails to come inservice then jack out the MFC jack it back in give MFC a reset and try to bring it into service If the MFC comes inservice now note it as a transient hardware problem in that MFC or that card slot position Keep it under observation for a few days If MFC still fails to come inservice then replace the MFC with a new MFC card Try to bring it into service If the MFC comes inservice now then log that the old MFC had actually gone faulty Also perform a loopback test test set 301 on the MFC after bringing the MFC inservice If the test passes the repair is successful Otherwise replace with a new card MAINTENANCE PROCEDURES 117 Chapter 7 7 1 1 2 118 b vii If the new card also fails to come inservice then revert back to the old MFC card Give a command to switchover the active passive status of SCICs Try to bring the MFC into service viii If now the MFC comes into service then it is SCIC that might have gone faulty Put the standby SCIC OOS OPR and replace it with a new card Bring the SCIC into service and make it the active copy ix If now all the units
29. 7 5 8 76 ROUTINE MAINTENANCE OF POWER SUPPLY UNITS Here we shall concentrate on PSU cards installed in the switch rack i Check of all the LEDs on PSU cards once in a day ii Check whether there are any pending Power Alarms by issuing DISPL ARM LIST command If there are some attend to them first PERIODIC AUDITS 1 Most of the system integrity checks are performed by the system as idle time audits However terminal count audit Audit set 12 can be run once in every day by the operator ii Audit can be automatically run by making use of the Calendar feature Refer Appendix B and also the C DOT DSS MAX Maintenance Commands document for more information on audits ROUTINE MAINTENANCE OF IOPs This involves maintaining both the IOPs and their peripherals Back up devices such as cartridge drive require special attention as their read write heads need cleaning at regular intervals Refer to the IOP user manual for details ROUTINE MAINTENANCE OF POWER PLANT Routine maintenance of power plant is beyond the scope of this manual However it is necessary to be mentioned here that input DC supply to switch from power plant is to be monitored regularly Typical input voltage required is 50V DC C DOT DSS MAX 6 1 6 2 6 2 1 Chapter 6 Maintenance of Switch Units GENERAL This chapter offers a set of detailed procedures which guide maintenance personnel in fixing various kinds of problems occurring i
30. Administrative Module via the Input Output Module Services Announcements and conference circuits This approach is also followed while introducing new services and facilities in order to utilise them most optimally 14 C DOT DSS MAX 3 1 3 2 Chapter 3 Hardware Architecture GENERAL The hardware architecture of C DOT DSS MAX is mapped closely on the system overview described in the previous chapter In the following sections the hardware architecture of each constituent module is described BASE MODULE BM Base Module BM is the basic building block of C DOT DSS MAX It interfaces the subscribers trunks and special circuits The subscribers may be individual or grouped PBX lines analog or digital lines The trunks may be Two Wire Physical E amp M Four Wire E amp M Two Wire Digital CAS or CCS The basic functions of a Base Module are e Analog to digital conversion of all signals on analog lines and trunks e Interface to digital trunks and digital subscribers e Switching the calls between terminals connected to the same Base Module Communication with the Administrative Module via the Central Module for administrative and maintenance functions and also for majority of inter BM switching i e call processing functions e Provision of special circuits for call processing support e g digital tones announcements MF DTMF senders receivers Provision for local switching and metering in stand alone mo
31. Back at Time Switch 2 Test for All Frequencies Time Estimate 4 secs 2 Test Set 302 Loop Back Test on Receivers 1 Loop Back at Time Switch 2 Test for One Frequency 3 Test Set No 303 Loop Back Test on Tones 1 Loop Back at Time Switch 2 Test for One Tone 4 Test Set No 304 Loop Back Test on Tones 1 Loop Back at Time Switch 2 Test for All Tones D List of test sets for digital trunks TST TRML CARD 1 Test Set No 401 Tests on DTS Card Interface Signal Test TUC DTS Pattern Insertion Extraction Test TUC Front End loopback FAS Logic Test FAS Alarm Logic Test 2 Test Set No 402 Tests on DTC Card 1 2 3 Pattern Insertion Extraction Test HDB3 loopback 4 5 1 Return Direction Signalling Test 2 Go Direction Signalling Test type1 3 Go Direction Signalling Test type2 4 MFAS Logic Test 5 MFAS Alarm Logic Test 6 FIFO Test MAINTENANCE PROCEDURES 161 Appendix 162 Test Set No 403 Tests on DTS DTC Card O o N pe SU o NE de Interface Signal Test TUC DTS Pattern Insertion Extraction Test TUC Front End Loopback Pattern Insertion Extraction Test HDB3 Loopback FAS Logic Test FAS Alarm Logic Test Return Direction Signalling Test Go Direction Signalling Test 1 Go Direction Signalling Test Type2 MFAS Logic Test 10 MFAS Alarm Logic Test 11 FIFO Test Test Set No 404 Tests on DTS DTC PIE Card 1 2 Pattern Insertion
32. CBX pair The 2 048 MHz clock and 8 kHz sync signal are exchanged between the two copies of NSC Clock selection is done before the PLL block If all the inputs to the NSCs fail it runs in the holdover mode If the inputs are not restored till the end of the holdover period duration of the holdover period is defined in the Parameteric Specifications the NSCs go into the free run mode The NSCs work in mutual synchronisation as the PLLs track each other REMOTE SWITCHING UNIT RSU In case of a Remote Switch Unit RSU the Time Switch Switch TSS cards in BM are replaced by Enhanced Time Switch ETS cards This card implements different functions like HDB3 to NRZ conversion clock extraction time slot interchange on PCM links to from the host exchange digital trunk interface fault handling on digital trunks etc In case of a remotely located BM RSU the corresponding MUX DEMUX cards in BTU in CM in BUS 0 and BUS 1 are replaced by Enhanced Switch MUX ESM Cards in CM XL and ESL cards in CM L The functions of the cards are HDB3 to NRZ conversion digital trunk interface multiplexing demultiplexing of 4 Mbps bit streams from to a normal BM and a RSU The interconnections between RSU and Central Module are shown in Figure 3 8 ALARM DISPLAY PANEL Alarm Display Panel ADP is a microprocessor based hardware unit which is attached to the BP in SBM configuration or AP in MBM configuration via HDLC links for providing audio
33. In such a case the TSC sends a message towards all the 4 TICs and expects a reply In the above case 5 sent a message to all the 4 links but TU2 copy 1 TIC did not respond because either the card was not there or because the card was faulty or because the link was faulty So even if the TSC is fine in all respects because one of the TICs was faulty the diagnostics will fail Replacement of TSC card will not help Action PUT SWU OOS for TI05 1 Then give diagnosis for TSC If the test passed Put the TSC inservice the problem of 105 1 can be looked into CASE SCIC TSC LINK TEST FAILED a FAULT PROB For TSM which is made OOS SYS and SCIC which is standby i If TS is made OOS SYS replace the TSM card first Diagnose and on passing bring it in service Interchange TS and SCIC and make MAINTENANCE PROCEDURES 97 Chapter 6 6 4 1 2 7 6 4 1 3 6 4 1 3 1 6 4 1 3 2 98 b ii iii them INS ACT Observe the service for some time If diagnosis fails in the above step restore the original TSM card Make the SCIC OOS OPR and diagnose If diagnosis fails refer section on SCIC faults Otherwise try replacing SCIC by a healthy card Diagnose SCIC and TS and on passing bring them into service Interchange TS and SCIC to make them INS ACT Observe the service for some time If SCIC is made OOS SYS refer to section 6 4 1 3 FAULT PROB TSM CARD which is OOS SYS TS and SCIC which is INS ACT 1
34. LEVEL in DISPL IOP Level IOP LEVEL command This may be either active IOP or standby IOP OOS IOP Out of Service IOP No communication is possible from this with the switch 4 3 3 IOP Initialisation Levels In DSS MAX IOP may be at different levels of initialisation Depending upon the level of initialisation IOP is able to perform certain activities allowed at that level of initialisation An IOP run level is different from IOP status An IOP may be in INS ACT INS SBY but it may be running at different levels such as Inservice or Disable Update The following IOP initialisation levels are possible b c Power Off Cold Start Warm Start Disable Update All Disable Update Operator Inservice Power Off When power is switched off IOP is in Power Off level No activity is possible at this level in Cold Start This initialisation is done by just switching on power to the IOP IOP performs some diagnostics and comes to monitor prompt and waits for the user to give instructions to go to next level of initialisation At this level operator can choose to go to next level of Initialisation or can perform certain tests on IOP hardware Refer IOP user manual for details of these tests Warm Start This is the Initialisation level when the IOP is booted up by giving bo command on monitor prompt The IOP initialisation is done and DSS MAX software starts running Login prompt com
35. MBM Exchange to provide ISDN service by adding minimum additional hardware modules while retaining existing hardware units Another factor of the architecture is to support ISDN subscribers through Remote Switching Unit RSU This remote switching unit is able to provide switching facility locally even in case of failure of the communication path to the parent exchange The system employs an open ended architecture for flexibility of configuration and growth The processor architecture is characterised by distributed control and message based communication in order to achieve a loosely coupled network for a flexible system architecture Software is written in high level language C and distributed over various processors and is structured as a hierarchy of virtual machines The software is packaged such that depending upon the actual switch configuration it can be distributed over appropriate controllers The software features are implemented by communicating processes The operating system provides message communication facilities such that the processes are transparent to their physical locations For inter processor communication messages are exchanged over HDLC links that are implemented either as direct links or switched network paths This approach hides the physical details of processes from each other and provides a flexible communication network between the processors New modules can be added and existing modules can be modified without
36. Power Alarms in BTUO 1 of CM XL Power alarms in BTUs will be generated for IFC units Refer appendix C for MAX XL for Unit Ids of IFCs for which power alarm is reported The two power supplies in left side of BTU are in load sharing mode and power supplies in right side of BTU are also in load sharing mode Under any circumstances both power supplies should not be switched off in any side of BTU If power supply alarm is displayed change the corresponding power MAINTENANCE PROCEDURES 109 Chapter 6 6 4 3 5 6 4 3 6 6 4 3 7 6 4 3 8 6 4 4 6 4 4 1 110 supply and check whether power alarm gets removed In case the power alarm still persists interchange switch planes and check whether power alarm gets removed In case the power alarm gets removed make the now standby switch plane OOS replace the clock card make in service and make it INS ACT If the power alarm does not reappear mark the clock card as faulty The power supply errors for BTU and SSU are routed through the clock card Power Alarms SSUO 1 of CM XL Here the power alarms will be generated for switch cards The power supply units operation in case of CM XL is similar to that of BTUO 1 Refer appendix C b for power alarms and their corresponding unit ids for MAX XL Replace the PSU for which the alarm is generated and check If the power alarm vanishes mark the PSU as faulty Otherwise interchange switch planes and check whether power alarm gets
37. REMOTE SWITCH MUX DEMUX 551 SPACE SWITCH 9 PSS SPACE SWITCH SWITCH BM BASE MODULE CM CONTROL MODULE G BM3 BM4 THE CARDS NAME ARE APPLICABLE TO CM XL AND WILL BE DIFFERENT IN CM L WITH THE SAME FUNCTIONALITY FIGURE 3 8 INTERCONNECTION BETWEEN RSU LOCAL AND CENTRAL MODULE DESIGN DSSMAX MAX XL MAX MP2 MP2 CM CM 550 T BM2 BM 1 2 3 4 ESM1 T PSS1 PSM2 7 e A PSS1 BM3 BM4 551 BUSI ___ 68 BM2 BM 1 2 3 4 ime ESM a PSS1 PSM2 7 C1 Psst C DOT DSS MAX HARDWARE ARCHITECTURE 1 2 34 5 6 7 9 1011 1213 14 15 16 17 18 19 2021 22 23 24 25 26 P B B P S M M S U U Ovo ovr J O NOTE USED SUPPORT 800 BHCA FIG 3 9 1 BASE PROCESSOR UNIT BPU CONFIGURATION 1 2 39 4 5 6 7 8 8 10 11 12 19 14 15 16 17 18 19 20 21 22 23 24 25 26 p T MIMISIA IMIMITIT 5 5 56 575 588 8 5 8 8 8 5 U OR OR H M M S S NOTE REPLACE TSS CARDS BY ETS CARDS IN CASE OF REMOTE BASE MODULE RSU ii MSC AND MSD ARE REPLACED BY HMS FOR 800K BHCA FIG 3 9 2 TIME SWITCH UNIT TSU CONFIGURATION
38. This has been done to avoid data inconsistencies vi In case of TAX or ILT the system has to be defined for TAX functioning by setting the parameters XCHG TYPE 4 and CLI INFO 1 If it is not so the exchange will not support CLI for TAX functions in case of R2 R2 and R2 ISUP transit calls In addition to exchange configurations the incoming R2 trunk groups from parented stations should have CAMA YES with TGP TYP ORD vii For ISDN subscribers even if the subscriber has subscribed for CW facility Call Hold should also be subscribed as the facility works through HOLD and RETRIEVE messages 10 3 3 Other Precautions to be taken during Operation amp Maintenance of the Exchange i When it is required to make IOP out of service INIT IOP 2 1 should be used It is advised not to make the IOP out using command PUT FRC SWU OOS unless IOP is being synchronised ii Check the status of the system daily by using CRP command DISPL SYS ALL take corrective action for the faulty units iii Do not give TST TRM for different type of trunks amp BW at the same time in the same command iv For incoming calls Terminating as well as Transit the charge rate number should have initial charge as 0 v Take ed amp bd backups daily and tf amp bc back up by weekly vi The system parameter MIN SUBS DIALS should have value greater than or equal to the length of exchange code e g if the exchange code is 7262 the p
39. a result of TIC switch over If it finds a mismatch in the status of the terminal which can t occur as a result of tic switch over it is left to the reference memory audit to correct AUD REF MEM This audit involves validating the status of the terminal found in the Reference Memory It validates the busy status llo status and the blocked status of the terminal maintained in reference memory It ignores the login bit in the busy status which it leaves for the AUD LOGIN audit to validate AUD FRETS This audit is used for validating the status of the time slots It involves auditing a data structure of list of free time slots versus another data structure which contains the status of all the time slots Time slot here refers to intra BM time slots AUD FIX LINK This audit involves validating the linked lists of free global and local telephony resources This audit detects and corrects broken links of the doubly linked list maintained by data base After this audit has been run AUD RES COUNT should be run to correct the count of free available resources AUD RES COUNT This audit validates the count of free resources It first validates the linked list of free resources and then determines the number of free resources AUD RES STATUS This audit validates the status of the resources present in the data base data structures It should be run only after the audit AUD FIX LINK has been run and should be followed by the audit AUD RES COU
40. already dealt with in the chapter for handling alarms Diagnostics Abandoned Report This report is normally output by the system when diagnostics gets aborted in between due to some higher priority task coming up or the configuration of the system at the instance diagnostics was invoked does not permit the diagnostics on the unit specified DIAGNOSTICS ABANDONED REPORT DIAGNOSTICS NOT POSSIBLE INVALID REQUEST This report is output by the system when a diagnostics request for a unit goes typically from calendar for periodic routining when the configuration of the system at that instance does not permit the diagnostics on the unit specified Procedure i Check the status of the unit for which the diagnosing command was issued It s status should be OOS OPR If it is not put it OOS OPR and conduct diagnostics check for success Appropriately make the corrections in the calendar as it has been wrongly programmed ii If the status of the unit was OOS OPR then check the status of other units required for diagnostics Diagnostics of TIC requires that all TSU units are duplex Diagnostics of SCIC requires duplex BMS Diagnostics of MU requires duplex BP iii Check PSU which is supplying power to the unit under test DIAGNOSTICS ABANDONED REPORT DIAGNOSTICS JOB ABORTED This report is output by the system when diagnostics is going on in an unit some higher priority task arises Typically this can be spontaneous fault report
41. also provides network switched path for message communication between Base Modules between Base Module and Administrative Module and between Base Module and Central Module Base Processor Unit BPU Base Processor Unit BPU is the master controller in the Base Module It is implemented as a duplicated controller with memory units These duplicated sub units are realised in the form of the following cards Base Processor Controller BPC Card Base Memory Extender BME Card BPC controls time switching within the Base Module via the Base Message Switch and the Time Switch Controller It communicates with the Administrative Processor via Base Message Switch for operations and maintenance functions In a SBM configuration BPC directly interfaces with the Alarm Display Panel and the Input Output Module To support 8 00 000 BHCA the BPC card is replaced by High performance Processor Card HPC It is pin to pin compatible for hardware and also for software so that they are interchangeable at any site to meet specific traffic requirement Figure 3 3 summarises the various units and sub units of the Base Module CENTRAL MODULE CM Central Module CM is responsible for space switching of inter Base Module calls communication between Base Modules and the Administrative Module clock distribution and network synchronisation For these functions Central Module has a Space Switch Space Switch Controller and a Central Message Switch
42. and is able to communicate with the switch IOP Shutdown Procedure Whenever the shutdown is intentional the procedure given below should be followed Step 1 Login into admn account on the IOP which you want to make OOS Step 2 Verify that the IOP on which you are logged on is the slave IOP for example if you are on IOP 1 displ iop level If the response indicates that the IOP 1 is INS SBY then it can be put out of service and go to step 4 If the response says IOP 1 is INS ACT then go to step 3 C DOT DSS MAX 4 3 5 SYSTEM INITIALISATION amp MAINTENANCE PROCEDURE Step 3 An INS ACT IOP should not be put out of service or switched off first it has to be made INS SBY and then only it can be put out of service To change its status key in the command lt intchg mod no iom unit id iop 1 The interchange should be successful Step 4 Bring down the SBY IOP to warm level by giving the command lt init iop 2 1 Step 5 Bring this IOP to cold level by giving command lt init iop 1 1 The following message will come All the processes running in the system will now be killed and system will go to cold start level Wait for console login Now the IOP can be switched off After loading the complete software the IOP is to be shutdown The IOP in this condition is in warm level At this stage give command cd shutdown 0 Now the system will ask for Whether y
43. card as faulty Otherwise check the transmission equipment Note Wait for two minutes before making the ESM card in service after jacking it in MLF Alarm in ADP If MLF main link failure alarm LED is glowing in ADP Check whether alarm is raised for ADC in OOD and printer If alarm is present follow the procedure given in 6 4 17 Alarm raised for ADP if alarm is not present check whether dial tone is present in the system If there is no dial tone the system would have gone for some recovery stable clear etc Check whether the message for data loading patch loading or code loading is present is present on IOP console If it is present wait for some time and system will recover on its own if there is no such message and there is no dial tone in the system contact the support centre immediately Procedure for Handling Power Alarms LED flashing against the BM accompanied by an audio alarm Note that there will not be any LED flashing against any switch unit On VDU OOD power alarm would be raised and there will be print out of Power Alarm on the printer MAINTENANCE PROCEDURES 107 Chapter 6 6 4 3 1 6 4 3 2 108 Non urgent Power Supply Alarm for TU 1 ii iv The LED corresponding to the module in which power alarm is present will be blinking on ADP Check the power alarm report on OOD printer and alarm list on IOP and find out the identity of the TU in which the PSU has gone faulty an
44. exchange side functions and if it passes bring all the trunks into service ROUTINING FAILED REPORT FOR TRUNKS ANSWERING CIRCUIT TESTS i This report is displayed when answering circuit test Test set 203 fails on some outgoing trunk Answering circuit is created using the command MOD SPL NUM ii Check whether this report has come for only this trunk or it has come for a large number of trunks in the BM iii If the report has come for only this trunk then repeat this test a couple of times and confirm the fault iv If the fault is persistent then put the trunk out of service Perform the exchange side tests test set 202 to check if the fault is on the exchange side v Ifthe test fail replace the trunk card vi If the test passes then manually make a call to that trunk using the DBEN facility If the call fails check if the problem is with distant end If not inform the outside plant personnel vii If large number of trunks had gone faulty then verify the exchange side function on some of the suspected trunks If they pass then verify the sanity of the answering circuit Perform the same test on some trunks in a different trunk group viii If the tests fail there is possibility that the answering circuit might have gone faulty Test the tone generator which is currently active TST SRV TST SET 304 If the test fails replace the TOGC with a good spare and then repeat the test on the answering circuit test on t
45. fails consistently or otherwise refer the section on switch unit alarms and follow that procedure for rectifying the fault iv If the diagnostics passes consistently then interchange the active standby status of the unit immediately higher up eg for SCIC interchange BMS etc in hierarchy Repeat the diagnostics v Now if the diagnostics fails refer section on switch unit alarms vi If still the diagnostics passes then contact Control Room MAINTENANCE PROCEDURES 115 Chapter 6 6 6 2 Repeated Raising and Clearing of BPU TSU Power Alarm i Try replacing the PSU for which the alarm is raised ii If the problem continues then interchange the copies of BP using intchg command ii If now the problem gets cleared then it is the BP card which is currently standby which is faulty 6 6 3 Repeated Raising and Clearing of TU PSU Alarms i Follow 6 6 2 except that instead of BP interchange the TICs in step ii and it will be the standby TIC that is faulty in step iii 116 C DOT DSS MAX Chapter 7 Maintenance of Lines Trunks amp Service Circuits 71 THRESHOLD ALARMS amp ROUTINE MAINTENANCE COMPLAINTS 7 1 1 7 1 1 1 7 1 1 1 1 Threshold Alarms Threshold Alarm for Service Circuits MF DTMF LED flashing against service circuits accompanied by an audio alarm On VDU OOD threshold alarm would be raised and there will be print out of threshold alarm for MF SENDER MF RECEIVER or DTMF RECEIVER on
46. follow the normal procedure given for non critical faults In all the cases given below follow the general procedure given for handling switch alarm 6 4 1 1 Alarm Raised for TIC 6 4 11 1 CASE FAILED TO CONTACT TIC FAILED TO CONTACT TIC VIA ALTERNATE PATH Explanation Card is faulty TSC to TIC link faulty Note Active TSC communicates with active TIC Standby TSC communicates with standby TIC Action Change the TIC card after ensuring that it fails even after reset Interchange the TSC copy and repeat diagnostics If it passes then one of the links is bad In such a case the situation may be as follows Faulty TSMO TSIO Cable1 TUIO TIC Good TSM1 TSI1 Cable2 TUIO TIC The problem could be either in TSM or TSI or the cable It could also be in TUI or TIC because there are separate buffers for TSCO interface and interface Then the decision of changing the faulty card needs to be taken after more observations If all the TICs are failing similarly then the problem will be due to TSM or TSI In TSM card the PCM signals are checked in the TSC diagnostics In case of successfull TSC diagnostics TSI could be faulty This can happen only if the 5 2V generation on TSI card not OK Check fuse on TSI card If this is ok then the problem could be due to the corresponding PSU which is giving 9V input to TSI card through backplane In such a case the corresponding PSU is faulty and it needs to be replac
47. i Refer section 4 3 4 4 3 5 amp 4 3 6 on IOP shutdown boot up amp synchronisation procedure etc Refer to IOP VH user manual for further details Alarm Raised for TOGC CASE FAILED TO CONTACT TOGC Explanation TGA card could be faulty SCIC TGA link is faulty Action i Follow the general procedure ii If the problem continues interchange the SCICs and try to bring the TOGC inservice If now the TOGC comes inservice then it is the SCIC current standby which may be faulty Replace the SCIC and make it the active copy and check that the TOGC remains inservice iii If on the other hand even after interchanging the SCICs the TOGC does not come inservice then interchange the BMS and try bringing it inservice If it comes inservice then it may be the BMS current standby which is faulty iv Put the BMS out of service and diagnose it If diagnostics fail refer section on BMS faults Alarm Raised for TTC CASE FAILED TO CONTACT TOGC i Follow the general procedure MAINTENANCE PROCEDURES 103 Chapter 6 6 4 1 10 2 104 ii If the problem continues interchange the TICs in that TU and try to bring the TTC inservice If now the TTC comes inservice then it is the TIC current standby which may be faulty Replace the TIC and make it the active copy and check that the TTC remains inservice In exceptional cases iii If the problem is not solved then interchange SCIC and then try to bring TTC inservice
48. is going on SYNCHRONIZATION OF IOPs BEGIN STEP 0 PROCESS INIT DATA STEP 1 CURRENT DAY DUMPS STEP 2 SIF DATA STEP 3 GLOBAL DATA STEP 4 MIP DATA IOPS ARE IN DUPLEX NOW STEP 5 PAST DAY DUMPS SYNCHRONIZATION OF IOPs OVER The OOD and printer will report the completion of the above stages of synchronization When the synchronization begins the INS ACT IOP Level goes down to DIS UPD ALL No data modification activity by the operator through command or by the subscriber through feature initiation is allowed at this stage MAINTENANCE PROCEDURES 55 Chapter 4 4 4 1 1 56 When STEP 2 SIF DATA is complete the IOP LEVEL goes up to allow subscriber initiated features but operator data modification is still not allowed When 5 is completed and the OOD and Printer report TOPS ARE IN DUPLEX NOW the operator data modifications are enabled The message SYNCHRONIZATION OF IOPs OVER indicates that the entire synchronization procedure is complete and the previously OOS IOP is now In Service and Standby INS SBY Errors and Solutions If the procedure fails try steps 1 4 amp 5 again Before repeating check the HDLC links between the two IOPs and those between the OOS IOP and the AP BP for SBM If the failure persists contact the design centre with this information Both IOPs Out of Service The DSS MAX has the capability to provide service for a limited period in a sit
49. let the operator display the status of the various clock sources of both copies of NSC as well as the clock source selected by the active copy of NSC Input parameter None 142 C DOT DSS MAX MAINTENANCE PROCEDURE FOR NETWORK SYNCHRONIZATION Output The status of all the clock sources is displayed along with the clock source selected by the active NSC Sample report assuming NSC 0 as active NSC CLOCK STATUS REPORT NSC 0 CLOCK STATII DUP CLK RCLK2 RCLK1 RCLKO USRN INS 005 5 UNEQP NSC_1 CLOCK STATII DUP CLK RCLK2 RCLK1 RCLKO USRN INS COLD OOS_OPR INS 005 UNEQP SELECTED CLOCK RCLK1 Note All the existing commands e g PUT SWU INS PUT SWU OOS DGN SWU FRC SWU INS FRC SWU OOS etc will work for NSC when the unit id chosen is that of CLK 8 7 DO S AND DON TS FOR NSC CARD 1 The default status of all the three network clock sources is UNEQUIPPED 2 Since it is always the active copy that is providing clock to the system the SELECTED CLOCK shown by the DISPL CRNT CLOCK SRC command is the clock to which the ACTIVE NSC is tuned The active NSC never tunes to the DUP CLK and its is maintained as INS COLD as long as the dup clock is available to it and mate switch plane is INS 3 When no network clock is equipped the active NSC will provide self clock to the system and the standby NSC will tune to the DUP CLK The SELECTED CLOCK displayed by
50. maximum of 16 terminal unit frames including digital trunk frames can be equipped in a Base Module and the Line Modules associated with it Their unit ids vary from 01 0 1 to TI16 0 1 However only 01 0 1 05 0 1 109 0 1 amp 13 0 1 which are normally equipped in a BM are shown in the chart For concentration TICs i e 102 to 104 TIOG to 08 TI10 to TI12 and TI14 to TI16 equipped in the Line Modules information on rack no and physical frame no of any TI may be taken using displ mod info command Cards involved in these Switch Modules their card IDs and card slots in that frame are exactly same as that of any TU frame equipped in a BM 174 C DOT DSS MAX LIST OF CARD IDS IN SWITCH ALARMS amp POWER ALARMS FOR MAX XL ADMINISTRATION MODULE AM AM XL Switch unit Cards Card IDs in Physical Card Slot or Unit ID Involved Diagnosis Frame in Reports CM Cabinet ADP SMC Card not in CM of ADP cabinet lt if used CENTRAL MODULE CM CM XL ic Switch unit Cards Card IDs in Physical Card Slot or Unit id Involved Diagnosis Frame in Reports CM Cabinet mro imo CMS1 CMS2 HMS CMS3 HMS CMS4 HMS SSC 0 BPC HPC SSC 1 BPC HPC BM HM SSBID 0 CBX SSBID 1 CBX CLK 0 NSC CCK CLK 1 NSC CCK MAINTENANCE PROCEDURES 175 Appendix C Switch unit Cards Card IDs in Physi
51. removed In case the power alarm gets removed make the now standby switch plane OOS replace the clock card make in service and make it INS ACT If the power alarm does not reappear mark the clock card as faulty The power supply errors for BTU and SSU are routed through the clock card Power Alarm for SSCU in CM XL In SSCU frame two PSUs per plane one as active and the other as slave are used Replace the power supply for which the alarm is generated and check that the power alarm goes off If it does not go off check that all LEDs are glowing in the PSU and then force the corresponding SSC in service Interchange SSC and make the now standby SSC OOS Replace the BPC card make it INS and interchange If the power alarm does not reappear mark the BPC card as faulty However there won t be any alarm for slave PSU failure Refer appendix C also for MAX XL on PSU ids Power Alarm for HPU in CM XL In HPU frame both power supplies in one plane work in load sharing mode like BTUs Refer appendix C also for MAX XL for PSU ids Procedure for Handling Battery Alarm Check the power plant and verify that the battery is charged properly Procedure for Handling Overload Alarm Overload alarm and overload control report on VDU OOD and printer CPU Overload CPU overload normally occurs due to abnormally high traffic System has it s own built in mechanisms to control CPU overload and there is no need for operator to do anything other tha
52. storing appropriate commands alongwith the execution time and interval in the system s calendar through command ADD CAL Scanning Spontaneously Generated Reports All reports periodic or otherwise should be scanned daily keeping following objectives in view i To identify fresh repair needs ii To verify the repair activity done earlier is successful or not iii To verify that no of lines and trunks having Out of Service OOS status is within acceptable limits iv To detect any abnormality in system s behaviour Example Suddenly system might declare all lines faulty This could be due to a fault in the tester 1 TTC itself v To verify that no unit or link of the system remains untested or in passive service for a long duration vi To identify important observations reports which are of interest to the support centre Verifying System s Integrity It is worthwhile to keep verifying system s integrity manually from time to time This can help in uncovering those faults which might have remained undetected so far MAINTENANCE PROCEDURES 63 Chapter 5 5 2 2 5 2 3 5 2 3 1 64 Verifying sanity of TTC running audits dialling tones announcements and trunks by equipment no making a test call after TIC switchover fall into this category Trouble Fixing The need for this phase arises either on external complaints or observation of abnormal situations or when the system itself finds one or mo
53. switches or SCICs Soft Start Any exception when Operating System OS of static process is running Operator Initiated Levels of Initialisation Operator can give INIT MOD INIT SYS command to make the system go for any level of initialisation by giving a proper init option It is advised not to use INIT SYS command without consulting control rooms in DELHI or BANGALORE However INIT MOD can be used by the administrator to solve some problems 4 3 IOP BOOT UP SHUTDOWN PROCEDURE 4 3 1 4 3 2 50 Overview In a working exchange the need to shutdown and boot up IOP module may be felt due to various reasons The need may arise due to faulty behaviour of one of the IOPs or due to link problems between IOPs or IOP and AP BP It may also be intentional to make changes on only one IOP or for hardware modifications ECN or for routine maintenance of IOP This section brings out the procedure for How to put one of the IOPs out of service How to bring an out of service IOP into service Terminology Active IOP The IOP whose status is shown as INS ACT in DISPL IOP LEVEL command All communication with the switch is possible from Active IOP Standby The whose status is shown as INS SBY in DISPL IOP LEVEL command All communication between switch and standby IOP is through active IOP C DOT DSS MAX SYSTEM INITIALISATION amp MAINTENANCE PROCEDURE Inservice The IOP whose level is shown INS
54. test fails the operator will be informed through alarms and other maintenance reports Terminal Hardware Routine Maintenance For tracking the fault count for lines and trunks ADP displays the number of faulty trunks and line circuits watch should be kept on such counts on day to day basis Progress of the repair activity should be monitored and a periodic report can also be generated In case number of faulty lines or trunks happens to cause an alarm of proper intensity it should be verified and initiation of repair action ensured As part of routine maintenance procedure make at least one call via each trunk group once every 24 hours Testing of terminal H W viz lines and trunks should be scheduled after the same is over for the corresponding switch units Terminal Maintenance can be divided into five parts i e maintenance for Analog Lines Analog trunks Digital trunks PHC circuits and Digital lines ISDN MAINTENANCE PROCEDURES 67 Chapter 5 5 8 2 1 5 3 2 2 68 Procedure for Testing of Analog Lines i Each terminal circuit should get tested once in two weeks First of all the status of all the lines should be checked to see that system itself has declared any lines INS LLO or OOS SE This can be seen through DISPL TRM ALL and DISPL LSCNT OOS ii If there are already some lines OOS the operator should first test the line by TST TRM command and attend to the specified fault in the TST TRM report iii Afte
55. test passes then ask the exchange personnel at the distant end to test their outgoing end and take the necessary action Outgoing Line Report Too Many Calls Failed due to Congestion i Check the status of all the trunks in those trunk groups where excessive congestion was reported ii If most of the trunks are inservice and still there is too much congestion report then there is a possibility that some of the calls on the trunk are C DOT DSS MAX 7 1 3 4 7 1 3 5 MAINTENANCE OF LINES TRUNKS amp SERVICE CIRCUITS hanging i e the trunk circuit is marked busy although there is no call established on it Perform audit AUDIT AUD SET 20 iii If either of the audits failed then inconsistency in the status must have got cleared and problem should have got solved Too Many Lines in INS LLO Status A report is displayed on OOD if number of terminals having LLO status exceeds the threshold limit A report is also displayed if number of terminals having OOS status exceeds the limit Check whether these lines belong to the same cable In that case suspect the cable Perform TST TRM with test set 102 on few of these lines If the tests fail inform the outside plant personnel Too Many Trunks in INS LLO Status If these trunks belong to an incoming trunk group suspect the outside plant cable Perform TST TGP with test set 201 and verify that the exchange side test pass In case the concerned trunks belong to a bothway t
56. that copy will become OOS EXT This does not hold good if it is thrown out by the system i e the unit is OOS SYS For analysis purpose we are taking one chain say for example chain 3 which consists of 09 TI10 TI11 and TI12 Copy 0 of these 4 TICs will be noted as 0 chain and copy 1 of these 4 TICs will be called as copy 1 chain of TICs Now suppose a problem creeped part of 0 chain which we have to appendix As soon as problem occurred in 0 chain all the members of the TICs in copy 1 chain will be instantly changed to INS ACT status Due to the fault one or more than one TIC of the copy 0 chain will go to the OOS SUS out of service suspect status of which one or more TIC unit may go to OOS SYS status depending upon the fault Although an experienced maintenance person can locate the fault easily by elimination method but to facilitate steady and methodical approach for pinpointing the fault location following step by step approach is suggested Only one observation we have taken for reference is that due to some problem 0 chain of TICs consisting of 09 0 10 0 TI11 0 and TI12 0 are not coming in service MAINTENANCE PROCEDURES 91 O3dWTXIANdW DCXVIANTXCXVIANXVINSSQNWNDSIS3QN SI LINN 0 0LLL LINYA NI INL Q3Ssvd 0 01 AO SOIL
57. the DISPL CRNT CLK SRC command will be NO CLK SELECTED If the standby NSC loses the dup clock also it will immediately be thrown OOS Out of Service MAINTENANCE PROCEDURES 143 Chapter 8 4 When the first network clock is to be brought INS first equip that particular clock source using the command MOD CLK SRC EQPAG The status of the clock source will become OOS_OPR from UNEQUIPPED in both the NSC copies Now give SEL CLK SRC command for that clock source Both the NSC copies shall tune to this clock source In case of any failure the operator will be intimated appropriately and he can take corrective action 5 Whenever any copy of NSC is thrown OOS the status of all its clock sources which are INS will be marked OOS_SYS Also the dup clock of the MATE NSC will also be marked OOS_SYS Now when the OOS NSC is brought INS only those clock sources are considered for selection whose status is OOS_SYS OOS OPR UNEQUIPPED clock sources are not considered for selection The NSC will select the most stable in hierarchy clock available to it which will consequently be marked INS ACT Other clock sources available to the NSC will be marked INS TOBE Thus for any OOS NSC to be able to come INS it should select a clock source this clock source can be DUP clock if Active NSC is providing self clock to the system but it has to be a network clock if active NSC is tuned to a network clock source the status of which should be OOS SYS
58. the TTC which is faulty Replace it with a good spare 7 1 2 4 Trunk Routining Failed Report Analog Digital Trunk This report is generated when periodic calendar based routining of trunks fail Depending upon the test that was being conducted the fault can be exchange side test sets 201 202 or outside plant test set 203 7 1 2 4 1 EXCHANGE SIDE ROUTINING FAILED REPORT FOR TRUNKS i This report is for exchange side failure In case of digital trunks test sets 401 402 403 go to section 7 1 2 4 3 Test set 40x is used with command TST TRML CARD For analog trunk test set will be 201 or 202 with TST TRM command and the following description applies ii Check whether this report has come for only this trunk or it has come for a large number of trunks in the BM 11 If large number of trunks have gone faulty then perform the same test on some of the trunks to confirm the fault If the fault persists then follow the same procedure as given in section 7 1 1 3 iv If the fault is not reported for large number of trunks then repeat the test that has failed on that trunk and confirm the fault From the test number find out the nature of the fault eg seizure test failure etc Confirm the MAINTENANCE PROCEDURES 123 Chapter 7 7 1 2 4 2 124 fault manually if possible by using DBEN facility to dial that specific trunk v Replace the trunk card with a good spare vi Test the new trunk card for all its
59. the fault probability is on S interface The interface is tested using command TST TRM with TST SET 608 The result will indicate the test failure related to ACT DEACT of S interface CREATING A REFERENCE TEST CIRCUITS TLC IN C DOT DSS The TLC is created to simulate the functions of LT when test set 608 is executed to verify the functioning of NT up to S Interface Similarly it simulates the functions of NT to test the LT in the exchange This helps in integration of all the functional requirements of testing of ISDN Interface in C DOT 055 as the tests are simulated in conformance to actual functional requirement This avoids the use of any additional test equipment to isolate and locate the fault Sufficient checks are also incorporated to verify the sanity of TLC time to time This is possible by testing the TLC at the time of creation itself The TLC is functionally tested in totality before making it available for testing of other ISDN Interfaces in C DOT DSS MAINTENANCE PROCEDURES 71 Chapter 5 5 3 2 5 4 5 3 2 5 5 72 The TLC is created by using Command CRE TST CKT with parameters as TLC TEN TST TEN The basic requirements are 1 The TLC TEN should be the first free circuit i e not associated with DIRNO of any BRL 2 The status of the BRL card should be INS NRM This can be ensured by executing the command TST TRML CARD with test set 605 3 The TST TEN should be any free c
60. the status of the line It s status might be INS LLO Perform an outside plant test 102 on that line The insulation test will fail Inform the result of the test to the outside plant personnel Note In cae of fault in the outdoor plant the line may be INS LLO if the telephone set is not placed properly STATUS OF LINES BECOMING OOS SE FAULT IN THE EXCHANGE In this case the fault is confirmed to Exchange Side and the corrective active has to be taken as explained Trunk Status Change Report Digital Trunk STATUS OF TRUNK BECOMING OOS SE EXCHANGE FAULT For analog trunks the procedure is same as that for lines which is explained in section 7 1 2 2 1 For digital trunks perform TST TRML CARD test set number 403 and proceed as in Trunk Routining Failed section 7 1 2 4 STATUS OF TRUNK BECOMING OOS SO FAULT IN OUTSIDE PLANT i In case of Digital Trunks it can be due to absence of voltage or due to an actual ground fault First the voltage should be checked at the MDF MAINTENANCE PROCEDURES 121 Chapter 7 7 2 2 2 7 1 2 2 4 7 1 2 3 7 1 2 1 122 ii If voltage exists upto MDF and then upto connector on exchange fault should be in the trunk card The trunk card should be replaced with a good spare iii If on the other hand there is no voltage at MDF first check with the distant end If everything is proper at the distant end then cable should be faulty Inform the outside plant personnel
61. the test fails then refer chapter 6 Procedure for Testing of TOGC i For testing the active tone generator give TST SRV command with test set 304 If the test fails make the TOGC OOS OPR and refer Chapter 6 MAINTENANCE PROCEDURES 73 Chapter 5 5 3 3 3 5 3 3 4 74 If the test is successful then give INTCHG command for TOGC to make the other copy of tone generator active If the switchover is successful repeat the same test on the other copy of TOGC also Leave the TOGCs in this configuration If the switchover of Tone Generators is unsuccessful then one of the links from TOGC to SCIC must have gone faulty If after switchover one of the TOGCs is declared OOS SYS follow the procedure in chapter on Trouble Fixing Procedures If the switchover failed but no unit is declared OOS SYS then follow the procedure given in section on transient faults Procedure for Testing of ANNC There is no command based testing possible for Announcement Controller It has to be done manually From a subscriber with DBE facility Dialling By Equipment Number dial to all the announcements one after another It is recommended that at least all the announcements are checked once in a day The procedure is as follows LH DT 1683 TEN i i iii v E Confirm that announcement fed is the dialled one Disconnect Note LH DT TEN 1683 Lift Hand set Dial Tone Terminal Equipment No of the ann
62. visual indication of system faults It is a three card implementation matrix of LEDs is provided to indicate the maintenance status of the switch units and their level of initialisation A seven segment display shows the count of lines and trunks currently faulty Keys are provided for manual acknowledgment initiating self test and selective audio disable SYSTEM PACKAGING For the O amp M personnel it is very important to know the details of actual positioning of each hardware so that the spares are replaced with ease without any major or catastrophic failure This becomes more important when co existance of multiple hardware configurations is supported All the submodules packaging details are clearly explained in figures 3 9 1 to 3 9 14 Note 1 It is advised to follow the DO s and DONT s for spare cards handling specially for controller cards as explained in chapter 10 of this document Note 2 In case of any confusion refer to packaging details Fig 3 9 1 to 3 9 14 to identify the correct slot for spare replacement MAINTENANCE PROCEDURES 31 Chapter 3 32 CO LOCATED BM 2 512ts 4Mbps CABLES BUS1 15 1 51215 4Mbps REMOTE BM i 5 8 2 Pi PCM LINKS Ais BUS1 gt 1 ETS 1 8x2 Mbps RSU TS TIME SWITCH ETS ENHANCED REMOTE TIME SWITCH 9 PSM ESM SPACE SWITCH MUX DEMUX ENHANCED
63. which can be tried before suspecting the backplane if the general procedure fails PROCEDURE FOR HANDLING CRITICAL SWITCH UNIT FAULTS Refer Fig 6 2 If for some reason both copies of TS or SCIC or BMS go faulty then follow the procedure given below For such critical faults there will be a red LED on ADP flashing against the module in which both copies are faulty Also if the fault does not get rectified immediately the BM will start going for repeated boots In such conditions we will have alternately critical alarm against MLF and the faulty unit in SBM RAX In MBM exchanges alarm will be reported to corresponding module i Give reset to both copies of the faulty unit and wait ii If the fault get rectified the System will make one of the copies inservice and recover on its own ii If system fails to recover try a jack out and jack in of one copy and then the other if necessary iv If the problem continues then jack out both copies and replace all the cards of one copy with a good set of spare cards If system does not recover contact the control room 86 C DOT DSS MAX MAINTENANCE OF SWITCH UNITS REFER w CORRESPONDING SECTIONS FOR THE ALARM SHOWN FLOWCHART FOR CRITICAL SWITCH UNIT FAULTS P RED LED i AGAINST _ 2 CHECKON 7 OOD PRINTER WHETHER gt hs ITISSWTCH C ALARM 7 YES NOTE DOWN BM NO AND UNIT ID OF SWI
64. which supports a maximum of 32 Base Modules BM XL This document apprises maintenance personnel of their role in maintaining the C DOT DSS family products for different configurations of SBM and MBM Exchanges The maintenance procedure for SBM and MBM Exchanges are same except that 1 In SBM Exchanges IOPs are connected to BP in BM Rack and in MBM it is connected to AP in CM Rack ii Additional maintenance procedure of CM Rack which is used only in MBM Exchanges iii Different ADPs SBM and MBM Exchanges are connected to BP amp AP respectively Wherever the maintenance procedures differ for the specific configuration the cross reference and special instructions in the form of Note has been incorporated The organisation of the document is as follows Chapter 2 provides all the information on system description and packaging Chapter 3 explains the hardware architecture of the system Chapter 4 describes the system initialisation including software loading and IOP boot up shut down procedures Chapter 5 describes the routine maintenance philosophy for various modules Chapter 6 details preventive maintenance trouble shooting and repair aspects of maintenance MAINTENANCE PROCEDURES 5 Chapter 1 Chapter 7 describes the maintenance procedures of terminals as well as service circuits Chapter 8 describes the maintenance procedure for Network synchronization Chapter 9 gives some recommendations regarding pr
65. 1 OOS Repeat the diagnosis of IFC If it passes replace the HMS as faulty If it still fails make the other CMS in the bus OOS and repeat the above Note Check the jumper setting in the PSM card before jacking in the new card CASE FAILED TO CONTACT CMS a Fault Prob for HMS card Replace the HMS card and repeat the diagnosis If it passes mark the HMS card as faulty If it fails interchange SSC and repeat the diagnosis If it passes the link between SSC now standby and HMS may be faulty Make SBY SSC OOS and replace the BPC card make it inservice and repeat the diagnosis If the diagnosis passes now mark BPC card as faulty b Fault Probability for HMS card and some IFC cards In this case replace the HMS card and repeat the diagnosis If it passes mark the HMS card as faulty If the diagnosis still fails make the IFC for which the fault probability is shown OOS replace the PSM card put in service and repeat the CMS diagnosis If it passes mark the PSM card as faulty CASE MATE WATCHDOG TEST FAILED CMS DIAGNOSIS If this error is displayed replace the HMS card and repeat the diagnosis If the diagnosis passes mark the HMS card as faulty This test can also fail due to fault in the other CMS For isolating this the HMS of the mate CMS has to be replaced For CMS1 the mate CMS is CMS2 and vice versa Similarly for CMS3 mate CMS is CMS4 and vice versa CASE SPACE SWITCH DIAGNOSIS FAILED In this case follow t
66. 4 1 2 iv Diagnose both BMS and TS and on passing bring them in service Make them INS ACT and observe the service for some time 6 4 1 4 4 CASE BMS LINK TEST FAILED a MSC AND BP ACTIVE OR STANDBY CARD i Makethe BMS OOS OPR and diagnose ii If the diagnosis fails replace the MSC card by a healthy card Diagnose BMS again and on passing bring it in service Make it INS ACT and observe the service for some time iii If BMS diagnosis fails restore the original card Make BP OOS OPR and diagnose If BP diagnosis fails refer to section 6 4 1 5 100 C DOT DSS MAX 6 4 1 4 5 6 4 1 4 6 6 4 1 5 6 4 1 5 1 MAINTENANCE OF SWITCH UNITS iv If BP diagnosis passes in the above step replace card Diagnose both BMS and BP and on passing bring them in service Make them INS ACT and observe the service for some time CASE 32 CHANNEL PCM LOOPBACK TEST FAILED ON BMS Explanation 32 channel PCM loopback test failure indicates that whatever data sent to the 32 ADLCs 16 ADLCs in BMS mode because of one MSD card when loopbacked back in the MSD card is not being received faithfully Some of the ADLCs on MSD card could be faulty Action Change the MSD card Check if all the jumper position is with the BMS mode and not CMS mode Note There are 3 sets of jumper in the card for BMS CMS MSC card also could be faulty but less probable CASE DMA ADLC TEST FAILED ON BMS Explanation There are totally 22
67. 8 9 1011 12 13 14 15 16 17 18 19 2021 22 23 24 25 26 P P 2 9 5 5 8 U 5 LILIES ss ssis aY JU H H ile l 1 AJA 2 X x X X SSU 1 CONFIGURATION DESIGN DSSMAX MAX XL MAX MP2 MP2 SSU 36 C DOT DSS MAX HARDWARE ARCHITECTURE 12 34 5 6 7 8 9 1011 12 13 14 15 16 17 18 19 2021 22 23 24 25 26 P P HICICIHIN t 5 5 6 PIMIMIPIS 5 5 U U U 4 x x x x x x SSCU CONFIGURATION 1 2 39 4 6 6 7 8 81011 12 13 14 15 16 17 18 19 20 21 22 25 24 25 26 P GICIR 5 5 5 5 U U Bb S bh S Beh U 0 1 2 3 X x x x X ox X x X x Xx FIG 3 9 10 HPU CONFIGURATION DESIGN DSSMAX MAX XL MAX MP2 MP2 HPU MAINTENANCE PROCEDURES 37 Chapter 3 TERMINAL UNIT 1 TU 1 TERMINAL UNIT 2 TU2 TERMINAL UNIT 3 3 TUS
68. ADLCs in the MSW complex on BMS mode The 6 direct link ADLCs in MSC card while the remaining 16 PCM link ADLCs are in the MSD card Depending on which of the ADLCs the test has failed either MSC or MSD has to be changed Action Change MSC card OR Change MSD card If problem still persists check if the 2 MHz clock coming from SCIC is reaching MSD properly i e problem could be at the SCIC end Interchange SCIC and repeat diagnostics Change SCIC card if test is found to fail with only one SCIC Alarm Raised for BP CASE FAILED TO CONTACT BP If indicated the possible faults could be as listed below Card is faulty BP to BP link is not MAINTENANCE PROCEDURES 101 Chapter 6 6 4 1 5 2 6 4 1 6 6 4 1 6 1 6 4 1 7 102 Action Reset the out of service BP card and perform diagnosis If passes put the BP inservice If fails replace the BPC card Ensure correct EPROMs in the new card Follow the general procedure CASE MATE WATCHDOG TEST FAILS Explanation The possible faults could be as listed below Card watchdog output circuit may be faulty Card watchdog input circuit may be faulty Interrupt generation may be faulty Other copy BP may be faulty Action Change the BPC card If problem persists force this BPC in service FRC SWU INS Ensure that there is no other problem in this card Do an interchange of BP INTCHG Ensure that system is stable Then put th
69. B1 B1 PSS 8K 8K 8K 8K 16M 16M PSM P 16 8K 16M 8K TSC 0 1 gt Pd TIC lt gt TIC p TO CLOCK DISTRIBUTION DESIGN DSSMAX MAX XL MAX MP2 MP2 CD1 C DOT DSS MAX MAINTENANCE PROCEDURE FOR NETWORK SYNCHRONIZATION 8 1 1 position of nsc card in the system The NSC card sits in the SCU Space Switch Controller Unit frame of the CM XL cabinet It interfaces on the CPU bus of SSC Space Switch Controller and shares the bus with CBX CPU Bus Extender Card and memory card It acts as a device to the SSC 8 2 FUNCTION OF THE CARD The NSC card forms the interface between the USRN DTS Digital Trunk System and the CCKs Central Clock Cards It receives the 2 048 MHz reference input clock from either USRN or DTS and converts it into a 16 384 MHz clock using a digital PLL Phase Locked Loop and feed this clock to both copies of CCKs It also generates a sync signal 8 kHz and feeds it to the CCKs for further distribution to all the BMs There is a Time of Day TOD block which generates the real time clock for the system It takes an input from DTS cards in future a one hertz clock and embeds this in the 8 kHz sync The NSC has an On Board Micro Processor to take of the PLL functions diagnostics communication with SSC 8 3 DUPLICATION AND SECURITY BLOCK The NSC card is duplicated and its access is similar to CBX cards The NSC and CBX form a security blo
70. C DOT DSS MAX MAINTENANCE PROCEDURES System Section No 400 513 0742 1 Issue 01 April 1999 Practices C DOT DSSMAX MAINTENANCE PROCEDURES Updated w r t Software Release 2 1 1 1 1999 C DOT Printed in India C DOT DSS MAINTENANCE PROCEDURES Updated w r t Software Release 2_1 1 1 ISSUE 01 APRIL 1999 CHAITRA 2055 SERIES 500 MAINTENANCE CSP SECTION 400 513 0742 THIS C DOT SYSTEM PRACTICE REFERS TO THE C DOT DIGITAL SWITCHING SYSTEM MAIN AUTOMATIC EXCHANGE ABBREVIATED AS C DOT DSS MAX IN THE REST OF THIS PUBLICATION THE INFORMATION IN THIS SYSTEM PRACTICE IS FOR INFORMATION PURPOSES AND 15 SUBJ ECT TO CHANGE WITHOUT NOTICE A COMVENT FORM HAS BEEN INCLUDED AT THE END OF THIS PUBLICATION FOR READER S COMMENTS IF THE FORM HAS BEEN USED COMMENTS MAY BE ADDRESSED TO THE DIRECTOR SYSTEMS CENTRE FOR DEVELOPMENT OF TELEMATICS 39 MAIN PUSA ROAD NEW DELHI 110 005 1999 BY C DOT NEWDELH Chapter 1 Chapter 2 Chapter 3 Chapter 4 Table of Contents 5 5 The C DOT DSS Family ie dea esu 7 2 1 Generali ca ovens A en nan 7 22 Flexible Architecture dincasantamnedeannsanaes 7 2 9 Technology 8 2 4 Basic Growth Building
71. CM provides connectivity to 16 BMs if it is CM L and 32 BMs if it is CM XL Each BM interfaces with CM via two 512 channel parallel buses as BUS 0 and BUS 1 each operating at 4 Mbps These buses carry voice information of 512 terminations of the Base Module towards CM In the reverse direction after space switching has been done in the Space Switch under the control of Space Switch Controller SSC the same buses carry the switched voice information for 512 terminations towards BM Thus in a 32 Base Module configuration there are 64 parallel buses carrying the voice information from Base Modules to the Central Module and also the switched information in the reverse direction Space Switch SS and Space Switch Controller SSC In order to take care of the large number of interface signals the switch portion of CM is divided into three stages viz MUX stage Switch stage and C DOT DSS MAX HARDWARE ARCHITECTURE DEMUX stage The MUX and DEMUX stages are implemented on single card to provide the Base Module to Central Module interface in each direction Interfacing and switching are controlled by SSC which provides control signals for the MUX DEMUX cards and the Space Switch Switch cards Interconnection between MUX DEMUX cards and the Space Switch is shown in Figure 3 4 MUX DEMUX Cards extract the information from time slots 0 and 1 of BusO and Busl from the Base Modules These time slots carry control message from each Base Module and t
72. DSS MAX 5 9 2 3 5 3 2 4 5 9 2 5 ROUTINE MAINTENANCE Procedure for Testing of PHC Terminals i Each PHC terminal should get tested atleast once in 24 hours First of all the status of all the PHC terminals should be checked to see if any of the PHC terminal is in faulty condition This can be seen through DISPL TRM ALL amp DISPL LSCNT OOS command ii If there are some PHC terminals which are faulty the operator should first test it with the help of TST TRM command and fix the problem or replace the card The following test set can be used to test the PHC terminal with the help of TST TRM command after making it to OOS OPR status Test set no 502 To test the successful working of terminal Testing of Digital Trunk CCS or CAS Cards Testing of digital trunk cards equipped as DTK CAS DTK CCS can be done with the help of command TST TRML CARD with parameters as CARD TYPE DTK CAS DTK CCS TEST SET 401 to 406 where Test set 401 Tests on DTS card for card type as DTK CCS DTK CAS Test set 402 Tests DTC card only for DTK CAS 403 Tests on DTC DTS cards only for DTK CAS Note There is no command as TST DTK in the Software Release 2 1 1 1 Release Test Procedures for Digital Line ISDN Interface The CRP command TST TRM is used to perform the tests on the U Interface in C DOT DSS The valid value for the test sets are 607 608 609 amp 610 The details of the test sets are listed in ANNEX
73. ES If any Power Supply Unit is failed in BM LM or CM the UNIT ID for which power alarm raised is reported in OOD and printer Following chart gives power supply units and corresponding unit IDs for which power alarm is reported The UNIT ID for which power alarm raised changed will be referred here as PSU ID of the power supply unit involved in the alarm BASE MODULE BM XL OOD Printer Frame In case of Line Modules PSU IDs reported depend upon the corresponding TIC id equipped in the frame MAINTENANCE PROCEDURES 179 Appendix C CENTRAL MODULE INCLUDING AM Administrative Module OOD Printer Frame T In case of power supplies in slots 3 amp 23 slave PSU of SSCU frame no alarm will be reported 180 C DOT DSS MAX Appendix D Limits for TTC Measurements The limits of insulation resistance loop resistance and capacitance for different line categories of subscribers The line category of the subscriber has to be assigned depending on the values of insulation resistance capacitance and loop resistance These may vary depending on the instrument connected Normally category 2 can be used for DTMF instruments The limiting values for different categories are listed below Insulation Resistance Low in Insulation Resistance High in Category kohms kohms b amp and b amp gnd 20000 20000 20000 2 20 o 200 20000 20000 2000 o 20000 20000 4
74. ET NUMBER Test Set Numbers are used for performing various maintenance tests on the system Test Set Numbers determine the type of tests to be performed Test Set Numbers have been divided as follows L 2 C Test Set Numbers 100 to 199 for Lines Used in TST TRM command Test Set Numbers 200 to 299 for Trunks Used in TST TRM and TST TGP commands Test Set Numbers 300 to 399 for Service Circuits Used in TST SRV command Test Set Numbers 400 to 499 for Digital Trunks Used in TST DTK command Test Set Numbers 500 to 599 for PHC terminals Used in TST TRM command Test Set Numbers 600 to 699 for BRI PRI links Used in TST TRM command Test Set Numbers 1000 to 2000 for routining Switch Units Used in TST SWU command Not available presently Trunk Offer test for trunks and reversal check for lines is done only for terminations configured as operator trunks or CCBs or PBX with reversal facility II LIST OF TEST SETS List of test sets for Analog lines TST TRM 1 Test Set No 102 Outside Plant Open Loop Tests on Lines 1 Interference Voltage Test 2 Insulation Resistance Test 3 Capacitance Test including instrument capacitance Time Estimate 120 secs 2 Test Set No 103 Exchange Side Tests on Lines Signalling Codec MAINTENANCE PROCEDURES 157 Appendix 158 Line Circuit Current Limiting Circuitry Check test 1 Line Circuit Current Limiting Circuitry Chec
75. Extraction Test TUC Front Loopback Pattern Insertion Extraction Test HDB3 Loopback Test Set No 405 Tests on DTS DTC FAS amp MFAS 1 2 8 4 5 FAS Logic test FAS Alarm Logic test MFAS Logic Test MFAS Alarm Logic Test FIFO Test Test Set No 406 Tests on DTC Signalling Card 2 2 8 Return Direction Signalling Test Go Direction Signalling Test type1 Go Direction Signalling Test type2 C DOT DSS MAX TEST SETS E List of test set for PHC terminal SHM The following test is carried out with command TST TRM Test set 502 TEST SET 502 S No Test Name Test No 1 NDP PSU DRV 9 To check if the PSUs in the plane of the faulty unit are down If both PSUs are down diagnostics are not carried out NDP TRMLS CNTCT 11 To try and access the PHC card s shared RAM to check that the PHCis accessible NDP SANITY DRV 10 Dummy test always a SUCCESS is returned NDP POWON TRMLS 7 message is sent to to make the PHC boot NDP TRMLS CNTCT 11 The PHC is contacted again to ensure that it has successfully completed the boot up process NDP INIT ALIGN DRV 9 A loopback is created at TUC between the trml under diagnostics amp another healthy 7 terminal and then level 2 alignment is tried on the loopback If there is no free 7 terminal available or the nailup at TUC is unsuccessful the test is still considered success
76. HANGE REPORT UNIT ID NSC 1 CLOCK SOURCE RCLK2 RESULT INVALID_CHANGE NEW STATUS OOS_OPR OLD STATUS OOS_OPR 8 6 1 6 SEL CLK SRC Select Clock Source Function Through this command the operator can make both the NSC copies select a particular clock source This command is particularly useful when the first network clock source is being brought INS Input parameter 1 CLK Possible values already existing 1 NSE 0 2 NSE 1 3 TSC 0 MAINTENANCE PROCEDURES 141 Chapter 8 4 5 1 Possible values added for NSC 5 RCLKO 6 RCLK1 7 RCLK2 8 USRN 9 DUP CLK Note The clock source should not UNEQUIPPED Also the requested clock source should not be the one to which the two NSC cards are already tuned Output The result of the command is displayed as PASS if both the NSC copies could select the clock source successfully Sample report CLOCK SELECTION PASS FAIL REPORT RESULT PASS REQUESTED CLOCK RCLK2 TUNED CLOCK RCLK2 If the excution of command fails the result displayed is INVALID_CHANGE If the clock source is not available to one of the two NSC copies the same is indicated in the report In this case the TUNED CLOCK is the clock to which active NSC is tuned Sample report CLOCK SELECTION PASS FAIL REPORT RESULT FAILURE AS REQUESTED CLOCK NOT AVAIL TO REQUESTED CLOCK RCLK2 TUNED CLOCK RCLK2 8 6 1 7 DISPL CRNT CLK SRC Display Current Clock Source Function To
77. IG EVE TTE ARES 147 9 ettet tenementis taedium 147 92 ES caesis emere 147 93 mr 149 9 4 RE BOLUS REV 150 95 Manuals Required eerte tuerentur ret nno been o reta o 150 Do s and Donts or MamtenaniCe recette o closes eee pupa e ee e REEF ERE tensa 152 TO T General lt 152 Do Sand ee M EE 152 10 3 Routine Operational and Maintenance Precautions 154 ev METERS 157 Audit d AIR T 165 List of Card IDs in Switch Alarms amp Power Alarms for 172 Limits for TTC Measurements tete Ia HE e salen 181 Switch Units Required for Diagnostics of an 183 H HOME MAX2111 WORD MXMNTPRO DOC April 15 1999 Chapter 1 Introduction 11 GENERAL In C DOT DSS two types of configurations are envisaged at Central Module level depending on the number of Base Modules connected to it The first one is MAX L Main Automatic Exchange Large which supports a maximum of 16 Base Modules BM and the other is MAX XL Main Automatic Exchange Extra Large
78. If it comes in service then it is the standby SCIC which is faulty iv If on the other hand even after interchanging the TICs TTC does not come inservice then interchange the BMS and try bringing it inservice If it comes inservice then it may be the BMS current standby which is faulty v Put the BMS out of service and diagnose it If diagnostics fail refer section on BMS faults CASE HEALTH LOG NOT PROPER i Check the fuses in TTC card if they are intact go to step ii If not replace the blown fuse jack in the card and put in service use fuses of correct rating 100 mA ii Replace the card with a good spare card and diagnose If the diagnosis passes mark the original card as faulty and put the new card in service If the diagnosis still fails restore the original card and go to next step ii This error can also be due to one of the Test Access TA relay getting stuck in one of the TUs First the TU in which the relay is stuck is to be identified Remove the TA bus cable from the back plane connector of 4th TU 3rd and 4th blocks in B connector of 2nd slot Perform the diagnosis if the diagnosis passes the problem is not present in 4th TU If it is failed the problem may be identified in 4th TU and go to step v iv To isolate other TUs put back the TA bus cable of only main TU of 3rd TU and repeat the diagnosis If it fails the problem is present in that TU Repeat the procedure with all other frames til
79. L ANIT WOd 51 SUNN IWNINYAL SANIT Sdqw 8 51 821 YNO C DOT 055 20 HARDWARE ARCHITECTURE Service Unit SU Service Unit is integrated around three different cards as Tone Generator with Answering Circuit TGA Service Circuit Interface Controller SCIC and MF DTMF Controller MFC Card MF DTMF circuits senders receivers are implemented by using single chip 4 channel Digital Signal Processors DSPs Two MFC cards are grouped to form a terminal group Upto four Cards can be equipped The TGA and two groups of MFCs form three terminal groups towards the Service Circuits Interface SCI Service Circuit Interface multiplexes these three TGs together with another terminal group from the Base Message Switch BMS to form a 128 channel 8Mbps link under the control of Service Circuits Interface Controller SCIC and sends it towards the Time Switch Base Message Switch BMS Base Message Switch BMS routes the control messages within the Base Module across different Base Modules and also Administrative Module via the Central Module It is implemented around two different cards as Message Switch Controller MSC with six direct HDLC links and the Message Switch Device MSD Card implementing 16 switched HDLC links As a unit total 22 HDLC channels are implemented for communication with the Base Processor Time Switch Controller Servi
80. MINATION UNIT BTU1 SPACE SWITCH CONTROLLER UNIT SSCU HIGH POWER ADMINISTRATIVE PROCESSOR UNIT HPU FIG 3 9 13 CM XL CONFIGURATION DESIGN DSSMAX MAX XL MAX MP2 MP2 CM1 FRAME 1 FRAME 2 FRAME 3 FRAME 4 FRAME 5 FRAME 6 40 C DOT DSS MAX HARDWARE ARCHITECTURE Dao 8 S gt 3 5 gt o o a m m lt N 4 0 an d on gt an lt an d N an d 0 2 i 5 ann 5 UG 925 0 0 ane 5 2 osu 1 T NMS ly ann oZ lt rzo ans 5 2 5 om x 5 ann ans 5 5 5 5 ann ann ans 5 5 rzo ans 5 UNS ann ans5 gt zoo m zu M 5 ann ans 5 5 mao 1 Osa Osa QUE lt 00 OZ 1 m Om ipeo OB lt 00 Om 1 lt 8 1 lt o 0 5 ann gt gt rao moo 010 5 ann ann gt
81. NH3Hl3 ASIA A A 4 SH 8 ALANYSHLA ISOS 39018 5 Ola d8 dV JALOV OL 401 d8 dV JALOV OL 30 A8QNVIS A8S SNI WOHdHlVd NOILVOINQIWAOO LOV SNI 0 401 LOV SNI O dg dv A8S SNI C DOT DSS MAX 28 HARDWARE ARCHITECTURE active processes reside in the dynamic RAM Also the data being transferred through HDLC links secondary storage devices and terminals use the dynamic RAM The IOP as a module is duplicated to provide rendundancy for cardridge and disk drives as well as serial communication terminals and printers The system has provision for 7 HDLC channels Two of these are used to connect the IOP to both the copies of AP BP The third link is for connection with mate IOP when the two are working in synchronisation i e duplex IOP configuration The rest four links are spare at present but may be used towards the four CMSs in future Eight of RS 232C Serial Links through ASIO ports are also implemented for connecting operator terminals and printer to the IOP in addition to two ports as Console and Host The monitor based operations are performed only from the Console and the same is true in case of login to
82. NT MAINTENANCE PROCEDURES 169 Appendix B 26 AUD LOGIN The login audit validates the status of the login bit in the terminal status field of reference memory The audit determines whether the terminal whose login status is being audited is an operator line If it is not an operator line it checks that the login bit of the status field for that terminal should not be set If it is set it resets it If it is an operator line it interacts with ORP and uses the data base to determine whether it is free busy in the resource list to audit the login status of the operator line 27 AUD OVL The audit on overload checks and corrects the consistency of the internal data structures of OCP and ensures that the control actions taken by OCP are appropriate Particularly the possibility of the system remaining under overload control without ant actual overload is eliminate Check consistency of the scheduler in overload state OCP should have a timer running and the task wise data should be consistent Any discrepancy is non recoverable and hence OCP is rolled back From scheduler data the control level table is reconstructed and checked against the one maintained by OCP If inconsistent the OCP table is corrected The current control actions are corrected by mailing new messages to TICs and SCP 34 AUD ADP ALM Alarm audit audits the list of switch alarms power alarms and module alarms against the actual status and corrects
83. ORD 10 2 3 Calender Programming in C DOT DSS To maintain consistency of alarms and reports for lines trunks and service circuits AUDIT with AUDIT SET 12 should be programmed in the calender with daily triggers for all the days in the current year This programming is required to be done only once in a year every time a software is loaded in the exchange 10 2 4 Use of TSC PROM s in Different Exchange Configurations When BMs of MAX L are being integrated with MAX XL or BM XL are being integrated with MAX L then following care should be taken for use of TSC PROM The checksum for TSC PROM will be same for BM L as well as for BM XL if used as SBM RAX or as colocated BM RSU of MAX L The checksum for TSC PROM will be same for BM L as well as for BM XL if used as colocated BM or RSU of MAX XL Precisely we can conclude from the above that the PROMs on TSC will depend on the type of CM i e CM L or CM XL and it is independent of BM type 10 2 5 TIC Cards with Compatible Software EPROMs The C DOT DSS supports distinctive ringing in all the new exchanges with retrofit option for existing sites The software has been designed to take care of compatibility related problems The exchange is defined to support Distinctive Ringing by setting the system parameter SPL RNG to 1 At these sites all the PSUs should be updated for ECNs Also the TIC cards should be updated for compatible software EPROM The TIC unit will not beco
84. OS OPR and left in that state c Manually resetting a microprocessor based controller d Tracing and repairing a faulty cable in the external plant e Initializing the system partially or fully f Taking help of the support centre 6 3 GENERAL FAULTS There are broadly two kinds of faults in the system MAINTENANCE PROCEDURES 81 Chapter 6 6 4 6 4 1 82 Type 1 Faults as indicated by the diagnostics or routining through commands e g DGN SWU TST TRM TST SRV TST TRML CARD PUT SWU INS Type 2 Spontaneous faults in the system which may or may not be recreatable As a result of these faults the particular unit may go OOS SUS OOS SYS INS ACT or INS SBY If it goes OOS SYS then the diagnostics of the particular switch unit may pass or fail If it fails then the problem is of type 1 If it passes and the problem is not isolatable by diagnostics but appears spontaneously then the problem is of type 2 In case of system detected faults information which is of interest to maintenance personnel for trouble fixing purposes can be extracted from the alarms and associated reports The information helps in following 1 locating the suspected unit li knowing urgency of repair or corrective action iii knowing type of corrective action required iv nature of fault detected by the system v identities of the card cards suspected to be faulty PROCEDURE FOR HANDLING ALARMS Any fault in the system which is af
85. P Depending on the number of trunks faulty in the trunk group the alarm will be Non urgent Urgent or Critical The threshold values for small medium and large trunk groups can be seen from the system parameters The same alarm would be available on VDU OOD and printer also C DOT DSS MAX 7 1 2 7 1 2 1 A212 7 1 2 2 2 4 2 2 1 7 4 2 2 2 MAINTENANCE OF LINES TRUNKS amp SERVICE CIRCUITS Procedure Threshold alarm for trunks get raised when a large number of lines go 005 This section gives the procedure for handling conditions wherein suddenly lots of trunks go faulty in a short period of time If on the other hand individual trunks go out of service one after another and this leads to a threshold alarm for trunks in that TGP then refer the procedure given under section for handling System reports If the trunks have all gone OOS SE suddenly then follow the same procedure 7 1 1 2 given for lines If trunks have gone OOS SE during periodic routining then follow same procedure 5 4 2 2 as for lines If the trunks gone OOS SO then follow 7 1 1 3 Procedure for Handling Terminals Maintenance Reports Line Status Change Report STATUS OF LINE BECOMING INS LLO FAULT IN THE OUTSIDE PLANT i This indicates ground fault developing on the line If several lines go faulty simultaneously the likelihood of a cable going faulty is very high ii If the report comes for a single line do the following Check
86. PRI CARD SLT The status of the card can be displayed as INS NRM INS FRC or OOS SE INS NRM Card has been brought INSERVICE after performing the complete tests successfully INS FRC The Card has been made INSERVICE forcibly OOS SE The Card is faulty The status of a BRL Card can be modified to Out of Service by using CRP Command FRC TRML CARD OOS Similarly its status can be modified to In service by using CRP Command FRC TRML CARD INS without testing or PUT TRML CARD INS after successful testing Testing of Analog Digital Trunk Groups Analog TWT E amp M and Digital DTK trunk groups can be tested with the help of TST TGP command with the input parameters TGP NO Test set where Test set 403 for DTK CAS Test Set 401 for DTK CCS and test set 202 for Analog TGP Service Circuit Hardware Routine Maintenance Service circuits MFC TOGC ANNC and TTC should get tested at least once in 24 hours First of all check the status of all these service circuits through DISPL SRV STATUS command If there are already some service circuits OOS the operator should first attend to these according to the procedures given in Chapter 6 Procedure for Testing of MFC i The following test sets can be scheduled at low traffic hours using the TST SRV with test set 301 for testing the MFC ii If the test passes on all circuits then perform the same test on the next MFC and so on for all the equipped MFCs iii If
87. S NOTE CARDS ARE REQUIRED ONLY IN CASE OF CONCENTRATION OF ISTU FIG 3 9 5 ISTU CONFIGURATION 12 34 5 6 7 8 9 1011 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 P P 5 5 8 18 5 8 5 5 M 0 UI UUPIHIHHIHM 5 5 0 U EIMIMMIMICICII TICICIMIM MIM E lu U 1 2 1 2 4 OR 5 6 7 4 3 B B SHM _ 7 PROTOCOL HANDLER CARD NOTE i WITH BPC ONLY SHM1 2 3 AND 4 CAN BE EQUIPPED ii HPC IS USED TO SUPPORT SHM 1 TO 8 AND HIGHER MESSAGE PROCESSING CAPABILITY FIG 3 9 6 750 CONFIGURATION DESIGN DSSMAX MAX XL MAX MP2 MP2 7SU MAINTENANCE PROCEDURES 35 Chapter 3 123 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 2021 22 23 24 25 26 P 5 5885 516 5 5 5 5 8 5 U U II II 1 2 3 XX x x NOTE FOR SUPPORTING RBM XL CORRESPONDING PSM CARDS IN BOTH BUSES i e BTU amp 1 ARE TO BE REPLACED BY ESM CARDS MOREOVER FIG 3 9 7 BTU 1 CONFIGURATION 1 gt 34 5 B 7
88. S 0 card restore the original card force it in service and make it INS ACT Ensure that the service is not affected iii Now make BMS 1 OOS OPR and replace its controller card by a healthy card Bring this BMS in service and make it INS ACT MAINTENANCE PROCEDURES 99 Chapter 6 iv Diagnose BMS 0 again and if the diagnosis passes log BMS 1 as the faulty card Make it INS ACT and observe the service 6 4 1 4 2 CASE BMS SCIC DIRECT LINK TEST FAILED a FAULT PROB FOR MSD AND SCIC ACTIVE OR STANDBY CARD i Makethe BMS OOS OPR and diagnose ii If the diagnosis fails replace the MSC MSD card by a healthy card Diagnose BMS again and on passing bring it in service Make it INS ACT and observe the service for some time iii If BMS diagnosis fails restore the original card Make SCIC OOS OPR and diagnose If SCIC diagnosis fails refer to section 6 4 1 3 iv Diagnose both BMS and SCIC and on passing bring them in service Make them INS ACT and observe the service for some time 6 4 1 4 3 CASE BMS TSC DIRECT LINK TEST FAILED a FAULT PROB FOR MSC AND TSC ACTIVE OR STANDBY CARD i Makethe BMS OOS OPR and diagnose ii If the diagnosis fails replace the MSC card by a healthy card Diagnose BMS again and on passing bring it in service Make it INS ACT and observe the service for some time ii If BMS diagnosis fails restore the original card Make TS OOS OPR and diagnose If TS diagnosis fails refer to section 6
89. S MAX HARDWARE ARCHITECTURE f Lv edlWNedIA XV IAN DCXVIANXVINSSQWNDSIS3QN LSL 261 OL 1VIH3S 8 821 LINN IVNIWNH3 L L HOSS30OHd dS HOLIMS INIL SL H3TIOHINOO 3OVJH3INI 9IL VNINH3L 9L QHVOVNINH3L OL sna WNOIS sna viva HOSS300ud D 2 8 SINNT L e um 2 le e 891 e 291 21 gt SINIT L e 2 51264101 TJ 2 17 MAINTENANCE PROCEDURES Chapter 3 3 2 2 18 Signalling Processor SP Card Signalling Processor SP processes the signalling information received from the terminal cards This signalling information consists of scan drive functions like origination detection answer detection digit reception reversal detection etc The validated events are reported to Terminal Interface Controller for further processing to relieve itself from real time intensive functions Based on the information received from the Terminal Interface Controller it also drives the event on the selected terminal through scan drive signals Terminal Interface Controller TIC Card Terminal Interface Controller TIC controls the four terminal groups TG of 32 channels and multiplex them to form a duplicated 128 channel 8 Mbps link towards the Time Switch TS For
90. SONSVIQ Wo 20 601 HOS aassvd gt ALI V SI 0 6011 JO INL 9 SI 0 0LLL 40 INL dO ONILLAS p ALINVA SI 0 0LLL dO 211 2 ALI V 510 01 JO INL SI Quvog H3HLOW JHL 3NV Id MOVE 0 0LLL 40 QuVO INL OL Q3193NNOO 318V9 NOLLVHIN3ONOO LINYA E L1nv4 LS3H9IH ON SVH0QldH S3A ALINVA SI 0 6011 dO INL 2 SI 0 0 1 0 6011 N33M138 NOLLVHIN3ONOO ALINVA SI 0 0 Qu vO INI Salir vaogd LINYA ON NI INL LNO 0001 NI QU VO INL SI 0 6011 NI Q3193NNOO IN318O08d NOLLVH LN3ONOO 03 39 LHVHO 9 Old SI 0 6011 40 30 ONILLAS ALINVSA 510 6011 dO QHVO OIL 9 ALINVSA SI 0 6011 dO INL 74 SI H3HLON 30 MOVE JHL NI 0 601 L 40 INL OL Q3193NNOO 318V9 NOLLVHIN3ONOO AL avaoud rinva ON SHA LINYA 0 __ Q3SSvd SOLLSONOVIG 0 6011 HOS 1MS N9G SAID 0 0H L JO Qu VO INL LNO Chapter 6 C DOT DSS MAX 92 MAINTENANCE OF SWITCH UNI
91. TCH ALARM GIVE RESET TO BOTH COPIES OF THE FAULTY UNIT Y WAIT FOR SOMETIME Pd um Pd T 27 YES 7 RECOVER gt RECTIFIED a E JACKOUT ONE COPY om Fa tua 3 RECOVER RECTIFIED p ge JACKOUT SECOND COPY Y FIG 6 2 DESIGN DSSMAX MAX XL MAX XLMP MXLMPUF2 MAINTENANCE PROCEDURES 87 88 Chapter 6 p 5 SYSTEM Is ABLE YFS FAUT TO RECOVER RECTIFIED P P NO JACKOUT BOTH COPIES REPLACE ALL CARDS OF ONE COPY WITH A GOOD SET OF SPARE CARDS P die d P d rs _ 18 SYSTEM NO lt ABETO gt RECOVER EM YES pe an CONTACT THE S DESIGN CENTRE ALARM CHANGED Y URGENT J JACK IN ALL CARDS OF OTHER COPY _ FOR LOCALISING THE UNIT FOLLOW FLOW CHART GIVEN IN FIG 5 6 FOR M URGENT NON URGENT 4 SWITCHUNITFAULTS lt FIG 6 2 FLOWCHART FOR CRITICAL SWITCH UNIT FAULTS DESIGN DSSMAX MAX XL MAX XLMP MXLMPUF3 C DOT DSS MAX MAINTENANCE OF SWITCH UNITS If the system recovers check that normal service is restored Diagnose the standby copy to localise the fault and
92. TS HFO3dWTXIANdIN DCXVIAN TXCXVIANXXVINSSQNDOIS3QS IN318O08d NOLLVH LN3ONOO ONILOALAG LHVHO 9 9l SS31SI d318VO NOILVHLIN3ONOO ALINY SASVO NI L08 3181X3 14 LI OL LHVHO 93 SI 318 VO NOLLVH IN3ONOO ALINVA 40 ALON ALINY SI LINN NI GHVO LINYA ON 2 SIA SNLVLS LOV SNI LSSHDIH gt ALTANY 510 211 ONY NI OL SvH0dlaHvO 0 11 Nd3M138 WOSIO zIL e NOLLVHIN3ONOO 2 GENTES 0 LLLL O OHL ALINY 0 601L ONINIVINOO ON 810 441 JO INL d NIVHO 0 OIL WLOL m ANNY N 910 21 JO N 5 SHA ue LS3HOIH pet LINYA ON 7 59 4 amp O LLLL NI NI igdassvaoiui LINYA INL saa 7 JOSOLSONOVIO ON ALINVA SI 0 EHL AO INL 9 SNOUM SI 0 21 INL dO INL dO 9NILL3S P 510 211
93. UP CLK Note MAINTENANCE PROCEDURES 139 Chapter 8 That particular clock source should be equipped and its status should not be already OOS_OPR Further it should not be the clock source selected by the active NSC copy Output The report displays the result of the command as SUCCESS if the status of the clock source could be successfully changed to OOS_OPR Sample report CLOCK SOURCE DIAGNOSIS REPORT UNIT ID NSC 1 CLOCK SOURCE RCLK2 RESULT PASS NEW STATUS OOS OPR OLD STATUS INS TOBE Sample report CLOCK SOURCE DIAGNOSIS REPORT UNIT ID NSC 1 CLOCK SOURCE RCLK2 RESULT INVALID CHANGE NEW STATUS INS ACT OLD STATUS INS ACT 8 6 1 5 FRC NSC CLK OOS Force NSC Clock Out of Service Function To let the operator throw out any clock source of NSC Input parameters 1 NSC ID Possible values 1 0 2 NSC 1 2 CLOCK Possible values 1 RCLKO 2 RCLK1 3 RCLK2 4 USRN 140 C DOT 055 MAINTENANCE PROCEDURE FOR NETWORK SYNCHRONIZATION 5 DUP CLK Note The status of the clock source should not be UNEQUIPPED or OOS_OPR Output The result of the command is shown as SUCCESS if the clock source status could be made OOS_OPR successfully Sample report CLOCK SOURCE STATUS CHANGE REPORT UNIT ID NSC 1 CLOCK SOURCE RCLK2 RESULT PASS NEW STATUS OOS_OPR OLD STATUS INS_ACT If the excution of command itself fails the result shown is INVALID_CHANGE Sample report CLOCK SOURCE STATUS C
94. affecting other modules in the system Resources are identified as global or local depending upon their distribution in the system The resources which depend upon the number of terminals are provided within the basic growth unit the Base Module Base processors are provided for handling call processing locally In a small system application these processors independently support call processing exchange operation and maintenance functions On the other hand in order to avoid replication of large data and memory intensive functions some features and facilities are provided centrally Program backup bulk data storage man machine interface and operations and maintenance facilities are therefore provided centrally in order to provide a means of separating the switch from the operations and maintenance interface TECHNOLOGY The system employs a T S T switching configuration and is based on a 32 channel PCM structure It uses a basic rate of 64Kbps and 2Mbps primary multiplexing rate Control is distributed over the system by using 32 bit 16 bit and 8 bit microprocessors All the critical control circuitry has built in redundancy System hardware utilises advanced concepts in micro electronics for a compact and optimum design Basic memory unit has been implemented as a 16MB dynamic RAM board Single chip digital signal processors are used for implementing DTMF and MF receivers high performance high density VLSI chip detects multiple
95. aily so as to confirm the following 1 Periodic testing routining schedule is actually being done ii No unit or link remains in passive role for a long period iii No unit or termination remains un tested for a long period iv Routining was not abandoned in between Units or terminations are generally found in good health after routining vi Routining failures also result in generation of diagnostic reports alarm reports and appropriate alarms on the ADP In case above is not true further investigations are initiated 5 3 ROUTINE MAINTENANCE OF BASE MODULE BM This involves maintenance of Switch hardware Terminal hardware and service circuit hardware These aspects are described below MAINTENANCE PROCEDURES 65 Chapter 5 5 3 1 5 3 1 1 66 Switch Hardware Routine Maintenance Routine maintenance for the switch hardware should be taken up only in the low traffic hours typically in the night General Procedure for Testing of all Duplex Units 1 ii iii iv vi Note down the current status of all the switch units through DISPL SYS ALL command It is assumed that all the units are in duplex mode either active or standby state If any unit is OOS first attend to that fault using the procedure given in chapter 6 on the system trouble fixing procedures The order for routining should be such that a hierarchically higher up unit should be tested first and then the subsequent units The desir
96. al plant records whether the subscribers belong to the same distribution cable In such a situation the fault can be due to a problem in cable plant itself which is to be corrected Otherwise each line has to be treated separately as in Case I Telephone Held Up No Dial Tone 1 H iii In case subscriber complains of the telephone being held up then the likelihood is that speech battery is present but some ground fault is there To ensure this check the status of the subscriber on BM If the status indicates INS LLO for the line then confirm the fault by conducting outside plant open loop tests on the subscriber If the outside plant test passes then perform exchange side tests and confirm that there is no fault at the exchange side If there is fault at the exchange side the concerned line card should be replaced Permanent Ring i ii iii iv Check the status of the terminal Perform exchange side tests on the concerned subscriber If the exchange side tests fail the line card is to be replaced Perform closed loop tests on the line If closed loop tests fail most likely the fault will be in telephone instrument which has to be replaced Perform outside plant open loop test on the subscriber and confirm that there is no fault at outside plant Make check on other lines in the same TU Permanent Dial Tone 1 ii Check the status of the terminal Perform closed loop tests on the l
97. ant observations and maintenance actions Some of the above functions are briefly described in the following paragraphs Watch on System s Health This involves ensuring periodic dump of desired informations scanning reports generated by the system and verifying systems integrity with a view to uncover any abnormalities in system s behavior and being vigilant towards the audio visual alarms raised by the system Moreover when a new card is brought to service vigilance towards system s behavior is needed to uncover any malfunctions which can be attributed to the new card C DOT DSS MAX 5 2 1 1 5 2 1 2 5 2 1 3 ROUTINE MAINTENANCE Ensuring Periodic Dump of Desired Information System on its own initiative keeps generating various reports regarding system s health as and when significant events take place Maintenance personnel too can programme the system in advance for generating various periodic reports including the following Such reports are to be scanned daily to enable them to track system s health on a day to day basis i List of all switch units and terminals having OOS status ii List of all switch units found faulty by the system OOS SYS iii List of all terminals found faulty by the system OOS SE OOS SO INS LLO iv List of service circuits and trunks found faulty by the system or by operator v List of trunks having status as BLOCKED or as OOS TRANS Above reports can be generated by
98. arameter value should be at least 4 vii While displaying traffic reports related to hunt groups trunks amp routes the entry against MOD NO parameter in DISPL TRF RPT command should be MAINTENANCE PROCEDURES 155 Chapter 10 10 3 4 156 Known Constraints and Possible Alternatives i li iii iv While creating a trunk group more than 40 trunks should not be given at a time If more than 40 trunks are required in a trunk group trunks can be added using ADD TRK commands in the existing trunk group The status of more than 40 trunks cannot be displayed at a time in the same command The range of terminals given in DISPL TRM STATUS should not be more than 40 Alternatively the command DISPL TRCNT OOS can be used to know the breakup of more than 40 trunks After that DISPL TRM ALL can be used to find out the listing of trunks with a specific status In case of more than 100 trunks MOD TGP CHAR does not work Command is rejected with suitable error message To modify the characteristics the no of trunks should be reduced to lt 100 After modification the deleted trunks should be added In few cases modification commands for subscriber or Trunk Group Characteristics may fail with suitable error message prompting the user for corrective measures In such cases the subscriber or trunks should be attempted once again to make them out of service C DOT DSS MAX Appendix Test Sets I TEST S
99. ard using DBE facility Procedure for Handling Alarms in Central Module Alarm Raised For CM CASE ACCESS OF CLOCK OR SWITCH CARD FAILED i This error may be displayed because of fault in clock card or switch card The corresponding CBX SSBID card may also be faulty To isolate first interchange SSC and repeat the diagnosis If the diagnosis fails continue with next step ii If fault probability is shown for all switch cards replace the CBX card Otherwise replace the switch clock card for which the fault probability is shown and repeat the diagnosis CASE TDRA TEST FAILED This error is displayed during the diagnosis of IFC This test may fail due to IFC card being faulty or HMS card of one of the CMSs being faulty or BM CM link being faulty Replace the IFC card for which the diagnosis has failed and repeat the diagnosis If the diagnosis passes mark the IFC card as faulty If it fails make the TSC of the BMs corresponding to the IFC card TSC 0 for bus 0 IFC1 to IFC16 and TSC 1 for bus 1 IFC17 to IFC32 out of service and repeat the diagnosis If the diagnosis passes the BM CM link MAINTENANCE PROCEDURES 105 Chapter 6 6 4 2 1 3 6 4 2 1 4 6 4 2 1 5 6 4 2 1 6 106 may be suspected Replace the TSS ETS in case of RBM card of the BM make the TSC in service and repeat the diagnosis If the diagnosis still fails make one CMS of the corresponding bus CMS1 and CMSS3 for bus 0 and CMS2 and CMS4 for bus
100. as 1 and password as DSSlp LP subsystem commands i Changing of the device for physical printer prn1 to dev icc x IOP5x gt usr lib lpadmin pprn1 x ii Creation of a new physical printer prn1 on port dev icc_0 IOP5x gt usr lib lpadmin pprn1 v dev icc 0 mcdot iii Deletion of a physical printer IOP5x usr lib lpadmin xprn1 C DOT DSS MAX SYSTEM INITIALISATION amp MAINTENANCE PROCEDURE iv Creation of logical printer 1 having physical printer 1 If pr1 does not exist it is created If pr1 already exists 1 is added as an additional printer for that logical printer IOP5x usr lib lpadmin pprn1 1 v Deletion of logical printer 1 or removal of physical printer prnl association to logical printer If it is the only physical printer associated with the logical printer the logical printer is deleted IOP5x usr lib lpadmin pprn1 cpr1 vi Make a logical printer default system destination IOP5x gt usr lib lpadmin dpr1 vii Deleting the system default destination for print requests IOP5x gt usr lib lpadmin d viii Display of LP subsystem configuration IOP5x gt lpstat t ix Making a printer pr1 accept request IOP5x gt accept 1 x Making a printer reject new requests IOP5x gt reject pr1 xi Enabling a physical printer to print IOP5x enable prn1 xii Disabling a physical printer from printing IOP5x gt disable p
101. at time do not issue any man machine commands other than that which is absolutely necessary stop any repair action other than that which is very essential like both copies of a duplex unit has become OOS etc Abort IOP Synchronisation procedure if it was under progress at the time of overload Run audit for the resource that is overloaded viz message buffer audit if message buffers are overloaded ordinary buffer audit if ordinary buffers are overloaded etc Buffer size is also displayed in the report If the overload persists then proceed as follows Check if too many status change reports are coming for any set of terminals repeatedly on OOD If they are then make those terminals OOS OPR Check whether too many entities subscribers trunk group etc are put under observation If they are then remove them from observation MAINTENANCE PROCEDURES 111 Chapter 6 v If this overload persists for a long time gt 10 minutes contact the design centre and then the system should be rebooted softstart if necessary 65 PROCEDURE FOR HANDLING SYSTEMS REPORTS This sections deals with spontaneously generated system reports other than the alarm reports or those which come in conjugation with the alarm reports which has been separately dealt with in the previous section 6 5 1 6 5 1 1 6 5 1 2 6 5 1 2 1 6 0 1 2 2 12 Procedure Handling Switch Maintenance Reports Diagnostics Fail Report This has been
102. ately enable and disable the interrupt signals using control information present in the OBMP Control Register n the normal mode the control information is written into the control register by the OBMP and based on the status of various signals However it is possible for the CPU to exercise overriding control through communication with OBMP e Error like APE Address Parity Error DPE Data Parity Error and MVE Mode Violation Error on the CPU bus interface are combined and given as DERR to CPU The APE is given to the mate NSC 8 6 OPERATOR COMMAND SHEETS 8 6 1 MOD CLKSRC EQPAG Modify Clock Source Equipage Function To equip unequip a particular network clock source for both the copies of NSC Input parameters 1 OPR TYP Possible values 1 EQUIP 2 UNEQUIP 2 CLOCK Possible values 1 RCLKO 2 3 RCLK2 4 USRN Note 134 C DOT DSS MAX 8 6 1 1 MAINTENANCE PROCEDURE FOR NETWORK SYNCHRONIZATION For the Equip option the status of that particular clock source should be UNEQUIPPED for both the NSC copies For the Unequip option the status of that particular clock source should be OOS OPR for both the NSC copies Output The report displays the result of the command as a SUCCESS or FAILURE Sample report CLK SOURCE EQUIPPAGE MODIFICATION SUCCESS REPORT Operation Type Equip Clock source Rclk2 DGN NSC CLK Diagnose NSC Clock Function To let the operator diagnose a particular clo
103. attention since some of the concentration TUs may be down completely Determine which plane is the standby plane and fix the problem in that plane as described in the previous section When the problem is fixed on one plane the switching over of the planes will take place immediately After this follow the procedures described in the previous section to fix the problem in the new standby plane also Alarm Raised for TS CASE FAILED TO CONTACT TSC Explanations TSC card monitor is faulty BMS to TSC card link is bad standby Action Give a reset to TSC and repeat test again If it fails Change TSC If problem persists interchange BMS repeat commands or interchange SCIC repeat commands a FAULT PROB ONLY FOR TSS CARD ETS Card in case of RBM i If replacing TSS ETS in case of RBM card does not solve the problem then replacing TSC and finally TSM should be tried Reset the TSC after replacing any of the cards C DOT DSS MAX MAINTENANCE OF SWITCH UNITS b FAULT PROB ONLY FOR TSM CARD i If replacing TSM card does not solve the problem then replacing TSC and finally TSS ETS in case of RBM should be tried Reset the TSC after replacing any of the cards c FAULT PROB FOR TSC amp TSM CARD i Follow the general procedure except that while replacing the cards first TSM card should be changed If that fails to solve the problem then TSC and finally TSS ETS in case of RBM can be changed in
104. cal Card Slot or Unit id Involved Diagnosis Frame in in CRP Reports CM Cabinet 16 17 SSUO 2 BUS 0 COPYO 1 1 1 18 0 1 2 15 BUS 0 19 1 20 21 SSU1 3 BUS 1 176 C DOT 055 MAX 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 LIST OF CARD IDS IN SWITCH ALARMS amp POWER ALARMS FOR MAX XL Switch unit Cards Card IDs in Physical Card Slot or Unit id Involved Diagnosis Frame in in CRP Reports CM Cabinet BUS 1 1 BTUO 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 BTU1 4 MAINTENANCE PROCEDURES 177 Appendix C Switch unit Cards Card IDs in Physical Card Slot or Unit id Involved Diagnosis Frame in in CRP Reports CM Cabinet 0 0 0 0 0 0 0 0 0 0 0 0 0 0 i Space Switch Plane 55 0 1 consists of the following switch units UNIT IDs and if DGN SWU on SS 0 1 is conducted then all the units involved in the switch plane will be tested 1 SSBID 0 1 2 CLK 0 1 For physical slots refer 3 SWC1 0 1 to corresponding switch 4 SWC2 0 1 units in the chart 5 SWC3 0 1 6 SWC4 0 1 7 SWC5 0 1 8 SWC6 0 1 9 SWC7 0 1 10 SWC8 0 1 178 C DOT DSS MAX LIST OF CARD IDS IN SWITCH ALARMS amp POWER ALARMS FOR MAX XL 11 SWC9 0 1 12 SWC10 0 1 13 SWC11 0 1 14 SWC12 0 1 15 SWC13 0 1 16 SWC14 0 1 17 SWC15 0 1 18 SWC16 0 1 b POWER SUPPLY UNITS FOR DIFFERENT FRAM
105. ce Circuits Interface Controller Terminal Interface Controller within the BM and the four CMS complexes in CM It acts as a message transfer point between the Base Processor and these controllers It receives messages from the Base Processor and transmits them towards the appropriate controllers Note To support 8 00 000 BHCA MSC and MSD cards are replaced by a High performance Message Switch HMS with high speed 32 bit microprocessor MC 68040 It implements 38 HDLC links with flexibility of programming individual link for a speed upto 750 kbps Time Switch TS The Time Switch complex is implemented using three different functional cards as multiplexer demultiplexer TSM time switch TSS and time switch controller TSC The Time Switch complex receives the following PCM links and performs time switching on them for switching within the Base Module Four 128 channel multiplexed links from four different Terminal Units which may be any combination of ATU DTU 750 and ISTU One 128 channel multiplexed BUS from the Service Circuits Interface Controller SCIC in the Time Switch Unit Three 128 channel links to support onboard three party conference circuits 3 x 128 MAINTENANCE PROCEDURES 21 Chapter 3 3 2 6 3 3 3 3 1 22 It multiplexes above 128 channel links to form a dual 512 channel 4 Mbps multiplexed bus towards the Central Module The individual buses are called BusO and Busl Besides this it
106. changes In the beginning the telephone number where the fault is booked is written The complaint is registered with following details S no exchange code junction no date and time of booking complaint no fault booked sign of person booking fault reported back from distant exchange date and time of reporting back checked whether ok or not at our end Remarks for further action if not ok at our end Incoming Junctions Complaint Book In this register fault of incoming junctions reported by distant exchanges are booked The fault is booked with following details S no complaint no junction no booked fault reported date and time of booking signature of person booking TEN of junctions booked action taken time of reporting back to respective Exchange Here we have to give complaint no to distant exchange and after checking one junctions give the report to the exchange C DOT DSS MAX 9 3 LOGS TO MAINTAIN ix Billing Record Register A register should be maintained to keep a record of the cartridge sent for detail bill record and bulk counter reading x Generator Record Registers A register is kept to record the time for which the generator has been run in case of AC power failure xi Backup Register A register to record the billing traffic and data backup is maintained This contains the date expiry date signature of person taking the backup cartridge no used for backup Power Plant amp Enviro
107. ck as there is only one device enable for each NSC CBX pair The 2 048 MHz clock and 8 kHz sync signal are exchanged between the two copies of NSC Clock selection is done before the PLL block If all the inputs to the NSCs fail it runs in the holdover mode If the inputs are not restored till the end of the holdover period duration of the holdover period is defined in the Parameteric Specifications the NSCs go into the free run mode The NSCs work in mutual synchronisation as the PLLs track each other 8 4 DIAGNOSTIC FEATURES The following diagnostic features are provided on the NSC Cards Beat circuits to detect frequency drifts between the input clock pairs and input and output of PLL Selected clock monitoring for frequency failures and stuck at faults Sync failure detection logic to check for the presence of first frequency submultiples and multiples of 8kHz stuck at fault of sync signal and load pulse failure MAINTENANCE PROCEDURES 133 Chapter 8 USRN interface failure detection by making use of alarm signals Lock detection between the copies of NSCs and input and output of PLL e All the signals like address data and control in the CPU NSC interface are provided with parity bits TOD one Hz signal failure detection 85 ERROR REPORTING error signals described in 8 5 above latch the error in the OBMP Status Register and generate an interrupt to the OBMP e tis possible to separ
108. ck source of an NSC copy Input parameters 1 NSC ID Possible values 1 0 2 NSC 1 2 CLOCK Possible values 1 RCLKO 2 RCLKI 3 RCLK2 4 USRN 5 DUP CLK Note The clock source status for the requested NSC copy should be OOS_OPR Output The report displays the result of the command as a SUCCESS if the diagnostics were successful MAINTENANCE PROCEDURES 135 Chapter 8 Sample report CLOCK SOURCE DIAGNOSIS REPORT RESULT PASS REPORT OPTION UNIT ID NSC 0 CLOCK SOURCE The report displays the result as FAILURE if any of the diagnostic test has failed Sample report CLOCK SOURCE DIAGNOSIS REPORT RESULT FAIL REPORT OPTION UNIT ID NSC 0 CLOCK SOURCE 8 6 1 2 PUT NSC CLK INS Put NSC Clock In Service Function To let the operator bring in a particular clock source of an NSC copy after running diagnostics on it Input parameters 1 NSC ID Possible values 1 NSC 0 2 NSC 1 2 CLOCK Possible values 1 RCLKO 2 RCLK1 3 RCLK2 4 USRN 5 DUP CLK Note The status of the particular clock source for the specified NSC copy should be OOS OPR The specified NSC copy should be INS itself If the DUP clock of an NSC is attempted to be brought IN when the mate Switch plane is OOS the request rejected with reason CONFIG NOT SUITABLE 136 C DOT DSS MAX MAINTENANCE PROCEDURE FOR NETWORK SYNCHRONIZATION When the first network clock has to be brought INS the SEL CLK SRC command shoul
109. communicate with the copy to find out whether it is active or not If no reply comes from the copy it tries to become active by acquiring the memories If the AP BP is able to get at least one memory it will become active with that memory Code Load This level is triggered by software recovery or by operator command Patch Init This level is triggered by software recovery or by operator command Part Init This level is triggered only by operator command Stable Clear This level is triggered by software recovery or by operator command Soft Start This level is triggered by software recovery or by operator command C DOT DSS MAX 4 2 1 4 2 2 4 2 2 1 SYSTEM INITIALISATION amp IOP MAINTENANCE PROCEDURE In all the above levels of initialisation no new call is accepted by the module under initialisation However all the calls which were in progress are terminated forcibly at the end of initialisation Sequence of System Initialisation The system initialization sequence is as follows AM CM gt BMs gt SUM Only after the highest module has completed its initialization the lower module modules start their initialization However the levels of initialization for lower modules can be different If AM gets initialised to any level all other modules in initialised to stable clear STBL CLR In case of power ON code loading a maximum of 16 BMs can down load code patch at a time Remaining BMs will wait for the
110. cs fail restore the original card amp refer section on TS If diagnostics passes change the TSM card try diagnostics on SCIC iii If the problem persists change card also 6 4 1 3 3 CASE BMS SCIC LINK TEST FAILED a FAULT PROB FOR SCIC CARD AND MSC STANDBY COPY i If the problem persists after replacing the SCIC card restore the original card Make BMS OOS OPR and diagnose If the diagnosis fails on the BMS refer to section 6 4 1 4 ii Diagnose both SCIC and BMS If diagnosis passes make them INS ACT and observe the service for some time iii If diagnosis fails in the above step replace MSD card of the BMS complex b FAULT PROB FOR BOTH COPIES OF SCICs i Assume SCIC 0 is OOS SYS OOS OPR and SCIC 1 is INS ACT ii If the fault persists after replacing SCIC 0 restore the original card force it in service and make it INS ACT Ensure that the service is not affected iii Now make SCIC 1 OOS OPR and replace it by a healthy card Bring this SCIC in service and make it INS ACT iv Diagnose SCIC 0 again and if the diagnosis passes log SCIC 1 as the faulty card Make it INS ACT and observe the service 6 4 1 4 Alarm Raised for BMS 6 4 14 1 CASE FAILED TO CONTACT BMS a FAULT PROB FOR MSC CARD ALONE i Referthe general procedure given in sec 6 4 1 b FAULT PROB FOR BOTH COPIES OF MSC CARDS i Assume BMS 0 is OOS SYS OOS OPR and BMS 1 is INS ACT ii If the fault persists after replacing MSC of BM
111. ct this modular design has been consciously achieved by appropriate hardware practices The equipment practices provide modular packaging Common cards and advanced components have been used in the system hardware in order to reduce the number and type of cards Standard cards racks frames cabinets and distribution frames are used which facilitate flexible system growth Interconnection technology has been standardised at all levels of equipment packaging All these features together with ruggedised design make C DOT DSS MAX easy to maintain and highly reliable Another important feature of the design is the provision of both local and centralised operation and maintenance Beginning with local operation and maintenance with the installation of similar digital switches in the network centralised operation and maintenance will provide maintenance and administration services very economically All these services are provided through a simple interactive man machine interface FLEXIBLE ARCHITECTURE C DOT DSS is a modular and flexible digital switching system which provides economical means of serving metropolitan urban and rural environments It incorporates all important features and mandatory services required by the user with option of upgradation to add new features and services in future The architecture for the C DOT DSS is such that it is possible to upgrade a working MAINTENANCE PROCEDURES 7 Chapter 2 2 3 C DOT SBM or
112. cted to higher level and peer level exchanges It has an on board clock source also It gives a network synchronised clock and sync signals to the duplicated Central Clock cards CCK The CCK is controlled by the SSC through CBX The clock card generates its own clock and can be configured to select between the local clock and two copies of NSC clock Each clock card distributes 16 MHz clock and 8 kHz sync to self SSU and 16 MHz clock to all Bus Termination Units BTUs which receive buses from all the BMs connected to CM The CBX card provides an interface between SSC and SSU SSC makes any switch card access through CBX CBX also handles any power supply errors in SSU and BTU Each CCK CBX NSC complex form a security block i e cannot be used with CCK1 Thus there is a copy 0 complex and a 1 complex Fig 8 1 depicts the clock distribution in MAX XL MAINTENANCE PROCEDURES 131 Chapter 8 132 DTS 12 3 1 2 3 i xe i N N N N N N 16M NSC gt NSC 16M 1 16M 8k 16M 8k 16M 16 CBX 8K CCK 16M 16M CCK 8K CBX 2 1 1 16M 8K 16M 8K 16M 8K 16M 8K PSS PSS f 8K 8K PSS
113. ctions for the unit can be taken iii Check the status of all the switch units iv Confirm the fault i e diagnose all the units made OOS SYS as a result of the fault Note Before DGN SWU command can be issued for any unit the status of the unit should be made OOS OPR v If now the diagnosis passes refer section on transient faults vi Reset the controller card if involved and repeat step iv If the diagnosis passes now log this observation and report to design centre if diagnosis fails proceed to next step vii Jack out Jack in all cards which are in OOS SYS state Repeat step iv If the diagnosis passes now log this observation as momentary hardware problem in the card card slot at the appropriate place Otherwise replace the card having highest fault probability with a healthy card If there are more than one card with same probability start with the unit higher up in hierarchy vii Repeat step iv diagnose again to check whether the fault is removed or not MAINTENANCE PROCEDURES 83 Chapter 6 REFER CORR SECTION FOR THE ALARM RAISED Y RESET THE CONTROLLER CARD DIAGNOSE THE UNIT PASSED PUT LOG THIS 1 OBSERVATION AND REPORT _ DIAGNOSTICS THIS UNIT INSERVICE 7 TODESIGN CENTRE lt NO x X N FLOWCHART FOR URGENT NON URGENT SWITCH UNIT FAULTS ee URGENT NON URGENT ALARM ON ADP
114. d Administrative Processor This communication is used to access office data for routing inter module calls and administration and maintenance functions Fig 3 6 depicts the Central Message Switch in C DOT DSS ADMINISTRATIVE MODULE AM Administrative Module AM consists of a duplicated 16 32 bit controller called the Administrative Processor APC It communicates with Base Processors via the Central Message Switch for control messages and with the duplicated Input Output Processors in the Input Output Module for interfacing peripheral devices Administrative processor is responsible for global routing translation resource allocation and all other functions that are provided centrally in C DOT DSS MAX The implementation of AM is similar to Base Processor Complex of BM using the same hardware configuration As explained earlier HPC instead of BPC is used to support 8 00 000 BHCA INPUT OUTPUT MODULE IOM Input Output Module consists of duplicated Input Output Processor IOP The Input Output Processor IOP is a general purpose computer with UNIX Operating System It is used as the front end processor in C DOT DSS It handles all the input and output functions in C DOT DSS The IOP is connected to AP BP via HDLC links During normal operation two IOPs interconnected by a HDLC link operate in a duplex configuration Working as front end processor it provides initial code down load to the subsystems man machine interface and
115. d also its copy id In multimodule Check the status of the TICs in that TU Check the LEDs on the suspected PSU Power off and on or jack out and jack in the PSU card Check whether the PSU alarm gets removed If the fault gets repaired then log it as a transient hardware problem and keep the card under observation Otherwise replace the PSU card Check whether the PSU alarm on ADP OOD and alarm list gets removed vii If the alarm is removed then the fault is repaired viii Even after replacing the PSU if the fault persists then check the backplane The common kinds of faults in the back plane are bent connector pins on the front side or the pins on the back side shorting with one another some connector coming out wire rupturing and shorting with the pins etc If the fault got identified on the backplane restore back the original PSU card Note The chances of faults mentioned in viii occurring in a working exchange are very less Urgent Power Supply Alarm for TSU 1 Check the alarm on printer and alarm list From the power alarm report or using DISPL ARM LIST find out the identity of the copy of PSU in TSU which has gone faulty C DOT DSS MAX 6 4 3 3 6 4 3 4 MAINTENANCE OF SWITCH UNITS Note The PSU id is denoted by the copy of BMS to which that PSU is supplying power to Refer appendix C for PSU ids in power alarms ii Check the status of all the units in the BM
116. d be used If PUT NSC CLK INS is used it will be rejected with result CONFIG NOT SUITABLE Output The report displays the result of the command as SUCCESS if the clock source could be brought INS successfully The status awarded could be INS TOBE INS COLD as outlined in the design document Sample report CLOCK SOURCE DIAGNOSIS REPORT RESULT PASS UNITID NSC 1 CLOCK SOURCE NEW STATUS INS_TOBE OLD STATUS OOS_OPR If the diagnostics of the clock source fail then the result displayed is FAILURE Sample report CLOCK SOURCE DIAGNOSIS REPORT RESULT FAIL UNITID NSC 1 CLOCK SOURCE NEW STATUS OOS_OPR OLD STATUS OOS OPR If the execution of command itself fails the result shown is JOB ABORTED and in some specific cases like mate SSC not INS it is displayed as CONFIG NOT SUITABLE Sample report CLOCK SOURCE DIAGNOSIS REPORT RESULT JOB ABORTED UNITID NSC 1 CLOCK SOURCE NEW STATUS OOS_SYS OLD STATUS OOS_SYS MAINTENANCE PROCEDURES 137 Chapter 8 6 1 3 138 8 FRC NSC CLK INS Force NSC Clock In Service Function To let the operator bring in a particular clock source of NSC without running any diagnostics Possible values 1 NSC ID Possible values 1 0 2 NSC 1 2 CLOCK Possible values 1 RCLKO 2 RCLKI 3 RCLK2 4 USRN 5 DUP CLK Note 1 The status of the clock source should be OOS 2 The specified NSC copy should be INS itself 3 If the DUP clock of an NSC
117. d synchronisation is provided by a source within the Base Module It is a very useful application for small urban and rural environments With minimum modifications in hardware through only one type of card a Base Module can be remotely located as a Remote Switch Unit RSU parented to the main exchange using PCM links Central Module CM consists of a message switch and a space switch to provide inter module communication and perform voice and data switching between Base Modules It provides control message communication between any two Base Modules and between Base Modules and Administrative Module for operation and maintenance functions It also provides clock and synchronisation on a centralised basis MAINTENANCE PROCEDURES 9 vS edNNedW XVIAN DCXVIANXVINSSQNDIS3Q NV WALSAS 3gnoiJ AHVWWIHd Idd 3OVJH3INI3l1VHOISVH 1 MYOMLAN S39IAH3S Q31VHO31NI NASI Z ON 9NITIVNOSIS T3NNVHO NOWINOO 2599 GALVIOOSSV TdNNVHO SVO LINN HOLIMS 31OW3H NSH TER 15 3INVH3 NIVIN gt TANVd WHv1V LNdLNO WO JINON 151 WY WHLNSD WO JINON ng WOI S3OVH31NI 5158 WOu3 SANNYL 1500 8 570 SANNYL WLISIG SYMNNYL
118. data storage for billing and other administrative information Refer Fig 3 7 for IOP connectivity in the system and IOP VH architecture IOP VH Hardware Architecture The IOP VH is value engineered high performance IOP designed using a single card The IOP CPU uses MC 68040 25 MHz processor on the VHC card It has 16 MB expandable to 32 MB onboard DRAM and 512 KB C DOT DSS MAX HARDWARE ARCHITECTURE SINO edWedW XVIAN DCXVIANXVINSSQWNDIS3QY HOLIMS ADVSSAW TIVH LN3O 9 AYNOSIA sdqwy SLOTS ZLS sna 255 1016 INIL 5 H3TIOHLNOO HOLIMS 3095 OSS HOLIMS 55 SWO H3TIOHLNOO 5 3ALLVHLISINIWQV OdV osna isna C gt 1 58 2 81 LS LOIS INIL 9 51015 2 _ ya quet m MD pc 2 gt 5 lt P dol a 98 ees OL m Ka 4 P lt 50 1 51 5 S LOTS INIL v9 SLOTS isna sna WO XPIW3Q XhlN 27 MAINTENANCE PROCEDURES Chapter 3 OIG ed Ned IW XVIAN DCXVIANXVINSSQNISIS3Q 3dnioaliHOHV HA dOI LOQ O STVNIWH3L H31NIHd HO 1HOd 51908 OlSV 8 1SOH 310SNOO Z 13
119. de of Remote Switch Unit as well as in case of Single Base Module Exchange SBM RAX For these functions the Base Module hardware is spread over different types of units Analog Terminal Unit to interface analog lines trunks and providing special circuits as conference announcements and terminal tester Digital Terminal Unit for interfacing digital trunks i e 2Mbps E 1 PCM links 7 Signalling Unit Module to support SS7 protocol handlers and some call processing functions for CCS7 calls MAINTENANCE PROCEDURES 15 Chapter 3 e ISDN Terminal Unit to support termination of BRI PRI interfaces and implementation of lower layers of 0551 signalling protocol Time Switch Unit for voice and message switching and provision of service circuits Base Processor Unit for control message communication and call processing functions 3 2 1 Analog Terminal Unit ATU Figure 3 1 The Analog Terminal Unit ATU is used for interfacing 128 analog terminations which may be lines or trunks It consists of terminal cards which may be a combination of Line Circuit Cards LCC CCB with Metering CCM cards Two Wire Trunk TWT cards E amp M Two wire EMT Trunk cards and E amp M Four wire EMF trunk cards depending upon the module configuration Also provision has been made to equip Conference CNF card to support six party conference Announcement ANN to support 15 user friendly announcement messages and Term
120. e cards Start jacking in one line card at a time and simultaneously start bring them into service If the first line card itself fails to come into service then suspect the line card or the backplane as faulty Otherwise keep jacking in cards and bring them into service until a point where not only one of the cards that is jack in fails come into service but also other inservice lines go OOS when this particular card is jacked in Replace the card with a good spare Bring all the lines back into service CASE ROUTINING FAILED ON SEVERAL LINES 1 H Suspect the sanity of TTC Perform the same test which had failed in some good lines within the switch room If the tests fail then either the TTC or the test bus is faulty iii Force all the lines that have gone OOS into service Check that calls go iv through on these lines Replace the TTC with a good spare Again test some of the lines in the switch room If the tests pass now then log that it was TTC that was faulty If still the tests fail then it must be the test bus that has gone faulty The common type of fault is TA relay on any line or Trunk card getting permanently operated To identify which is the faulty card follow the procedure given under the heading alarm raised for TTC Threshold Alarm for a Trunk Group Indication LED flashing on ADP accompanied by an audio alarm The total number of trunks faulty in the system will also be indicated on the AD
121. e facility to the operator to have multiple printers connected to IOP and choose any of these printers to take printouts This section describes how to configure the LP subsystem MAINTENANCE PROCEDURES 57 Chapter 4 58 Logical Printer Each IOP has eight logical printers They are to be named as prX where X varies from 1 to 8 The requests from CRP OOD and ORP Operator Recognition Process are issued for these logical printers and it is assumed that all eight are always there These logical printers are mapped to some IOP ports to which the printers are connected This logical printer to port and hence physical printer mapping is changeable through the LP subsystem commands More than one logical printer may be mapped to one physical printer and more than one physical printer may be attached with one logical printer The figure below gives configuration which is present in the system by default This configuration need not be changed Logical Printer Physical Printer pri pr2 gt prnl dev icc 0 pr3 pr4 The system is configured as i Four logical printers pr1 to pr4 ii Physical printer prn1 iii All logical and physical printers accepting the requests iv Physical printer is enabled v Logical printer prn1 is the default destination printer The LP subsystem configuration is done using following LP subsystem commands All commands need to be given from LP account which is LP administrator Login
122. e of any clock source is reported on the OOD indicating both the old and new status of the NSC clock source SAMPLE REPORT ON OOD FOR CLOCK SOURCE STATUS CHANGE CLOCK SOURCE STATUS CHANGE REPORT UNIT ID CLOCK SOURCE OLD STATUS NEW STATUS NSC 1 RCLK2 INS ACT OOS OPR 8 9 MAN MACHINE INTERFACE Man machine commands have been provided as part of the exchange software for supporting NSC functionality in the MAX XL system The commands are listed below e PUT NSC CLK INS To put in service a clock source in any copy of NSC after diagnostics FRC NSC CLK INS To force in service a clock source in any copy of NSC PUT NSC CLK OOS To put out of service a clock source in any copy of NSC FRC NSC CLK OOS To force out of service a clock source any copy of NSC e DGN NSC CLK To diagnose the clock source in a copy of NSC SEL CLK SRC To select a clock source in both NSC copes DISPL CRNT CLK SRC To display the currently selected clock source in active NSC copy MOD CLKSRC EQPAG To modify the equipage status of a clock source for NSC 8 10 MODES OF OPERATION e Free Run Mode When none of the network reference clocks are available and no locking to external reference has taken place before Locked Mode When one or more primary reference clocks are available NSC enters into locked mode by selecting one of the available network clocks according to fixed priority and synchronises to it Holdover Mode
123. e other copy BP out of service PUT SWU OOS Change the copy BP Note This is to be done only after ensuring that the card which failed in diagnostics has no other problem other than watchdog circuit fault Alarm Raised for MU FAULT PROB FOR BME AND BPC CARDS 1 Follow the general procedure ii Replace the corresponding BME card and do diagnosis Ifit passes interchange and do diagnosis again iv Ifit passes again bring this inservice vi If it fails replace current standby BPC make it active and do diagnostic Alarm Raised for ADP i First give a reset to ADP and perform the LED test on ADP ii If LED test has failed then ADC is faulty and it has to be replaced iii Otherwise if LED test passes try bringing the ADC inservice C DOT DSS MAX MAINTENANCE OF SWITCH UNITS iv If it still fails check the link between the ADP and AP BP Check that the 6 4 1 8 6 4 1 9 6 4 1 9 1 6 4 1 10 6 4 1 10 1 connectors at the ADP are properly connected If there is no problem in the cable perform switchover of AP BP and try to bring ADC into service vi If ADC comes inservice now then the link from ADC to one copy of AP BP is faulty Try replacing the BPC card of standby AP BP Make it active and see whether the ADC remains inservice vii If the ADC goes OOS again then the fault is in ADC Replace back the old in Now fault is in ADC Alarm Raised for IOP
124. e units other units will share its load preventing disruption of service In case of certain service circuits n 1 configuration is used for maintaining reliability COMMON HARDWARE UNITS Various hardware units such as controller complexes and message switches have been standardised for multiple applications This interchangeability is an important feature of the system hardware that helps in reducing inventories and increasing system availability Some of these standardised units are Module Control Unit Module Control Unit is a 16 bit or 32 bit microprocessor complex with associated memory unit The same unit can be used as the Base Processor Unit in the Base Module or as the Space Switch Controller in the Central Module or as the Administrative Processor Unit in the Administrative Module C DOT DSS MAX 2 9 THE C DOT 055 FAMILY Interface Controller This is an 8 bit microprocessor based unit with a time switching network that can be used to control either terminal interface in the Terminal Unit or service circuit interface in the Time Switch Unit In both the cases its function is to assign time slots on the 128 channel link between the terminals subscribers trunks etc and the module time switch Message Switch Message Switch is implemented as a 32 bit message switch controller which provides upto 38 HDLC ADLC links for message communication between controllers In the Base Module the message switch can also be impl
125. ecautions to be taken logs to be maintained and feedback to be furnished to the repair centre Chapter 10 indicates DOs and DON Ts of the maintenance Appendix Finally as a quick reference to the test set numbers audit set numbers card IDs test IDs etc a complete list of these is provided in the appendices Pre requistics General familiarity with the maintenance capabilities of the system is assumed Description of maintenance commands detailed description of alarms and reports generated by the system do not come under purview of this document Such aspects have been covered under respective maintenance related documents as Maintenance Commands and Alarms amp Reports 6 C DOT DSS MAX 2 1 2 2 Chapter 2 The C DOT 055 Family GENERAL C DOT DSS MAX is a universal digital switch which can be configured for different applications as local transit or integrated local and transit switch High traffic load handling capacity upto 8 00 000 BHCA with termination capacity of 40 000 Lines as Local Exchange or 15 000 trunks as Trunk Automatic Exchange the C DOT DSS family is ideally placed to meet the different requirements of any integrated digital network The design of C DOT DSS MAX has envisaged a family concept The advantages of family concept are standardised components commonality in hardware documentation training installation and field support for all products and minimization of inventory of spares Infa
126. ed If only few of the TICs are failing with the above message then either the TIC TUI SPC ISP In exceptional fault may be with individual channels in TSM TSI or the corresponding cable is faulty Normally cable faults do MAINTENANCE PROCEDURES 89 Chapter 6 6 4 1 1 2 6 4 1 1 3 90 not occur in the field Instead the cable may not be making proper contact with the connectors because of improper harnessing Latches and latch frames should be used for locking the cable onto the shroud Change TIC or TUI and SPC ISP Check Cable position and harnessing desired only during installation Change TSM or TSI of TSU frame If problem does not get solved by any of the above then it is possible that the corresponding ADLC in BMS could be faulty If so BMS diagnostics should fail If BMS diagnostics fails then attend to the BMS problems first Refer the section of BMS faults If the test passes with one BMS active and fails with another DGN SWU for TIC BMS active then also the problem can be isolated to the BMS and the MSD card can be changed CASE TIC SP TESTS FAILED Explanation SP could be faulty TIC could be faulty in the SP interface logic Action Change the ISP card if problem persists Change the TIC card Even if the diagnostic report declares only SP card faulty replacing TIC card could be tried on failure of the general procedure to rectify the problem If this rectifies the problem then log the fault
127. ed order for routining is BP MU BMS SCIC TS TIC First the standby unit say BP 1 should be made OOS OPR using PUT SWU OOS command Note this action will lead to a switch alarm getting raised on ADP and OOD and report on the printer Next diagnose this unit using DGN SWU command If the diagnostics passes bring the unit into service using PUT SWU INS or FRC SWU INS command If the diagnostics fail follow the procedure given in the chapter 6 on system trouble fixing procedures After the unit has come as inservice standby issue the INTCHG command to make it active If the switchover is successful then repeat steps iii and iv on the other copy also say 0 i On the other hand during switchover if one of the adjacent unit becomes OOS SUS then the cross links from the unit BP 1 to that unit say IOP or ADC or BMS should be suspected Wait for the system to complete the diagnostics and see if it declares some unit faulty If it does refer chapter 6 on Trouble Fixing Procedures If it does not refer section on Transient Faults Handling vii If the routining of both the copies of a unit is completed then leave the unit in a configuration such that the copy which was earlier active is now the standby Proceed onto the next duplex unit and repeat the process Note that in case of MU both the copies are active So the procedure for MU is slightly different in the sense that after successfully diagnosing one o
128. eign potential test 20 Insulation resistance 21 Insulation capacitance 6 610 Complete test on U S interface 4 B Channel loopback test with NT 5 B and D Channel loopback test with NT 6 S interface activation deactivation test 19 Interface voltage foreign potential test 20 Insulation resistance 21 Insulation capacitance Note 1 The TLC Test Line Circuit is a BRI interface in C DOT DSS which is free and configured as TLC The circuit is used to simulate NT conditions to test the BRI interface 2 For PRI only test sets 607 amp 610 are valid d TST TRML CARD command is used for Test sets 605 amp 606 and valid for both BRL amp PRL C DOT DSS MAX Appendix B Audit Sets The audit sets and audits constituting them currently available in C DOT DSS MAX are summarised in the table bnelow followed by a brief description of each Audit Name MBM Config SBM Config cw weowsmws fy 3 Y fy v 171 fy x 5 wmowsaon fy v 5 aupamreappe Y x ity v Py v 5 wpsmuw x fy v 5 Jwmmmamk v py v w wma ____ x fy v ____ x Ea oma DN STALONE CCM STATUS mM E MAINTENANCE PROCEDURES 165 Appendix B 166
129. elds as follows Refer Fig 3 9 16 TEN XX X X XX XX Fields 1 2 34 5 The first four fields uniquely identify the card slot number as explained above in sec 2 5 The fifth field identifies the circuit number as explained below Fig 3 9 17 below illustrates the translation process for a TEN TEN 1 3 4 5 BM No Rack No Frame No Card Slot No Circuit No In case of Line Module a typical TEN can be 1 2 6 22 1 The value 2 for the Rack No signifies more than one rack i e BM has been concentrated C DOT DSS MAX HARDWARE ARCHITECTURE 63INdWTXIANdW DCXVIANDCXVIANXCVINSSQWNDSIS3QN NOILVO2OT 1VOISAHd OLNI NAL V ONILWISNVYL LL 7 0L L7 ON INS Ww Z ON MOVH NSL eni LAL 4 ON LOT1S N x f y G Nal TVNIINH3LL ON MOV 45 MAINTENANCE PROCEDURES Chapter 3 46 3 10 2 Fan Failure Detection Unit Fig 3 9 17 Forced air cooling units are provided in CM XL due to its relatively high dissipation of heat A cooling unit is a set of 2 DC powered fans housed in a mechanical assembly alongwith a Fan Failure Detection FFD card Three such units are equally spaced in a mother board in each pla
130. em whenever switchover request is a the command got executed but because of the switchover some other unit has becomes 005 505 b totally rejected for a unit because in the new configuration the system is unable to provide service INTERCHANGE HAS TAKEN PLACE BUT ADJACENT UNIT GONE SUSPECT i In this case most likely the OOS SUS unit will be declared OOS SYS in which the operator has to follow the procedure given in for System Alarms ii However in certain cases like for example after BP switchover one MU might go OOS SUS come into service and OOS SUS again and this keeps happening indefinitely Under such circumstances perform a BP switchover again make the memory that is suspected OOS OPR and diagnose it In this configuration the diagnostics will MAINTENANCE PROCEDURES 113 Chapter 6 6 5 1 3 2 2 6 5 2 6 5 2 1 114 catch the fault Follow the procedure given for handling BP MU faults In order to change status of MU from OOS SUS to OOS OPR give frc swu oos for that MU and then give reset to an inservice SBY TIC 11 If after BP switchover one BMS keeps going OOS and then being in service then the fault might be in that BMS or the currently active BP Try replacing the MSC of BMS first and see if the problem goes off Otherwise replace the BPC card of BP which is currently active INTERCHANGE DOES NOT TAKE PLACE i This happens because in the new configuration the system is unable to come up alt
131. emented as a 16 bit message switch controller and a message switch device card In such an implementation the controller provides upto 22 HDLC ADLC links with the help of the device card OPTIMISATION In C DOT DSS distribution and centralisation of functions have been optimised There are local functions which are entrusted to the growth units 1 the Base Modules for local switching and interfacing These functions use resources whose requirement is directly linked with the number of lines and trunks equipped These functions are Terminal Interfacing interfacing lines analog and digital trunks CCM PBX and remote digital lines Circuit Switching switching within the Base Module Call Processing majority of call processing functions Concentration for providing upto 2024 subscribers on 512 time slots On the other hand the functions that are shared globally over the switch are provided by a central facility which may either be the Central Module or the Administrative Module These functions are Inter module Communication Inter BM and BM AM communication via the Central Module Message Switching Inter BM and BM AM control message communication via the Central Message Switch in the Central Module Resource Allocation Done by the Administrative Module MAINTENANCE PROCEDURES 13 Chapter 2 Operations and Maintenance Bulk data storage by the Input Output Module and man machine interface provided by the
132. es the function of NSC card is achieved by external add on synchronization equipment C DOT NSE In this mode of operation the system works on external clock received from C DOT NSE instead of using its own clock However in exceptional case of failure of both the clock sources from C DOT NSE the system has provision to switch over to its own clock A brief description of implementation of Network Synchronization in C DOT DSS using NSC card along with its functional block is explained below Function of NSC Card The NSC card forms the interface between DTS Digital Trunk Sync and the CCKs Central Clock Cards It receives the 2 048 MHz reference input clock from DTS and converts it into a 16 384 MHz clock using a PLL Phase Locked Loop This clock is fed to both copies of CCKs It also generates a sync signal 8 kHz and feeds it to the CCKs for further distribution to all the BMs There is a Time of Day TOD block which generates the real time clock for the system It takes the input from DTS card a one hertz clock and embeds this in the 8 kHz sync The NSC has an On Board Micro Processor to take care of the PLL functions diagnostics communication with SSC C DOT DSS MAX 3 6 2 3 7 3 8 3 9 HARDWARE ARCHITECTURE Duplication and Security block The NSC card is duplicated and its access is similar to CBX cards The NSC and CBX form a security block as there is only one device enable for each NSC
133. es on all terminals configured and operator is allowed to login After login CRP prompt comes and the operator can execute crp at this level Only certain commands are allowed at this level of initialisation in which AP BP will not be able to communicate with IOP MAINTENANCE PROCEDURES 51 Chapter 4 4 3 4 52 Disable Update DIS UPD ALL This level is in between INSERVICE and WARM START levels and can be reached either from an inservice level or warm start level by init iop command At this stage IOP will have all eternal processes running in the system but no RCV commands are allowed from operator No operator feature is allowed at this level AP BP is able to communicate with the IOP if this level is attained through INIT IOP command on IOP which was running at Inservice level Disable Update Operator DIS UPD OPR INIT IOP command can be used to bring IOP to this level This is a level between Disable UPD and Inservice This level is reached from an Inservice level or Disable level At this stage operator features and subscriber initiated features are allowed but operators are not allowed to execute RCV commands AP BP is able to communicate with the IOP if this level is attained through Init Iop command on IOP which was running at Inservice level Inservice INS ACT INS SBY This initialisation is triggered by init iop crp command for IOP At this level the IOP is inservice
134. f the copies and bringing it into service the copies need not be switched over The other copy can be made OOS OPR and diagnostics can be started on it It is desirable that the entire switch hardware be routined at least once in a week Ensure the following four configurations of Switch H W during a 4 day cycle after performing tests C DOT DSS MAX 5 3 2 ROUTINE MAINTENANCE a Active BP0 BMS0 SCICO TSO TICO All TICs Standby BP1 BMS1 SCIC1 TS1 TIC1 Active BPO BMS1 SCICO TS1 TICO Standby BP1 BMS0 SCIC1 TS0 TIC1 Active BP1 BMSO0 SCICI1 TSO TIC1 Standby BPO BMS1 SCICO TS1 TICO 7 d Active BP1 BMS0 SCIC1 TS1 TIC1 l Standby BP0 BMS1 SCIC0 TS0 TICO In the above schemes all units get checked as active as well as standby within 4 days and no link remains unused beyond 4 days Each unit gets exhaustively tested at least once within 48 hours for all it s functions x When a switch unit previously not in active service is brought into active service it is worth while to watch system s behaviour for any possible abnormality This is most essential in case the unit happens to be repaired recently For example make a call to and from a TIC which has just been switched into active service Note The entire procedure of periodic routining of switch units can be fully made automatic by entering the entire schedule into the calendar At the appropriate time the calendar will invoke the desired test and if the
135. fault will be in the telephone instrument ii Perform closed loop tests on the line If closed loop tests indicate fault in the telephone instrument then telephone has to be replaced 7 2 8 One Way Speech i Perform exchange side tests and confirm that there is no fault at the exchange side If there is fault at the exchange side then the concerned line card should be replaced ii Perform closed loop tests on the line If closed loop tests indicate fault in the telephone instrument then telephone has to be replaced MAINTENANCE PROCEDURES 129 Chapter 7 7 2 9 Ringer Cadence not i Ifthe problem is occurring on all the lines of that TU replace PSUI which is towards the active copy of TIC Check that the problem is rectified ii If the problem is not occurring on all lines of that TU then the telephone instrument must be faulty 130 C DOT DSS MAX 8 1 Chapter 8 Maintenance Procedure for Network Synchronization INTRODUCTION The Space Switch Controller Unit SCU in the CM XL cabinet has duplicated SSCs 16 MB memory cards Base Memory Card BME CBX CCK and duplicated NSC cards The SSC checks the health status of all these cards and reconfigures the system in case of any faults There two duplicated devices are NSC Network Synchronisation Card and CBX Central Bus Extender Card NSC synchronises the local clock of the exchange with the network clock It gets input clocks from digital trunks conne
136. fecting or is likely to affect the service appreciably gets reported on ADP in the form of alarm to the operator The alarm indications in the form of a flashing LED accompanied by an audio alarm The same alarm gets displayed as an alarm report on OOD and also gets printed on the printer Depending upon the severity the alarm can be 1 Non urgent 1 Urgent iii Critical Non urgent alarm is indicated on the ADP via a green LED Urgent by an orange LED and Critical by a red LED The alarm of greater priority should be attended to first before other alarm Switch alarms will be raised for units in OOS SUS OOS SYS and OOS OPR states Procedure for Handling Switch Alarms in Base Module Indication C DOT DSS MAX MAINTENANCE OF SWITCH UNITS Flashing LED against the module in which the fault has occurred accompanied by an audio alarm on ADP alarm report on OOD and a printout of the alarm on the printer The unit ID in the module can be known from OOD or printer In case of SBM RAX ADP itself indicates the faulty unit PROCEDURE FOR HANDLING URGENT NON URGENT SWITCH UNIT FAULTS Refer Fig 6 1 For non critical faults the LED on ADP will either be green for non urgent or orange for urgent alarm 1 Check the alarm on ADP and printer ii Study the Diagnostics Failure Report on printer for cards declared faulty and the test that has failed Depending on the reason for the failure corrective actions mentioned in specific se
137. from some of the in service units which necessitates immediate C DOT DSS MAX 6 5 1 3 6 5 1 3 1 6 5 1 3 2 6 5 1 3 2 1 MAINTENANCE OF SWITCH UNITS attention i e one of the switch units might have gone OOS SUS status This might have happened coincidentally in which case it will not be of repetitive nature and will not need any special attention On the other hand this fault might be due to exercising of some part of the system by diagnostics which is not normally exercised In such case the problem will be of repetitive nature Under such cases note the configuration of the system under which the problem is occurring Try to recreate the problem by bringing the system to the same configuration and issuing the diagnose command from the operator position Repeat a few times Report the observation to the support centre Switch Unit Interchange Report This report is outputted by the system whenever switchover request is given for unit SWITCH UNIT INTERCHANGE REPORT RESULT NOT RECONFIGURABLE This report is output by the system whenever switchover request is rejected for a unit because of the configuration of the system at the time the command was issued The operator needs to do the following i Check whether the unit was in duplex operation ii For successful switchover for SCIC besides SCIC TOGC should also be in duplex SWITCH UNIT INTERCHANGE REPORT RESULT FAIL This report is outputted by the syst
138. ful Only if the level 2 alignment fails the test fails F Test details on digital cards BRL PRL The following test sets are carried out with command TST TRML CARD amp TST TRM S No Test Set Test No Test Details 605 16 Power on test on the BRL PRL 606 1 2 3 7 9 10 12 13 16 Test on interface on the exchange site LT of BRL PRL B Channel loopback test at LT end D Channel loopback test at LT end Line activation deactivation test IDEC functionality tet NT activation and deactivation test using TLC CRC generation recognition test using TLC TLC indication bit test or UID event detection test TLC line loopback test Power on test on the terminal card MAINTENANCE PROCEDURES 163 Appendix 164 S No Test Set Test Test Details 3 607 Interface test towards exchange side LT of BRL PRL 1 B Channel loopback test at LT end 2 D Channel loopback test at LT end 3 Line activation deactivation test 7 IDEC functionality test 9 NT activation and deactivation test using TLC 10 CRC generation recognition test using TLC 12 TLC indication bit test or UID event detection test 13 TLC line loopback test 4 608 Test on U S interface towards user 4 B Channel loopback test with NT 5 B and D Channel loopback test with 6 S interface activation deactivation test 5 609 External network condition test 19 Interface voltage for
139. he procedure given in Section 6 4 2 1 1 CASE SSC DIAGNOSIS FAILED i Replace the BPC card and repeat the diagnosis If it passes mark the BPC card as faulty ii If mate watchdog test is failing force the SSC in service put the other SSC OOS replace the BPC card and put in service Now make the other SSC OOS and do diagnosis If the diagnosis passes now mark the BPC card as faulty C DOT DSS MAX 6 4 2 1 7 6 4 2 2 6 4 2 2 1 6 4 2 2 2 6 4 2 3 6 4 2 4 6 4 3 MAINTENANCE OF SWITCH UNITS CASE MEMORY DIAGNOSIS FAILED IN SSC This case is similar to BP memory diagnosis failing Refer Section 6 4 1 6 Alarm Raised for AM CASE FAILED TO CONTACT AP This case is similar to BP diagnosis failing follow the same procedure given in 6 4 1 6 CASE MEMORY DIAGNOSIS FAILED IN AP Follow the same procedure as indicated for BP memory diagnosis failure Refer Section 6 4 1 6 Digital Trunk Links Going OOS for RSU This problem may arise due to a problem in the transmission media between RBM and parent exchange or due to fault in ESM card or ETS card First replace the ETS card 5 0 for DTK1 to DTK8 ETS 1 for DTK17 to DTK24 and put the TSC in service If the digital links come in service mark the ETS card as faulty If the links still do not come in service replace the corresponding ESM card Bus 0 for DTK1 to DTK8 Bus 1 for DTK17 to DTK24 make the ESM in service If the DTKs come in service mark the ESM
140. he trunks ix If the answering circuit test passes on the other trunk groups but is failing only on the trunks in a trunk group then check whether calls are otherwise successful in that If they are then the answering circuit tone sender at the distant end can be suspected x If the calls are also not going through on the TGP then cable might have gone faulty Inform the outdoor personnel C DOT DSS MAX MAINTENANCE OF LINES TRUNKS amp SERVICE CIRCUITS 7 1 2 4 3 EXCHANGE SIDE ROUTINING FAILED FOR DIGITAL TRUNKS i This section applies for failure in routining for digital trunks test sets 401 to 404 ii If test fails again run TST TRML CARD test set 401 and if it fails replace DTS card iii Run TST TRML CARD test set 402 and if it fails replace DTC card iv If the above steps do not solve the problem interchange TUC and try again Thus a possibly faulty TUC can be sensed v When bringing in service any new digital trunk DTS DTC Card perform TST TRML CARD PUT TRML CARD INS first with one TUC active and then with the other 7 1 2 5 Procedure for Handling Line Routining Abandoned Report In the routining abandoned report the reason for abandoning the routining is given If the reason for abandoning the routining is i TERMINAL BUSY then there is no need for any action to be taken by the operator ii This error message can come when TTC is out of service for any reason In such case t
141. here will be alarm raised for TTC The operator needs to first attend the TTC alarm After the TTC is repaired the routining can be resumed iii TST BUS BUSY this is similar to the above case Only difference is that the test bus was busy due to line or trunk testing being conducted at that time Operator need not take any action on this report Only thing is that periodic routining of lines should be normally performed at night when there is no other load on TTC iv TST BUS FAULTY this error message comes when TTC finds some voltage on the test bus This can happen if TA bus of any termination is permanently operated v TSTCKT NOTOK Before conducting test on any terminal the TTC does self test on itself If this fail then the above message is flashed Operator needs repeat the test to check whether the problem is persistent in which case the TTC needs to be replaced vi SYS RECOVERY MSG PARAM ERROR DEF CHK FAIL this normally indicates some software problem Confirm whether the problem is still persisting If it is report to support centre MAINTENANCE PROCEDURES 125 Chapter 7 7 1 2 6 7 1 8 7 1 8 1 7 1 8 2 7 1 3 3 126 Procedure for Handling Trunk Routining Abandoned Report The same error messages as that for lines can come for trunks also Besides the above error conditions some more error conditions are possible for trunks i TRK NOTAVBL This message is flashed if TST TRM is given for cond
142. hese messages are sent to the Central Message Switch CMS The CMS sends these messages to the Space Switch Controller SSC on a 128 kbps link to control space switching based upon this information Four 512 channel buses from four BMs are multiplexed to form a 2048 channel 16 Mbps multiplexed BUS which is sent to both copies of the Space Switch Switch Card Space switching of these 2048 channels is done based upon the switching information received by Space Switch Controller SSC from CMS Clock Distribution Fig 3 5 Please refer Fig 8 1 CM provides the central clock for distribution to the Base Modules The 8MHz clock may be locally generated at the Central Clock CCK card in case of CM XL and of Space Switch Clock SCK card in case of CM L by using high stability VCXO crystal or may be derived from an external reference clock using the Network Synchronisation Controller NSC card in case of CM XL and Network Synchronisation Equipment NSE in case CM L under the control of SSC In the event of failure of external reference or duplex failure of the NSC cards NSE the local clock is fed in the holdover mode synchronised to last reference value In any arrangement the local or external clock is distributed via Central Bus Extender CBX cards in case of CM XL The CBX card provides an interface between SSC and SSU SSC makes any switch card access through CBX CBX also handles any power supply errors in SSU and BTU Each CCK CBX NSC c
143. ices Due to intelligent protocol implementation in conformance to ITU T specifications and with the implementation of CCS7 signalling in C DOT DSS it has been made possible to provide the value added services Also it is possible to configure the C DOT DSS as TAX with multiple nodes connected on CCS7 signalling ISDN Services are the most widely used carriers to transport bulk volume of data With the increasing use of Internet Access the use of ISDN interface is likely to go up as it provides the reliable access to the user at the rate of 64 128 Kbps In addition to reliable data connection at higher rate it integrates computer and Telephone on the single access In C DOT DSS the implementation is through add on modules to provide the services in the beginning itself or retrofit as and when required This facilitates the network administrator to upgrade the already commissioned exchanges in future REDUNDANCY To meet the stringent availability requirements C DOT DSS employs hot standby technique for all processor complexes so that in the event of the failure of any one security block not more than 8 subscribers will be affected Hardware cross links between processors have been planned in such a way that even the failure of two dissimilar processors will not affect system performance Also wherever there is no duplication of hardware units multiple units are provided to work in a load sharing mode In the event of failure of one of th
144. inal Test Controller TTC for testing of analog terminations Power Supply Unit PSU I provides logical voltages and ringing current in the ATU Analog Subscriber Line Cards Two variants of subscriber line cards as LCC or CCM with interfaces upto 8 subscribers provide basic BORSCHT functions for each line Analog to digital conversion is done by per channel CODEC according to A law of Pulse Code Modulation Each CCM card has the provision of battery reversal for all the 8 lines with the last two lines having provision to generate 16 KHz metering pulses to be sent to subscriber s metering equipment The 8 bit digital voice output of four LCCs is multiplexed to form a 32 channel 2 Mbps PCM link also called a terminal group TG Since a Terminal Unit has a maximum of 16 terminal cards there are four such terminal groups The signalling information is separated by a scan drive logic circuit and is sent to the signalling processor on four different scan drive signals The LCC CCM also provides test access relay to isolate the exchange side and line side to test it separately by using the Terminal Test Controller TTC Analog Trunk Cards Analog trunk cards interface analog inter exchange trunks which may be of three types as TWT EMT and EMF These interfaces are similar to Subscriber Line Card with only difference that the interfaces are designed to scan drive events on the trunks as per predefined signalling requirement 16 C DOT DS
145. including MFC remain inservice then it is SCIC that was faulty and the repair is successful If the problem persists inspite of all this check the backplane of the MFC and SCIC However this is not recommended in case of a functional BM and should be attempted only in BMs being installed SOME MF CIRCUITS HAVE GONE FAULTY IN THE SYSTEM i Check the alarm on the ADP VDU and Printer Identify the entity DTMF MF SENDER MF RECEIVER for which the alarm is raised ii Check the status of all the MFCs using DISPL SWU ALL command and verify that all the MFCs that are equipped are inservice If one of the MFCs is OOS then refer procedure as explained for previous case a iii Using DISPL SRV STATUS command check the status of the MFC on which routining had failed on some or all circuits The status of those circuits will be OOS SE iv Repeat test on the MFC TST SRV test set 301 after giving reset and confirm the fault v Put the MFC out of service jack out the card jack it back in again give it a reset and bring it inservice again Repeat the test on it again vi If now the test passes on all the circuit then problem is of transient nature Keep the MFC under observation for few days Threshold Alarm for Lines Indication LED flashing on ADP accompanied by an audio alarm The total no of lines faulty will also be indicated on the ADP Depending on the no of lines faulty the alarm will be Non urgent Urgent or Cr
146. ine If closed loop tests indicate fault in the telephone instrument then telephone has to be replaced C DOT DSS MAX MAINTENANCE OF LINES TRUNKS amp SERVICE CIRCUITS ii Perform exchange side tests and confirm that there is no fault at the exchange side If there is fault at the exchange side then the concerned line card should be replaced iv If the subscriber has changed his instrument recently check whether he is now using the DTMF phone Check the data for proper instrument type and modify the instrument type if necessary 7 2 5 Speech Quality Poor i Presence of foreign potential and low insulation may be the causes of poor speech quality ii Perform outside plant open loop tests on the subscriber If the tests indicate fault in the cabling it has to be traced and rectified iii Conduct exchange side tests also and confirm that there is no fault at the exchange side If there is fault at the exchange side then the concerned line card should be replaced iv Make check on other lines in the same TU 7 2 6 Feeble Speech i The likely cause of this complaint is lower values of loop current This can be confirmed by conducting closed loop tests on the line ii Conduct exchange side tests also and confirm that there is no fault at the exchange side If there is fault at the exchange side then the concerned line card should be replaced 1 2 1 Call Being Routed Wrong Numbers i In this case most likely the
147. intenance of IFC cards in BTU 0 1 All Switch Multiplexer cards have to be diagnosed at least once ina week IFCs should be made OOS one at a time and diagnosed and made inservice Before making any IFC OOS ensure that all BMs are in duplex The diagnosis should be carried out only during lean hours Routine Maintenance of SSU 0 1 amp SSCU Hardware The general procedure for routine maintenance of duplex units given in sec 5 3 1 1 can be followed Here duplex units to be considered are SSC 0 1 MU 0 1 and SS 0 1 Each Space Switch SS plane consists of all switch cards SWC1 to SWC16 SSBID and CLK and diagnosis of SS includes diagnosis of all these cards of the copy If NSC card is equipped card id of CLK indicates to NSC If it is not equipped then card id of CLK indicates to CCK Routine Maintenance of Alarm Display Panel ADP SM ADP MM Once in a day run the LED test on ADP by pressing the LED Test button mounted on its front panel Routine Maintenance of Fan Failure Detection Unit Fan failure detection unit mounted on top hat of the CM XL cabinet for cooling purposes is to be monitored every day for proper functioning of all fans Generally alarm on FBI mounted on corresponding suite where CM XL is installed is raised in case of blown fuse on any Filter Box mounted in CM XL cabinet or blown fuse in FFD cards or any fan being stuck on top hat or the CM XL cabinet MAINTENANCE PROCEDURES 75 Chapter 5 5 5 5 6 5
148. ircuit i e not associated with DIRNO of the same BRL card or any other BRL card in the ISTU After executing the command the TLC is created and subjected to functional tests by using the TST TEN as reference circuit Once the functional tests are executed and passed the status of the circuit is marked as INS FREE which can be verified using command DISPL TRM STAUS In case of failure the status of the circuit is marked as OOS SE In such cases it is advised to delete the TLC and recreate it after changing the BRL Card Alternatively it is possible to create the TLC on any alternative BRL Card PROCEDURE TO DELETE A TLC The TLC can be deleted using CRP Command DEL TST CKT with parameters as TLC TEN The mandatory requirement for deleting the test circuit is that the BRL Card should be made OOS OPR using CRP Command FRC TRML CARD OOS PROCEDURE FOR TESTING OF ISDN TERMINATION CARD In case more than 50 interfaces corresponding to a Interface Card is reported as faulty it is advised to perform the tests on the BRL PRL Card The card can be tested using CRP Command TST TRML CARD with parameters as RTN COD TML CRD TYP BRI PRI TST SET 605 606 CARD SLOT C DOT DSS MAX 5 8 2 6 5 3 3 5 3 3 1 5 3 3 2 ROUTINE MAINTENANCE The status of the BRL Card can be displayed by using CRP Command DISPL TRML CARD STATUS with parameter TML CRD TYP BRI
149. is attempted to be brought INS when the mate Switch plane is OOS the request is rejected with reason CONFIG_NOT_SUITABLE 4 When the first network clock has to be brought INS the SEL CLK SRC command should be used If FRC NSC CLK INS is used it will be rejected with result CONFIG_NOT_SUITABLE Output The result of the command is shown as SUCCESS if the clock source could be brought INS The status awarded could be INS_TOBE INS_COLD also Sample report CLOCK SOURCE DIAGNOSIS REPORT RESULT PASS UNITID NSC 1 CLOCK SOURCE NEW STATUS INS TOBE OLD STATUS OOS OPR C DOT DSS MAX MAINTENANCE PROCEDURE FOR NETWORK SYNCHRONIZATION If the clock source is not available to the NSC then the result displayed is FAILURE Sample report CLOCK SOURCE STATUS CHANGE REPORT UNIT ID NSC 1 CLOCK SOURCE RCLK2 RESULT FAIL NEW STATUS OOS SUS OLD STATUS OOS OPR If the execution of command itself fails the result shown is INVALID CHANGE CONFIG NOT SUITABLE Sample report CLOCK SOURCE DIAGNOSIS REPORT UNIT ID NSC 1 CLOCK SOURCE RCLK2 RESULT INVALID CHANGE NEW STATUS INS TOBE OLD STATUS INS TOBE 8 6 1 4 PUT NSC CLK OOS Put NSC Clock Out Of Service Function To let the operator throw out a particular clock source of NSC which is not the selected clock source Input parameters 1 NSC ID Possible values 1 NSC 0 2 NSC 1 2 CLOCK Possible values 1 RCLKO 2 RCLKI 3 RCLK2 4 USRN 5 D
150. it available to the system AUD LOCK This audit checks that the area that should be locked is locked If it is not then it is locked AUD CLEAR This audit involves sending to all the eternal processes a Maintenance Clear message so that they recreate themselves and in the process release all resources inadvertently held by them AUD TM The terminal maintenance audit has been designed to maintain consistency of various counts maintained by GFRH The audit runs for all entities trunks lines etc except when invoked by roll back rec routine in which case it runs on the particular entity on which GFRH encountered an error The audit is triggered by 1 AP Boot 2 GFRH roll back rec routine 3 Operator 4 Idle time AUD UNIT STATUS This audit involves comparing the status map of all the units of the BM as maintained by BMCM against that maintained by the units In case of a discrepancy or wrong status being present at either end it tries to correct it If it is unable to correct it it sends a message to BMCM to this effect AUD ETRNL Involves getting the eternal process identities from the peripheral units including BMs which were supplied to it at the time of initialisation If some unit sends a wrong eternal process identity it is supplied with the correct identity MAINTENANCE PROCEDURES 167 Appendix B 15 AUD STALONE CCM STATUS This involves comparing the unit status map maintained by BMCM with the
151. itical The same alarm would be available on VDU OOD and Printer also Threshold values for lines can be seen from system parameters Procedure C DOT DSS MAX MAINTENANCE OF LINES TRUNKS amp SERVICE CIRCUITS Threshold alarm for lines get raised when a large number of lines go OOS or This section gives the procedure for handling conditions wherein suddenly lots of lines go faulty in a short period of time If on the other hand if individual lines go out of service one after another and this leads to a threshold alarm for lines then refer the procedure given under section for handling subscriber complaints or System reports If the lines have all gone OOS SE then follow procedure 7 1 1 2 1 CASE LOT OF LINES HAVE GONE OOS SE SUDDENLY Procedure i Look for some Line Status Change reports on printer or in OOD LOG just prior to alarm for lines From the reports check that several lines have gone OOS SE suddenly ii Cross check the status of some of these lines through MMC commands iii Try to bring some of these lines into service through put inservice or force inservice commands If they come inservice then make calls on these lines and check that everything is proper iv On the other hand if the lines fail to come inservice do as follows Check whether all the lines belong to same TU or they are distributed over different TUs v If they are belonging to the same TU the fault should in the active TIC SP path Inte
152. k test 2 Origination Test Digit Reception Test Flash Test Disconnection Test Answer Test Ringing Test 0 10 Ring Trip Test 10 Reversal Detection 11 Codec Analog to Digital Test 12 Codec Digital to Analog Test Time Estimate 40 secs Test Set No 104 Exchange Side Tests on Lines Signalling Line Circuit Current Limiting Circuitry Check test 1 Line Circuit Current Limiting Circuitry Check test 2 Origination Test Digit Reception Test Flash Test Disconnection Test Answer Test Ringing Test OANA Ring Trip Test 10 Reversal Detection Time Estimate 30 secs Test Set No 105 Exchange Side Tests on Lines Codec 1 Codec Analog to Digital Test 2 Codec Digital to Analog Test Time Estimate 10 secs Test Set No 106 Outside Plant Open Loop Exchange Side Tests on Lines Signalling Codec C DOT DSS MAX TEST SETS Interference Voltage Test Insulation Resistance Test Capacitance Test including instrument capacitance Line circuit current limiting circuitry check test 1 Line circuit current limiting circuitry check test 2 Origination Test Digit Reception Test Flash Test m ge cp ode gt ge Ge Disconnection Test 10 Answer Test 11 Ringing Test 12 Ring Trip Test 13 Reversal Check 14 Codec Analog to Digital Test 15 Codec Digital to Analog Test Time Estimate 160 secs 6 Test Set No 107 Closed loop Tests on line
153. l a condition is obtained when putting the TA bus cable of a particular frame causes the diagnosis to fail That frame is identified as faulty frame v After the faulty frame is identified put back the TA bus cable of that TU Jack out the termination cards in that frame one by one and repeat the diagnosis till it passes after the jackout of a particular card Mark that card put TTC in service Connect TA bus cables of all frames and make C DOT DSS MAX 6 4 1 11 6 4 1 11 1 6 4 2 6 4 2 1 6 4 2 1 1 6 4 2 1 2 MAINTENANCE OF SWITCH UNITS all lines trunks which had gone out of service due to jack out of cards in service Alarm Raised for ANNC CASE FAILED TO CONTACT TO TOGC i Follow the general procedure ii If the problem continues interchange the TICs in that TU and try to bring the ANNC inservice If now the ANNC comes inservice then it is the now standby TIC that is faulty Replace the TIC and make it the active copy and check that the ANNC remains inservice iv If on the other hand even after interchanging the TICs the ANNC does not come inservice then interchange the BMS and try bringing it inservice If it comes inservice then it may be the BMS current standby which is faulty Inter change of SCIC can also be tried in case of problem persisting iii v Put the BMS out of service and diagnose it If diagnostics fail refer section on BMS faults vi Test all the announcements on ANNC c
154. ling links is used as processor in CCS7 Signalling Unit For more than 32 signalling links but upto 64 signalling links only HPC is to be used as processor iv case of 800K BHCA configurations HMS is used in all the BMs HMS and MSC MSD are not pin to pin compatible and can not be used interchangeably v While changing any TUI card proper jumper settings as mentioned in Installation Document should be ensured The same is valid for BME cards used in CCS7 signalling unit SUM with HPC Otherwise it is same for BM AM CM and SUM with BPC vi While changing any Processor Card in BM CM amp AM the jumper settings and EPROM status should be ensured At the time of changing any controller card from some other site PROMs of correct software version should be ensured before jacking the card into the system 10 3 2 Known O amp M Changes as a Result of Feature Enhancements i A subscriber data can be modified only after making it OOS OPR ii It is not possible to delete the subscriber in growth mode 154 C DOT DSS MAX DO S AND DON TS OF MAINTENANCE i the Hunt Group related CRP commands are possible only when IOP is ONLINE iv Due to enhanced disk partitioning to utilise the full capacity of the disk the boot up time for IOP has been increased to 30 minutes or even more depending upon the IOP and disk types used It is not possible to go to growth mode when IOPs are in DUPLEX
155. me INS unless compatible software EPROM is not used 10 2 6 Mandatory Execution of MOD DAY TYP It should be ensured that in 1 week of January amp July of every year command is executed to define the day type 10 2 7 Programming for Routing of Priority Subscriber s Call In all the routes priority 2 should be allowed by defining the trunk group choice against priority 2 MAINTENANCE PROCEDURES 153 Chapter 10 10 3 ROUTINE OPERATIONAL AND MAINTENANCE PRECAUTIONS In addition to critical DO s and DON T s some more precautions are to be taken to avoid any problem during O amp M functions 10 3 1 Precautions to be Taken While Handling Various Hardware Cards i With the introduction of Distinctive Ringing in C DOT DSS there are two different versions of PSU used in Analog Terminal Unit One with blinking ringler LED to indicate the ringing cadence which is used at the existing sites The modified PSU is identified with continuous ringer LED and used only at the sites where Distinctive Ringing feature is offered The two PSUs can not be used interchangeably Also in one exchange only one version of Power Supply can be used i e with distinctive ringers or without distinctive ringing ii The SHM cards cannot be used interchangeably with BPC and HPC in SUM To use SHM cards at the sites where HPC has been used as processor in SUM in the form of firmware changes is mandatory on SHM cards ii For 32 signal
156. me of the user commands and precautions should be taken in day to day operations of the exchange 10 2 DO S AND DON TS A number of basic operation and maintenance guidelines are listed which should be carefully studied followed during day to day operations 10 2 1 10 2 2 152 Restoration of BMDC The BMDC cartridge should never be restored in day to day operation Restoration of BMDC is required only when complete software is being loaded in the exchange The restoration of ed backup does not require restoration of BMDC In case of data corruption when restoration of old exchange data is required only ed backup restoration using command COPY IN is sufficient As and when BMDC has been restored in working exchange ed as well bd must be copied Get around is given in Annexure D to recover the exchange in case of failure Programming Trunk Groups in C DOT DSS Keeping in view the complexity of the network and multiple features being supported the software release for different configurations applications of C DOT DSS the following requirements should be met at the time of creating a trunk group e All the incoming trunk groups from TAX or ILT should be programmed as TTAX e All the incoming trunk groups from the parented exchanges should be defined as ORD C DOT DSS MAX DO S AND DON TS OF MAINTENANCE e If C DOT DSS is configured as TAX ILT all the O G trunks should be defined as
157. n 4 1 concentration each BM can grow upto three racks Each rack consists of 6 frames and each frame consists of 26 card slots CM and AM are however housed in the same rack Thus a card slot is uniquely identified by a combination of the four fields Field 1 Base Module Number 1 to 32 This field indicates BM Number in which the circuit is located Field 2 Rack Number within a Base Module 1 to 3 This field helps in identifying the particular rack of the specified BM in which circuit is located Field 3 Frame Number within a rack 1 to 6 This field helps in locating the relevant frame in the rack Field 4 Card Slot Number within a frame 1 to 26 This field helps in locating the card slot in which the circuit resides Field 5 Circuit No It identifies 1 out of 8 circuits for Lines Analog trunks 1 out of 16 service circuits of 1 out of 32 tone circuits or digital trunk channel 42 C DOT DSS MAX HARDWARE ARCHITECTURE Z3WdWIXIANdIW DCXVIANDCXVIANXVINSSQNDIS3QN S39NVHOX3 AO LOQ O 3IN3HOS MIIA 1015 ttt avs No1109 6 T ovu dO m LMOVH 43 MAINTENANCE PROCEDURES Chapter 3 44 3 10 1 TERMINAL EQUIPMENT NUMBER TEN TO PHYSICAL LOCATION TRANSLATION TEN uniquely identifies a subscriber port trunk circuit service circuit TEN consists of five fi
158. n logging down the problem occurrence and the corrective action taken by the system C DOT DSS MAX 6 4 4 1 1 MAINTENANCE OF SWITCH UNITS Only way the operator can help is stop all activities on the system that are not critical at that time 1 li iv Stop periodic routining of switch units lines trunks if they are going on at that time do not issue any man machine commands other than that which is absolutely necessary stop any repair action other than that which is very essential like both copies of a duplex unit has become OOS etc Check if too many status change reports are coming for any set of terminals repeatedly on OOD If they are then make those terminals OOS OPR Check the status of switch units If any unit is repeatedly going OOS and coming inservice then make it OOS OPR Check whether too many entities subscriber trunk group etc are put under observation If they are then remove them from observation Check whether some of the MF circuits have gone faulty causing repeated call attempts Overload of Memory Resources Buffers Stack etc This kind of overload normally occurs due to some abnormality in the behaviour of the system under some specific conditions The system has its own built in mechanisms to control this type of overload but following actions are recommended 1 iii iv Stop periodic routining of switch units lines trunks if they are going on at th
159. n the last of the four positions of the corresponding IFC card slot B connector Note The above fault message can appear even if the BusO sync and 1 sync are not coming to the TSU These signals come through the BM CM data cable which also needs to be checked This type of fault is effected only at the time of installation and capacity expansion C DOT DSS MAX 6 4 1 2 4 6 4 1 2 5 6 4 1 2 6 MAINTENANCE OF SWITCH UNITS CASE MATE WATCHDOG TEST FAILED Explanation i The software indicates to the active TSC to stop punching its watchdog As a result of this the WD output line of active TSC will go high This will be sensed at the input of the OOS OPR TSC and reported to the BP ii The same is repeated by stopping the punching of watchdog in the OOS OPR TSC and detecting at active TSC and reporting to BP Action TSC which fails in diagnostics could be faulty or the active TSC could be faulty with the same probability Hence TSC which is OOS OPR should be changed first If problem persists force this TSC in service and replace the copy TSC Note This should be done only after ensuring that the card which fails in diagnostics has no other problem except WD problem Else this procedure could be dangerous CASE TSC TIC LINK TEST FAILED Explanation This kind of message appears usually when TSC is OOS OPR and is getting diagnosed and all the TICs which are tuned to this TSC are in OOS EXT state
160. n the system Conceptual aspects of trouble fixing are covered in first two sections section is devoted to various phases of trouble fixing Detection of fault symptoms their analysis and corrective actions are discussed here Importance of information field viz fault code fault probability action code existing in the reports output by the system is emphasised Detailed procedures for fixing troubles are however presented in the last section This section is structured according to the fault symptom which could be alarm on ADP user complaint failure of a confidence check or some observation pointing towards system s misbehavior TROUBLE FIXING Trouble fixing involves the following three phases 1 Knowing symptoms ii Analysis of symptoms 11 Corrective action Each of the above phase is described below Knowing Symptoms This involves collecting the desired information which when analysed points towards the type of corrective actions to be taken The information can be acquired from the Alarm Display Panel ADP cyclic alarm display on Output Outside Dialogue OOD terminal diagnostic reports output by the system and routine maintenance checks MAINTENANCE PROCEDURES 77 Chapter 6 78 The above aspects are briefly described below Alarm Display Panel ADP 1 11 Alarms are indicated through audio visual means on this panel and examination of ADP reveals the following aspects a b c d
161. ne on top hat of the CM XL cabinet These fans intake hot air raising through the CM frames and thereby providing additional cooling effect to CM XL cards C DOT DSS MAX HARDWARE ARCHITECTURE dd dWTXINNaW DCXVIAN DCXVIANXVINSSQNDDIS3Q A I8IN3SSV LINN NOILLO3 L3Q SYNTIVA 1834 0844 1034 034 1034 sr vr i 80 90 v0 20 2 LENA 60 N4 10 S0 0 L0 47 MAINTENANCE PROCEDURES Chapter 4 System Initialisation amp IOP Maintenance Procedure GENERAL The System Initialization is the process to bring up the system from cold level to provide the service It loads the code patches amp data It initializes the entire system to a level in which calls are processed to provide service During initialisation if at any time the system faces a unrecoverable software hardware problems it will try to solve the same by going for higher level recoveries LEVELS OF INITIALISATION FOR SYSTEM MODULES There are many levels of initialisation The different levels of initialization are described below Power On This will occur when the power to Administrative Processor AP Base Processor is switched on In this case BPs will go for power on tests After the tests pass it will try to
162. nks One set of Digital Trunk Synchronization DTS card alongwith the Digital Trunk Controller DTC card is used to provide one E 1 interface Each C DOT DSS MAX 3 2 3 3 2 4 3 2 5 HARDWARE ARCHITECTURE interface occupies one TG of 32 channels and four such interfaces share 4 TGs in a Digital Terminal Unit The functions performed by TIC and SP in Analog Terminal Unit are collectively performed by the Terminal Unit Controller TUC in the Digital Terminal Unit The scan functions are HDB3 to NRZ code conversion frame alignment and reconstitution of the received frame The drive functions include insertion of frame alignment pattern and alignment information Each interface can be configured as CAS or CCS interface SS Signalling Unit Module SUM Any one of the ATU or DTU in a BM can be replaced by SUM frame to support CCS7 signalling Only one such unit is equipped in the exchange irrespective of its configuration or capacity For details of SUM architecture refer to chapter no 4 of C DOT DSS MAX General Description ISDN Terminal Unit ISTU One of the four ATUs DTUs in a BM can be replaced by ISTU to provide BRI PRI interfaces in C DOT DSS The only constraint is that ISTU has to be principal TU i e directly connected to TSU on 8 Mbps PCM link The ATU DTU cannot be used in concentration with ISTU By equipping one ISTU in the exchange a max of 256 B channels are available to the administrator which can be c
163. nment Register Note down the voltage and current reading of the power plant after every hour Similarly log the temperature of the switch room every hour Input 3 phase voltage should also be logged xiii Spare Card inventory Register This contains the details of spare cards available in the exchange One page can be reserved for each type of card LCC TIC ISP etc Details on spare cards available sent for repair etc are entered in this book The following details should be available card serial no on date on which card sent for repair date on which card received after repair date on which card is put in the system after it is put as a replacement slot in which the card is put in the system Remarks FILES Correspondence Files i 11 iii Subscriber Feedback File This file contains the feedback form duly filled by the subscribers PCO Meter Reading Record This file contains the record of meter reading of PCOs given to J E s from time to time Correspondence with Other Exchange This file contains all the letters issued or received from or to other exchanges MAINTENANCE PROCEDURES 149 Chapter 9 9 4 9 5 150 iv OCR File The record of opening and closing of subscribers is kept in this file The letters received for opening closing of subscribers is kept in this file v FDT Installation The forms sent with FDTs are kept in this file vi MRC File This file contains all the letters issued
164. ns occurring frequently Reports output by the system are described in a separate manual titled C DOT DSS MAX Maintenance Alarms and Reports However the reports are summarised below Switch unit diagnostics abandoned report Switch unit diagnostics failed report Overload report Answering circuit test failure report Process recovery report Load pass report 0 Status change report for terminals to OOS without test details C DOT DSS MAX MAINTENANCE OF SWITCH UNITS Detailed report on routining done Brief report on routining abandoned for terminals Brief test passed report for terminals Switch alarm report Overload alarm report Threshold crossover alarm report Power or battery alarms IOP synchronization report HF Killer trunks and service circuits report vi Remote Alarms Monitoring The operator can find out the severity of the alarms in the system by this remote alarms features In alarm monitoring feature the operator can dial a number which is DIR TYP alarm monitoring ALM MON and find out the alarm type in the system The tone fed is as follows Alarm type Tone Fed Non urgent Very slow interrupted tone Urgent Slow interrupted tone Critical Fast interrupted tone Normal Continuous tone 6 2 2 Corrective Action Corrective action could be one or more than one of the following activities a Replacing a circuit board b Correcting a human mistake such as a switch unit made O
165. ogether For example the interchange command for BP might get rejected altogether because the standby BP is not able to access either of the memories when made active and hence the original BP is retained as the active copy and the standby copy is made suspect ii Now in the above case if diagnosis on BP fails and is declared OOS SYS then follow the same procedure as when BP alarm is raised iii If on the other hand diagnosis passes then make one of the MU OOS OPR and diagnose it Thus the interface between the suspected BP and MU gets tested and the fault will come out Follow the procedure given for handling Alarms and Diagnostics Failed Report Procedure for Handling System Integrity Reports Audit Failure Report 1 If an audit fail report has come in isolation then just repeat the same audit manually and check whether it passes now If it passes then whatever inconsistency that was present is now cleared Check for reoccurrence of the audit failure and report to support centre if it repeats If the audit fails again it means that the audit is detecting some inconsistency in the system but is unable to clear it by itself Try running the associated audits and then the same audit again Check whether it passes now If it does not check how the service is getting affected because of this problem If it is seriously getting affected then reboot the system INIT SYS STABLE CLEAR Otherwise inform the support cen
166. omplex form a security block i e cannot be used with CCK1 Thus there is a copy 0 complex and a copy 1 complex The CBX also synchronises all SSC accesses to SSU with the 16 MHz clock as well as BTU MAINTENANCE PROCEDURES 23 Chapter 3 IN8 edI Ned W XVIAN DCXVIANXVINSSQWNDIS3QN 51214 WO OL 51216 AINGOW 3SV8 H3TTOHLNOO HOLIMS SWIL OSL LOTS INIL 9 LINN 058300 ASVA HOLIMS INIL SL H3110H1NOO TVNINH3L OIL TVNIWH3L IL HOLVH3N39 3NOL VOL WNINYAL 91 HOSS30OHd SNITIVNSIS dS H3TIOHLNOO 5 2108 106 HOLIMS 39VSS3NW LOHIA MINIT GSHOLIMS 51 2 LINN IYNINY3L 45 d 2106 a L SLINDYID AW 5 5179 61821 051 s 4 ol LE 81821 VOL S3NI1X8d ee E gt 899 v gt lt 818 2 e L 7 OL 51821 5122 gt LINN HOLIMS ANIL C DOT DSS MAX 24 HARDWARE ARCHITECTURE O9SS ecdWedIW XVIAN DCXVIANXVINSSQNWNDSIS3QN d3TlOH LNOO HOLIMS 3 HOLIMS 5 76
167. on rt e or Fe eve ra ee 82 6 5 Procedure for Handling Systems Reports esses enne nennen ns 112 6 6 Transient Fault Handling s cie rv t Ced Co eoo Oe 115 Maintenance of Lines Trunks amp Service 117 7 1 Threshold Alarms amp Routine Maintenance Complaints 117 7 2 Procedure for Handling Subscriber 127 Maintenance Procedure for Network Synchronization 4 131 B T IntFodUt DOR oos e ie rir ieu x rdc alana Na edem n ce area 131 8 2 Position of NSC Card in the System 133 8 3 Function of the Card iie Re 133 8 4 Duplication and Security Block eite tI teer 133 8 5 Diagnostic Features dete ua eA dete E TRE 133 8 0 Error REPORTE oie eo FER vita vrai Pha E ed Pre uev Ed 134 8 6 Dos and for NSC ii EMPIRE UHR GERM 143 8 9 Alarm Sttategy for NSC 144 5 10 Man Machine Interface otto te ERES ax eU ra euo EES 145 B 11 Modes Gf Operation 145 Chapter 9 Chapter 10 Appendix A Appendix B Appendix C Appendix D Appendix E Loes To MOUTH ecce
168. one maintained by CCM If there is a discrepancy between them the data structure with a valid status is believed and the other is corrected If both the data structures have valid values the BMCM data structure is believed and CCM data structure is corrected In this case to ensure that the right decision has been taken the AUD UNIT STATUS audit is initiated The audit however avoids auditing the status of the units whose present status in mbc bm unit is CCS EXT RECENTLY 16 AUD SANITY The audit of the sanity map MSM MODULE SANITY MAP is for validating the list of units from which a sanity punch is expected and the list of units from which the sanity punch is not expected It involves consulting the status map maintained by BMCM mbc bm unit If there is a conflict between an entry in the status map and one in the sanity map the status map is believed to be correct and the sanity map is corrected accordingly 17 AUD COUP This audit involves determining whether a TP or a CMR existing in the BP has a right to be present in the system If it shouldn t be present in the system it is sent a maintenance clear It involves determining that in the particular phase of the call it is in communication with the processes that it should be and that it has not been in that phase of the call for a duration greater than the allowed duration and it is present it is sent a maintenance clear or deleted straight away depending on the situation
169. onfigured as BRI PRI or any mix as per site requirement Depending on the requirement of number of ISDN Interfaces one or more ISTUs can be integrated in C DOT DSS either in one BM or distributed across different BMs For details refer chapter no 4 of C DOT DSS MAX General Description Time Switch Unit TSU Time Switch Unit TSU implements three basic functions as time switching within the Base Module routing of control messages within the Base Module and across Base Modules and support services like MF DTMF circuits answering circuits tones etc These functions are performed by three different functional units integrated as time switch unit in a single frame refer Fig 3 2 MAINTENANCE PROCEDURES 19 Chapter 3 fISL edWNedIA XVIANDCXVIANXVINSSQNDSIS3QN H3TIOHLINOO HOLIMS AWIL OSL 1015 AWIL 9 SNIH3MSNV HOLVH3N3O 3NOL VOL H3TIOHLNOO JOVAYALNI SLINDYID 39IAH3S DIOS H3TIOHLNOO AONSNDAYS AONSNDAYS OA HOLIMS 39VSS3I 3SV8 SINg LINN HOLIMS AWIL t TIVHIN3O OL SXNI1INOd S ZLS 251 MINIT 193410 v9 3ON3H3HNOO jj ANIT INOd 99 42 51 ZE NI WOd Sdqy 8 s 821 i c 24N sdqwz 51 22 2 0105 gt i s 22 VO
170. or received regarding meter reading of subscribers to operating company The exchange billing letters are also kept in the same file vii Manuals Equipment File A file containing the list of manuals documents available at the exchange and also the test equipments available at the exchange REPORTS Following maintenance reports have to be generated from the exchange Weekly and monthly exchange performance report monthly report H W cards faulty and S W downtime failure e Faulty junction report monthly Subscriber complaint analysis report monthly MANUALS REQUIRED The following manuals are at least needed in the exchange i Power plant manual FR SWC inverters ii Backplane wiring details of all mother boards amp cards of the system iii Administration and maintenance commands manual iv System general description manual v Printer manual vi System error codes manual vii Exchange operations manual C DOT DSS MAX LOGS MAINTAIN viii Maintenance Procedure Manual ix Installation manual x SW release document corresponding to the current SW installed in the exchange MAINTENANCE PROCEDURES 151 Chapter 10 Do s and Don ts of Maintenance 10 1 GENERAL This software release has been generated and being released to field after field trails are successfully completed The release supports most of the requirements raised from time to time This has resulted in restructuring of so
171. ork Synchronization are implemented in C DOT DSS These are MAINTENANCE PROCEDURES 29 Chapter 3 3 6 1 30 i Locked Mode When one or more primary reference clocks are available NSC NSE enters into locked mode by selecting one of the available network clocks according to fixed priority and synchronises to it i Holdover Mode When NSC NSE loses the network clock to which it was locked and when no other network clocks are available it enters the holdover mode in which it synchronises to the last reference value iii Free Run Mode When none of the network reference clocks are available and no locking to external reference has taken place before In this mode system works on its local clock In C DOT 055 MAX Network Synchronisation Controller NSC Card synchronises the local clock of the exchange with the network clock It gets input clocks from digital trunks connected to higher level or same level exchanges It has an on board clock source It gives a network synchronised clock and SYNC signals to the duplicated Central Clock CCK The CCK is controlled by the SSC through CBX The clock card generates its own clock and can be configured to select between the local clock and two copies of NSC clock Each clock card distributes 16 MHz clock and 8 kHz SYNC to self SSU and 16 MHz clock to all Bus Termination Units BTUs which receive switched data buses from all the BMs connected to CM In case of SBM RAX and MAX L exchang
172. ou want to continue Y N Give Y and wait for INIT SINGLE USER MODE and prompt Now the IOP can be switched off IOP Boot Up Procedure Power up the IOP At the monitor prompt give the command VHC x x bo where x x is the current monitor version A file system check is automatically initiated In case any error is found in the root file system the system will correct the inconsistency and displays MAINTENANCE PROCEDURES 53 Chapter 4 Press the reset button and repeat the above procedure After the system boot up is completed The System will prompt for date Enter date in the format MMDDHHmmYYYY e g 102020301990 Oct 20 8 30 PM 1990 Date If the date entered is not correct the system will reject it with a message Bad Conversion If the date is correct then the operator will be asked to confirm it Once the operator confirms the date UNIX gets loaded Console Login Prompt will be displayed on the console and the Login Prompt will be displayed on other configured terminals 4 4 PROCEDURE TO BRING IOP INSERVICE FROM OOS STATE The maintenance personnel may need to bring an Out of Service IOP in service in two distinct cases namely When one is active and other is in warm start level When both the IOPs are out of service and the DSS is functioning without an IOP Both cases will be discussed in detail 4 4 1 54 One IOP is INS ACT Before the OOS IOP is brough
173. ouncement circuit dialled e g if 1 1 1 3 is the card slot number of ANNC then corresponding announcements are numbered 01110301 to 01110308 Service code for DBE In case of DTMF telephone 683 TEN can also be used in place of 1683 TEN for faster response For further information on DBE feature refer to document C DOT DSS MAX Subscriber Features amp Supplementary Service Procedure for Testing of TTC Check the sanity of TTC against a good line in the switch room Give TST TRM with test set 103 and check that it passes Conduct test set 102 with the detailed parameter options and check that values measured are appropriate Refer Appendix D for limits of TTC measurements C DOT DSS MAX ROUTINE MAINTENANCE 4 ROUTINE MAINTENANCE OF CENTRAL MODULE CM AND 5 4 5 4 1 5 4 2 5 4 3 5 4 4 5 4 5 5 4 6 ADMINISTRATIVE MODULE AM This involves maintenance of APU hardware SSCU hardware SSU hardware and BTU hardware Routine Maintenance of AP Complex The general procedure to be followed for routine maintenance of duplex units 5 3 1 1 can be followed Routine Maintenance of CMSs CMSs have to be diagnosed one by one during lean hour Before making any CMS out of service it should be ensured that TSC in all BMs are in duplex all other CMSs are in service and all IFCs are in service For diagnosing a CMS make the unit OOS OPR then diagnose and put force it inservice if it passes Routine Ma
174. r attending to the already detected faults the following test sets can be scheduled at low traffic hours using the TST TRM command for a range of lines Open loop outside plant tests Test set no 102 Exchange side line circuit tests Test set no 103 It is to be ensured that at least a few lines are tested in each frame every day Note For proper outside plant side tests for lines open loop and closed loop the line category for the subscriber line is to be assigned based on line characteristics The tests will be declared passed or failed depending on the category of the lines The various values for the test parameters corresponding to different categories are given in Appendix F and details of test sets are given in Appendix A Procedure for Testing of Analog Trunks i Each terminal circuit should get tested at least once in 24 hours First of all ensure that all trunks are in inservice using DISPL TRM ALL or DISPL TGP STATUS or DISPL TRCNT OOS command ii If there are some trunks OOS the operator should first test it by TST TRM and attend to the fault reported in TST TRM report ii The following test sets can be scheduled at low traffic hours using the TST TRM for a range of trunks or TST TGP for one trunk group at a time e Exchange side trunk circuit tests OG IC Test set no 202 e O G trunk answering circuit tests Test set no 203 iv Answering circuit test can be performed on outgoing trunks only C DOT
175. r from top in the same module cabinet BASE MODULE BM XL SI Switch unit Cards Card IDs in Physical Card Slot No or Unit ID in Involved Diagnosis Frame in BM CRP Reports Cabinet mop BUE m Lows ome _ BPUG BPUG BMS 0 MSC or HMS TSU 6 MSD 8 AFB 7 BMS 1 MSC or HMS 0 TSU 6 18 MSD 19 AFB 20 TSC 0 TSC TSU 6 12 TSS 13 TSM 11 TSI 10 8 TSC 1 TSC 0 TSU 6 TSS 1 14 TSM 2 16 172 C DOT DSS MAX LIST OF CARD IDS IN SWITCH ALARMS amp POWER ALARMS FOR MAX XL Switch unit Cards Card IDs in Physical Card Slot or Unit ID in Involved Diagnosis Frame in BM Reports Cabinet o 79 m owe we o we ME me wm ANN b me me TIC 0 ISP SPC 1 TUI TIC 0 1 0 1 0 1 0 1 0 ISP SPC TUL TIC ISP SPC TUI TIC ISP SPC TUI TIC ISP SPC TUI 11 12 13 15 16 14 11 12 13 15 16 14 11 12 13 15 24 09 1 ISP SPC 1 16 MAINTENANCE PROCEDURES 173 Appendix 3 Switch unit Cards Card IDs in Physical Card Slot or Unit ID in Involved Diagnosis Frame in BM Reports o HM 11 ISP SPC 12 TUI TIC ISP SPC TUI 14 SMC card Not in BM of ADP cabinet DTU 2 11 12 DTU 2 16 15 Applicable in case of Single Base Module SBM XL configuration only Applicable if Digital Trunk Unit is equipped in the 2nd frame Note A
176. rchange the TICs and force the lines into service If they come inservice then make calls on these lines and check that everything is OK vi If service gets restored then wait for low traffic hour and then only start on the repair action But on the other hand if the service does not get restored via the other copy of TIC also proceed with the repair action immediately vii Put the standby TIC OOS and replace the SP card Bring the TIC inservice And make it the active copy Do this only in low traffic hour when there is very little traffic on this TU If the terminals remain inservice then make calls on few terminals and confirm that everything is OK Log the problem as H W fault in SP viii If on other hand the terminals start going OOS then interchange the TICs and again force the terminals which have gone OOS into service Put the standby TIC OOS again and replace the TIC card also Bring the TIC inservice And make it the active copy If the terminals remain inservice then make calls on few terminals and confirm that everything is OK Log the problem as H W fault in TIC MAINTENANCE PROCEDURES 119 Chapter 7 d 1 8 7 1 1 3 120 ix Xl If on other hand the terminals start going OOS then interchange the TICs and again force the terminals which have gone OOS into service Put the standby TIC OOS again and restore the old TIC amp SP card back Bring it into service Make it the active copy Jack out all the lin
177. re units faulty Fault isolation involves interpretation of Alarm and associated Report and if applicable use of on demand tests and reference to system trouble fixing procedures Repair action such as card replacement if not critical can be deferred to convenient hours as the system in most of the cases can automatically recover from faults through reconfiguration Periodic Routining This involves exercising those parts of the system hardware elements which are not normally in use so as to bring out the latent faults much before they adversely affect user services and to reduce the chances of an active unit going faulty in case of duplex units This can be done manually by issuing diagnostic commands by the operators System has however the capability to periodically routine entire hardware and generate routining reports Maintenance personnel have to dictate the time of day at which routining should be done the sequence in which units be tested and the periodicity of routining The strategy regarding assignment of active or passive role to a duplex unit found fault free after routining is to be chosen and communicated to the system in advance Following steps are needed for periodic testing a Deciding a schedule for routine testing b Conveying the schedule to the system Analysing routining reports Each one of the above steps is described below Deciding Schedule This involves the following i To choose
178. rn1 MAINTENANCE PROCEDURES 59 Chapter 4 4 4 3 60 Procedures Before any reconfiguration is done for printers one need to follow some procedure LP subsystem needs to be shutdown before reconfiguration and should be restarted after reconfiguration These procedures are listed below Shutdown for LP subsystem a login into 1 or root account b usr lib lpctl1 Restart for LP subsystem a login into 1 account b usr cdot lpctlO All the print requests in queue will be cancelled by shutdown and restart of LP subsystem as given above To start the printer subsystem by removing all input requests in the queue Login to lp account or root account gt usr lib lpctl1 gt usr lib lpctlO Check that all logical printers are accepting requests and physical printer prnl is enabled if not make the printers accept requests by giving the command gt usr lib accept prx where prx is the printer which was not accepting the print requests Enable the printer prn1 by gt enable 1 Handling of Cartridge Tapes Whenever you are using a cartridge for the first time the first thing to be done is to write a null on the cartridge It is done as follows a Check that the cartridge is not write protected b iop 5x gt c Now the cartridge may be brought into regular use C DOT DSS MAX SYSTEM INITIALISATION amp MAINTENANCE PROCEDURE For dumping u on a cartridge
179. runk group Contact the distant end and check whether they have put the trunks out of service Note in case of CDOT exchanges when a bothway trunk is made out of service by operator a permanent loop is extended on the trunk which can lead to distant end trunk going to LLO If the trunks in distant end are all right suspect the cable Perform TST TGP with test set 201 and verify that exchange side tests pass DTK Repeatedly Goes OOS SO and INS i Run TST TRML CARD Test set 403 for DTK CAS and Test set 401 for DTK CCS and try to locate the fault ii If this does not succeed inform the distant end iii Even then problem is not solved switch OFF and ON both PSUs of DTU and bring Digital Trunks inservice after TUCs come in service 7 2 PROCEDURE FOR HANDLING SUBSCRIBER COMPLAINTS 7 2 1 Telephone Dead Case I Problem concerns a particular subscriber i Perform both exchange side tests and outside plant open loop test on the terminal MAINTENANCE PROCEDURES 127 Chapter 7 7 2 2 7 2 3 7 2 4 128 ii iii If the outside plant open loop tests fail the fault lies in the outside plant Most likely there will be disconnection in the telephone line Capacitance test will fail with 00 uf as measured value in this case If the exchange side tests fail then the concerned line card is to be replaced Case II Quite a few number of telephones reported dead 1 li In this case confirm from the extern
180. s 1 Dial Characteristic Test 2 Loop Current Test 3 Loop Resistance Test Time Estimate Can t be estimated B List of test sets for Analog trunks TST TRM 1 Test Set No 201 Exchange Side Tests on Trunks Signalling 1 Line circuit current limiting circuitry check test 1 2 Line circuit current limiting circuitry check test 2 3 Seizure Test 4 Digit Outpulsing or Reception Test 5 Answer Test MAINTENANCE PROCEDURES 159 Appendix 6 Metering Pulse Test 7 Trunk Offer Test 8 9 Clear Back Test Clear Forward Test Time Estimate 10 secs 9 Test Set 202 Exchange Side Tests on Trunks Signalling Codec B N Be e Line circuit current limiting circuitry check test 1 Line circuit current limiting circuitry check test 2 Seizure Test Digit Outpulsing or Reception Test Answer Test Metering Pulse Test Trunk Offer Test Clear Forward Test Clear Back Test 10 Codec Analog to Digital Test 11 Codec Digital to Analog Test Time Estimate 15 secs 3 Test Set No 203 Answering Circuit Tests on Outgoing Trunks 1 2 8 Connection to Answering Circuit Tone Detection Noise Check 4 wire trunks 4 Test Set No 204 Codec Tests on Trunks 1 2 160 to D Conversion D to A Conversion C DOT DSS MAX TEST SETS C List of test sets for service circuits TST SRV 1 Test Set No 301 Loop Back Test on Receivers 1 Loop
181. s diagnostic report throws more light on the reason for the alarm It indicates the type of fault encountered and the identity of the card or cards which are most likely to be faulty b Alarm sequence number helps in correlating the report with the alarm on OOD terminal c An index on switch units required for diagnosis of a particular unit MAINTENANCE PROCEDURES is given in Appendix E 79 Chapter 6 80 iv v vl User Complaints User complaints such as no dial tone on off hook etc point towards some fault either in the system or in external plant Specific Observations Abnormality in system s behaviour can sometimes be inferred from routine observations Following examples illustrate this aspect a One fine day it is observed that system declare almost all the lines of the exchange faulty Hint This could be due to TTC being faulty b Quality of voice from subscribers belonging to a particular TU deteriorates on alternate days Hint This could be due to a new TIC card which has been recently introduced into the system Reports Scanning of various reports output by the system might reveal some abnormalities in system Typical findings could be as follows a Periodic routining of few switch units could not be completed b Too many audit failures within a given period Too many terminals faulty in single BM d A particular process recovers too often e Overload conditio
182. screen for 20 seconds and then scrolling takes over An alarm can be removed from the cyclic display on OOD through use of RTR ARM command without affecting the corresponding indication on ADP System also continues to remember the alarm till such time real cause is removed In order to read a particular alarm report from the cyclic display one has to wait till such time the report appears on the C DOT DSS MAX g MAINTENANCE OF SWITCH UNITS screen The desired information then can be quickly noted down Information consists of the following aspects Type of alarm Switch alarm Threshold alarm Overload alarm Battery alarm Power alarm Likely cause for the alarm not shown on OOD due to switch unit faults due to threshold crossover of terminal or service circuit faults due to overload condition due to battery low due to PSU faults Severity of alarm which indicates urgency of corrective action Critical urgent or non urgent alarms Identity of module responsible for alarm BM IOM CM AM Identity of the faulty unit within the module Unit identity for switch alarms Circuit type for threshold crossover alarm Trunk Service Circuit Line PSU identity for power alarm Trunk Group No in case of threshold crossover alarm due to many trunks being faulty ii Diagnostics Failure Report for Faulty Switch Units a In case of switch fault
183. se BMs to finish the initialization However during Part Init i e data down loading and other lower levels of initialization a maximum of four BMs can initialise simultaneously SUM initialization will take place only after initialization of the BM also defined as Home BM Conditions of Initialisation The system can go for initialization in two ways System by itself as a result of in built recovery mechanism 2 operator command as decided by Exchange Administrator System Initiated Levels of Initialisations System on its own may decide to go for various levels of initialization to overcome to the fault conditions This is a result of integrated inbuilt recovery process to overcome the fault conditions without manual intervention Level of Reasons Initialisation Code load e System power off on or reset Unrecoverable error in code area in simplex memory condition Data comparison error in code area Patch Init e Switch over during data loading Part Init Data comparison error in Read Only Data area Unrecoverable error in ROD area in simplex memory condition Stable Clear Data comparison error in Read Write Data RWD MAINTENANCE PROCEDURES 49 Chapter 4 4 2 2 2 Level of Reasons Initialisation area Unrecoverable error in RWD area in simplex memory condition e Overflow of software recovery counters within certain time e Failure of both time switches message
184. signalling information of 128 channels it communicates with Signalling Processor SP to receive send the signalling event on analog terminations It also uses one of the 64 kbps channel out of 128 channels towards Time Switch to communicate with Base Processor Unit BPU In concentration mode three other Terminal Units share this 128 channel link towards the Time Switch to have 4 1 concentration Terminal Interface Controller is built around 8 bit microprocessor with associated memory and interface and it is duplicated for redundancy Special Service Cards A Terminal Unit has some special service cards such as Conference CNF Card to provide six party conference Speech samples from five parties are added by inbuilt logic and sent to the sixth party to achieve conferencing Terminal Test Controller TTC Card is used to test analog terminal interfaces via the test access relays on the terminal cards Announcement Controller ANN Card provides 15 announcements on broadcast basis Only one service card of each type is equipped in a Base Module with provision of fixed slot for TTC and variable slots for CNF ANNC Announcement and Conference Cards are equipped in Terminal Unit through S W MMC command Two slots are occupied by each card i e 16 channels for each card are used out of 128 channels available on a Bus between a TU amp TS Digital Terminal Unit DTU Digital Terminal Unit DTU is used exclusively to interface digital tru
185. t manually v If the nature of the fault is serious enough then allot a new spare TEN to the subscriber if available use MOD SUB TEN Note if more then one TEN is faulty in the line card then replace the line card itself with a good spare vi Test the new line line card for all its exchange side functions and if it passes bring the line into service C DOT DSS MAX MAINTENANCE OF LINES TRUNKS amp SERVICE CIRCUITS 7 1 2 8 2 ROUTINING FAILED REPORT FOR LINES OUTSIDE PLANT TESTS i This report is displayed when outside plant tests Test set 102 for Analog Line amp 608 for digital line ii Check whether this report has come for only this line or it has come for a large number of lines in the BM iii If the report has come for only this line then do the following Issue the command TST TRM for that line with detailed report option and check the measured values iv If the measured values are definitely bad then inform the outdoor plant personnel v If the measured values are marginal then call the subscriber and enquire about the quality of the service Only if the subscriber has some complaint inform the outdoor personnel vi If large number of lines have gone faulty then perform the same test on some of the lines to confirm the fault If the fault persists then verify the sanity of TTC by testing it against a good switch room no vii If the TTC declares the switch room number also as faulty then it must be
186. t in as INS SBY the system needs to ensure that the data in the hard disk of this IOP is updated to reflect the latest status of the system This data is already available in the disk of the INS ACT IOP and the HDLC RS 422 link between the two IOPs is used to transfer the data needed to bring about this objective This procedure will henceforth be referred to as IOP Synchronization In the procedure described below it is assumed that IOP 0 is OOS SYS and IOP 1 is INS ACT If the situation is the reverse interchange IOP 0 and IOP 1 in the following description C DOT DSS MAX SYSTEM INITIALISATION amp MAINTENANCE PROCEDURE Step 1 If the Out of Service IOP is not in the WARM START level login to the admn account password is CDOTadmn invoke to bring it to this level Step 2 Perform the disk cleanup procedure to get rid of old data records that have already been backed up on to the cartridge This should be done on both the IOPs Clean up the data dump DUMPP directory using the following commands DEL FGP FILE for bc and tf file groups for old data Step 3 Now the OOS IOP is to be made OOS OPR in the system status map For this issue the following command from the INS ACT IOP PUT SWU OOS IOM IOP 0 Step 4 Issue the following command from the INS ACT IOP PUT SWU INS IOM IOP 0 The console terminal will display the following activities one by one to indicate that synchronisation
187. te sheet if required Please mail your comments to Your Reference Centre for Development of Telematics Name Attn Mr Y K Pandey Pi laa Director Systems pompae Address 39 Main Pusa Road New Delhi 110 005 Tel 91 11 5740374 Fax 91 11 5756378
188. that all HDLC cables from IOP X to the AP BP for SBM are in proper order iii From the CRP prompt on IOP X issue the command INIT IOP INS LEVEL FORCED This will bring IOP X in service Now if IOP Y is also in order iv Follow procedure 4 4 1 to bring IOP Y INS SBY Case II IOP X is not recoverable but IOP Y is functional and can be brought in service This condition is more serious than the previous one Some amount of data will probably be lost Follow the steps outlined below Copy out Exchange Data Billing Data Traffic Data from IOP X and COPY IN into IOP Y if it is possible to copy data from the unrecoverable IOP X If it is not possible to copy data from IOP X then do the following 1 Bring up to WARM START Level If IOP Y had gone OOS before the last data backups were taken perform the following step Step 2 Otherwise skip this step 2 Restore the latest Exchange Data Billing Data and Traffic Data backup on to IOP Y 3 From the CRP prompt on IOP Y issue the command lt INIT IOP INS LEVEL FORCED This will bring IOP Y in service 4 Wait for next billing dump to come on this IOP from memory BP Maximum wait time is twice the billing dump periodicity 5 Initialise the system with part init option using INIT SYS command 6 Rectify the IOP X and bring this as INS SBY using the procedure given in 4 4 1 Printer Procedure The Line Printer LP subsystem in IOP provides th
189. the list on IOP and ADP 41 AUD SS HANG This audits the space slots on the CM to BM Bus Space slots hanging even after completion of calls are released by this audit at SSC after checking for the existence of Call Manager CMR in the originating terminating BM 42 AUD CHNL HANG This audits the channels on DTKs connecting remote BM to the host exchange Channels which may not get released even after completion of the call are released by checking for the existence of the process which got the channel allocated 170 C DOT DSS MAX AUDIT SETS 43 AUD TERM BLK This audit audits the blocking ratio for the terminating calls for a BM against the actual overload level of the BM 44 AUD ALM The objective of having Alarm Audits is to that the alarms in the system are consistent with the actual System Status The following are the audits available as Alarm Audits Alarm Status Map in AP vs Alarm Status Map in IOP Unit Status in AP vs Alarms in AP Audits for counts in AP vs Alarms in AP Audits for Overload in Modules Vs Alarms in AP Audits for Power Supply Status in various Modules vs Alarms in AP Module Status in AP vs Alarms in AP Battery Status in AP vs Alarms in AP Alarms in ADP vs Alarms in AP MAINTENANCE PROCEDURES 171 Appendix C List of Card IDs in Switch Alarms amp Power Alarms for MAX XL a LIST OF CARD IDS AND THEIR ASSOCIATED CARD SLOTS Number in brackets under physical frame indicate frame numbe
190. the time of testing routining in such a way that subscriber services are least affected ii To choose appropriate interval for routining giving due weightage to the fact that faults should not remain hidden for too long C DOT DSS MAX 5 2 3 2 5 2 3 3 ROUTINE MAINTENANCE iii To choose a sequence in which units are to be tested iv To ensure that various units and links of the system do not remain in non active service for too long A typical schedule could be as follows Periodic testing is performed daily at low traffic hours say at 00 30 hrs at night Higher level unit say BP is tested before a lower level circuit say a terminal circuit gets tested After a duplex unit is found fault free it is assigned ACTIVE state and its mate standby state Care is also taken that links which have been unused earlier become under use active now Conveying the Schedule to System This involves preparing a file of commands needed for periodic testing and specifying in the system s calendar the time of day and the periodicity for executing the command file Once this is done at specified time interval System automatically keeps routining exchange hardware and generates reports In case of manual testing the operator needs to initiate the tests manually as per the schedule drawn Scanning Routining Reports Routining reports convey the test results to maintenance personnel It is essential to scan the said reports d
191. tre and await instructions If many of audit failures occur simultaneously check the quality of the service like DT delay etc If the service quality is bad then reboot the system INIT SYS STABLE CLEAR C DOT DSS MAX MAINTENANCE OF SWITCH UNITS Note Audit No 12 will fail in SBM as well as MBM even though it corrects the inconsistency Refer Appendix B for various audit sets 6 5 2 2 Loading Complete Report This report gives the information that the system has booted at such and such time The action is same as that described in the section for handling MLF alarm on ADP This report will also contain the level of initialisation and the reason for the initialisation 6 6 TRANSIENT FAULT HANDLING 6 6 1 Repeated Raising and Clearing of Switch Unit Alarms Repeatedly some unit is becoming OOS SUS and then coming back into service However there will be no alarm raised for the peripheral processor units like TIC TSC etc and other units like ADC CMS etc except BP AP SSC complexes including memory Only if the operator is vigilant this type of fault can be detected Another indication may be large number of unsuccessful calls as seen by traffic reports or overload getting declared although the BHCA is low Actions i Confirm that the unit is repeatedly going out of service by repeatedly issuing display command to check its status ii Make the unit OOS OPR ii Diagnose the unit repeatedly for 3 times If it
192. uation where both the IOPs are Out of Service and presumably Out of Order In this condition the system functions at a reduced efficiency with some of the features not operational as password change for Dynamic Locking no traffic and billing dumps etc However as the system software cannot resort to various levels of system initialisation in case of irrecoverable errors there is a major risk of indefinite exchange or group downtime It is therefore essential that whenever such a condition arises the maintenance personnel who will be notified by a Critical IOP Alarm Indication on the Alarm Display Panel ADP take immediate action to rectify the situation and attempt to bring atleast one IOP in service To describe a situation when both IOPs have gone OOS the following terminology will be used IOP X is the IOP that was the last IOP to be in service IOP Y is the IOP that had gone out of service before IOP X In this respect the operator may face one of the two situations IOP X is in order and can be brought in service IOP X is not recoverable but IOP Y is functional and can be brought in service Case I IOP X is in order and can be brought in service Follow the steps described below C DOT DSS MAX 4 4 2 SYSTEM INITIALISATION amp MAINTENANCE PROCEDURE i Bring IOP X to WARM START level if it was not already so The procedure for doing so has already been discussed in previous sections Check
193. ucting any exchange side tests on trunks and at that time there was no free trunk of the required type available in the system TST TRM for an ICT requires a free OGT and vice versa As such this condition can occur only in a very remote circumstances If it happens frequently report to support centre ANSCKT NOTSZD This message is displayed when then there is no answering circuit receiver available for conducting the answering circuit test for OGTs Procedure for Handling Problems Detected by Traffic Reports Traffic can be a good means for detecting problems in the system that could not be caught by other fault detection mechanisms Too many Call Failures in all Trunk Groups with MF Signalling i This can be due to some MF sender receivers going faulty The system either has not yet detected the problem or the system has detected the fault but number of circuits that have gone faulty is not large enough to raise an alarm Under such conditions operator is required to check the status of all MF circuits conduct loopback test TST SRV TST SET 301 on all the MFCs and replace the faulty MFC if any Too Many Call Failures in One TGP i Under such conditions the operator is required to test all the trunks in that trunk group For outgoing trunk group the answering circuit should be performed ii If the failures are in the Incoming side then perform the exchange side test on that trunk group TST TGP TST SET 202 iii If the
194. via 2 Mbps digital links The number of 2 Mbps links between the Main Exchange and RSU is primarily determined by the traffic A maximum 16 PCMs can be provided between a RSU amp Main exchange Analog and Digital trunk interfaces are also implemented in RSU to support direct parenting of small exchanges from RSU itself instead of parenting it to the main exchange which will ultimately save the media required from main exchange As far as call processing is concerned RSU is an autonomous exchange capable of local call completion Operation and maintenance functions are handled by the host exchange In the event of failure of PCM links RSU goes into standalone mode of operation In case it is not possible to process a call request due to unavailability of links to the host the subscriber is connected to appropriate tone or announcement During standalone mode of operation the local and Incoming terminating calls in RSU are switched and the metering information of all the RSU subscribers is stored in the RSU It is sent to the host whenever the PCM links are available again Only the even numbered BMs can be configured as RSU i e a maximum 16 RSUs are possible in C DOT DSS MAX XL and 8 RSUs in MAX L MAINTENANCE PROCEDURES 11 Chapter 2 2 6 2 4 2 8 12 COMMON CHANNEL SIGNALLING NO 7 AND ISDN Common Channel Signalling is pre requisite to provide any value added service in the network e g Intelligent Network Services ISDN serv
195. y card to TIC and restore SP card CASE TIC INFORMATION MEMORY FAILURE Explanation TIC Card is faulty switching logic ckt is bad TSC TIC links is bad TSC itself is bad Actions Replace the TIC if only one TIC is shown faulty Replace TSM TS I or PSU II if all TICs are failing in same test Check cable between TSC TICs C DOT DSS MAX MAINTENANCE OF SWITCH UNITS In this test the TSC inserts a pattern in all the 128 channels towards that TIC and loops back at the TIC end and extract the pattern at TSC and compares If this test fails on all the TICs then TSC could be suspected and a diagnosis of TSC is required to be done If the diagnosis passes then TSM or TSI or PSU could be indirectly contributing to the noise at the output of the TSI or all the PCM links 6 4 1 1 4 IN CASE OF TICS BEING CONCENTRATED Refer Fig 6 3 a CASE FAULT PROB FOR MORE THAN ONE TIC IN THE SAME PLANE IN A CHAIN i Following points are to be considered during concentration TIC trouble shooting When all the members of TIC concentration chains are O K then the chain can remain 1 5 or INS SBY mode Criss cross configuration is not possible If all the members of the chain are not O K then the units which are O K will be INS ACT or INS SBY mode Also the plane with more no of good units in the chain will be INS ACT and the other will be INS SBY Whenever any unit in a chain is OOS OPR the other units of

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