Home

Single point of Control for a Distributed System

1. Single point of Control for a Distributed System Centralized Control of a Real Time Ethernet Measurement System Master of Science Thesis in Networks and Distributed Systems FERNANDO FERRI VIDAL Chalmers University of Technology Department of Computer Science and Engineering Goteborg Sweden October 2011 The Author grants to Chalmers University of Technology and University of Gothenburg the non exclusive right to publish the Work electronically and in a non commercial purpose make it accessible on the Internet The Author warrants that he she is the author to the Work and warrants that the Work does not contain text pictures or other material that violates copyright law The Author shall when transferring the rights of the Work to a third party for example a publisher or a company acknowledge the third party about this agreement If the Author has signed a copyright agreement with a third party regarding the Work the Author warrants hereby that he she has obtained any necessary permission from this third party to let Chalmers University of Technology and University of Gothenburg store the Work electronically and make it accessible on the Internet Single Point of Control for a Dis
2. After waiting for the previous tasks have finished it 1s executed an expect script named transferResults sh which creates an sftp connection with the Windows machine and it will transfer to the coordinator machine the timing analysis and the statistics of the current capture After this procedure the desired job is done the capture has been started from a coordinator machine and it has obtaining the results of that capture without being needed any manual interaction with another machine CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 38 Centralized Control for a real time Ethernet Measurement System 3 4 2 Design separate Control and Measurement networks As it is described in section 2 there is only one network domain for both measurement and control traffic so the coordinator makes connection to different computers in the same network as the measurement card wants to capture specific traffics which is generated by H1 and H3 In this way those control packets related to control network might interfere the desired traffic in the switch and change the measurement results for queuing and forwarding time Therefore it is decided to have separate networks for each purpose One network is dedicated for measurement purpose The second network is designed to control the different parts of the system called control network The third the office network is used by the persons at the office for connecting to I
3. M Sc Networks and Distributed Systems 56 Centralized Control for a real time Ethernet Measurement System Click scripts and measurement procedure The following section describes how the initial measurements in setup have been performed and some experiences The Click script that is used to generate traffic during the tests have been called FastUDPSource click on both hl h2 and h3 In these we set the rate parameter high in h3 so it works as stress flow The script sink click on h2 acts as a sink for both the flow from h1 and h3 and the number of packets received from each flow can be read by running cat cat proc click count_from_hI count cat proc click count_from_h3 count Log in with SSH to the sources hl and h3 FastUDPSource click can be started on them without the SSH connection hangs Download filter in NetAnalyzer by selecting File Filter Settings and select Load Select the file C Documents and Settings All Users Documents net_ analyzer filter reyect_h3 nff This filter rejects all packets coming from host h3 by matching against the Source MAC Address Sink h2 h2 should be operated via the directly connected keyboard and monitor because SSH connection hangs when running click script on this computer e Login as root e Start the click by issuing the command click install root click sink click e Go to the folder click e We can now check how many packages the sink accepted by giving the command cat count fro
4. Real Time scheduling TCN Analyzer Network design Centralized Control for a real time Ethernet Measurement System Acknowledgements This has been a very intensive project and I would like to thank all the people that directly or indirectly participated in it It has been carried out under supervision of Jan Jonsson and Jonas Lext whose guidance and encouragement have been crucial to finish this project successfully To start I want to give my best gratitude to Fatemeh Ayat my friend and co worker in this project without who this would not have been possible and who contribute to make this project an enjoyable experience As well I want to thank Mohammad Ibrahim for his help and advices at the time of programming the boards This has been the first time I worked in a project for a company and I would like to thank Lars Brohne Jonas Lext and Thomas Lundqvist for their support and for giving me the chance to take part in it They were very helpful and understanding which made working with this project a lot more enjoyable Finally and not less important I want to thank my friends and family strongly for the support and affection given to me during my thesis period and these two years of my Master studies I have spent abroad CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 4 Centralized Control for a real time Ethernet Measurement System Table of Contents ABSTRACT 3 A
5. Flow description Host hI sends packets that are captured by the NetAnalyzer card adding a time stamp and sending them later to the switch The forwarding time at the switch is calculated when the packets are sent back to the NetAnalyzer card using the previous time stamp Next the packets are stored in a hard disk where different format conversions have to be done before the data is sent to the Stream Analyzer for calculating the forwarding time Furthermore all packets are sent to the host 42 where they are classified and counted depending of which host they come from At the same time it is possible to generate another data flow in the host h3 This will introduce another data flow competing for forwarding time in the switch making the packets being stored into a queue before being forwarded Figure 3 shows the packet flow in the system CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 16 Centralized Control for a real time Ethernet Measurement System tellur NetAnalyzer gt 192 168 0 10 RedFox 192 168 0 253 00 00 00 00 00 01 ethl 192 168 0 2 00 11 11 0E 7E 80 Switch 192 168 0 3 S OUFE dod sand es dg Flow hl Flow h3 Figure 3 Traffic flow In Figure 3 is shown how are connected the hosts in order to measure the packet flow providing from A1 In this case h3 has been introduced for generating traffic that could interfere in the switch and increase the switch forwardin
6. In this process we had to deal with some problems due to some functions do not behave in the same way in Linux and Windows such as the function that provides the path and the function used to read from a file Another issue is the way the path is defined in the program to find the desired files and also the way they tokenize the names So the program should be placed in a directory whose path does not contain spaces Indeed there should be no space in phrases used in python programs python is used for generating plots in StreamAnalyzer Using the correct version of python and its libraries to plot the graphs was an issue which is solved by installing python 2 6 pylab and other related programs On the other hand to deal with the problems to set the system we had to set the environment path according to the different programs which deal with using StreamAnalyzer such as C compiler for windows python and pylab This task seems a simple one at the first glance but testing and debugging the program to find out the problems is not straightforward After all we succeed creating the Windows adapted version which provides same results and plots as the Linux version CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 30 Centralized Control for a real time Ethernet Measurement System 3 2 Create Hilscher control software The way to interact with the card manually to start and stop capturing is done through
7. a flow source Route to the lab network TCN s office computers are attached to the Chalmers office network which is shared with all the other incubator companies on sixth floor The office network address is 172 16 3 0 255 255 255 0 TCN s lab network on the other hand contains two networks measurement network and control network Measurement network has the address 192 168 0 0 255 255 255 0 and Control network has the IP address 192 0 3 0 255 255 255 0 The three networks are connected via one of the Click machines r0 which acts as a router To tell the computer how to access the lab network use either the route command or a system tool Route Command route add net 192 168 0 0 netmask 255 255 255 0 gw 172 16 3 225 route add net 192 0 3 0 netmask 255 255 255 0 gw 172 16 3 225 Now this step is done in script routingTable sh so it is not needed to do this step manually Set the Internal Clock The internal clocks of hosts hl and h3 will probably be wrong at boot time This leads to a compiler warning when compiling the Click module and possible that not all files are recompiled The right time can be set with the command date date set 2010 04 20 15 32 00 File Exchange If one needs to transfer for example a new click script or Click elements from argon the scp command could be used scp r tenflowsrc username 192 168 0 1 home username click 1 5 0 elements linuxmodule CHALMERS Computer Science and Engineering
8. to be able to discard the packets which are not UDP After all the source and destination IP addresses are obtained from the IP header The UDP packet starts after the IP header including options So the remaining fields including UDP source and destination ports are obtained in this part This process continues for all packets till the total data size obtained from file header is reached Limitations solved till now After adapting StreamAnalyzer or being executed in Windows 3 1 creating the software that starts stops the capture without needing interaction of the user through its GUI 3 2 and finally in this section 3 3 after reading directly from the hea file which is the format in which NetAnalyzer card s driver stores the capture several manual steps can be omitted It includes all conversions steps and the steps in which the user needed to move the file after the conversion to another machine in order to be processed by StreamAnalyzer At this point the capture is created without needing interact with any GUI being stored in the local Windows machine that contains NetAnalyzer Card and being possible to run StreamAnalyzer directly from this machine and reading the original hea file in order to obtain the desired results This implies an important improvement in order to achieve the total automation of the system and as well a reduction of the time needed for performing a capture and its corresponding analysis CHALMERS
9. 0 3 13 hetAnalyzer Measurement Card installed on Tellur machine 192 0 3 12 VY H2 ethi j 192 168 0 2 aer eth eth 192 0 3 11 Figure 20 Network Topology view 1 CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 59 Centralized Control for a real time Ethernet Measurement System 172 16 3 0 OFFICE NETWORK 2 BF Tellur Windows Mercury Linux 172 16 3 103 COORDINATOR NetGear Switch ethi 172 16 3 225 eth3 lt gt 192 0 3 1 P etha 192 168 0 254 ROUTER 192 0 3 0 CONTROL NETWORK eth2 c e 192 0 3 1 etn az 192 0 3 11 ethi af 192 168 0 3 id ethno eth2 192 168 0 1 F 192 0 3 12 M eth 192 168 0 0 MEASUREMENT NETWORK 192 168 0 20 192 168 0 30 netAnalyzer Measurement installed on Tellur machine Figure 21 network topology view 2 CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 60 Centralized Control for a real time Ethernet Measurement System 172 16 3 0 OFFICE NETWORK a Mercury Linux COORDINATOR Tellur Windows 172 16 3 103 NetGear Switch pe 192 0 3 0 CONTROL NETWORK ethi 172 16 3 225 eth2 eth3 192 168 0 254 192 0 3 1 NetGear Switch 192 0 3 2 ROUTER 192 168 0 0 MEASUREMENT NETWORK E F a a E a4 m __ Westermo Indu
10. CAN20A pdf 18 Jeff Nowling Industrial Automation Engineering consultant How fast is Ethernet http www cross automation com TechCenter A ppNotes Supplier Ethernet pdf 19 Meng Liu Response Time Analysis of Ethernet Flows with Fixed Priority Evaluation and Improvement of TCN Analyzer Scheduling Analysis Theory M Sc Chalmers University 20 IAR framework http www 1iar com en Products AR Embedded Workbench 21 IAR Systems http www iar com en 22 Symtavision http www symtavision com 23 Inchron http www inchron com 24 Real Time at Work http www realtimeatwork com 25 Wikipedia http www wikipedia org CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 55 Centralized Control for a real time Ethernet Measurement System 9 Appendix Appendix A Measurement Setup before the thesis project This section contains specific setup information that was only valid for the initial network architecture previous to the start up of this project After the development of this project this information is not needed anymore being all the tasks automated and the network architecture updated Boot lab network Start the machines r0 h1 h2 h3 the voltage source which drives the Redfox switches and the netGear switch for control network Click The hosts in the lab network uses the open source project Click which enables them to function as e g
11. Cap_O_flowParam Cap_O_fwd_tm_ti Cap_O_ fwd_tm_ti tx 2 467700 s is 0 2 775834 s is 0 012500 s maxit_ 500000_s maxft TapA maxim avera minim Cap_O statistics Cap_O_ tapb_link_ tx utilization_ti_2 467700 s is 0 012500_s maxit_ 131 607056_us png 5 d110926_134256 5 items Free space 129 1 GB te B gue SSS Figure 17 Results of the measurement The results consist in different files that define the characteristics of the flows and several plots that are the result of performing the timing analysis of the generated traffic As well one text file containing the statistics timing results that are possible to be observed in the plots is created for simplifying the task of comparing the results of the execution CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 47 Centralized Control for a real time Ethernet Measurement System Figure contains the files created as a result of an execution which are stored into a folder with the time in which was performed the measurement It contains the file in which the user defined the flows characteristics so it is possible to compare the timing analysis provided for a certain flows setup with different flow number packet size priorities and period Furthermore three plots are created in which it is possible to observe which is the maximum forwarding time in the system in other words the maximum forwarding
12. Computer Science and Engineering M Sc Networks and Distributed Systems 33 Centralized Control for a real time Ethernet Measurement System 3 4 Create Coordinator software and network design Once we have created the tools for initiate a capture without needing human interaction in the previous sections avoiding to use GUIs format conversions and manual movement of files it is possible to design and implement a centralized control unit which will take care of all the actions needed for performing every step in this process in order to make a measurement It is also considered networks improvement and the adaptation of new devices which need to be added to the system Furthermore this process includes modifying and improving several of the steps that were executed as isolated before 3 4 1 Create Coordinator software This section is the main target of the project to implement a centralized program to coordinate the whole process This program called the Coordinator executed in a Linux machine at the office network will do all the tasks described below interacting with the different computers and transferring the results of the execution to the machine running the coordinator program Therefore there is not needed any other manual contact with other machines to obtain the result of the analysis The different tasks are e Connect to the switch to set the parameters according to the configuration file which should be same as TCN Analyzer
13. and CPAC a company of Volvo group have already verified the possibility of replacing partially or completely CAN bus with Ethernet without major changes Another company that shows interest into the field is Siemens Automation the largest company in the world in this segment has recently started a project intending to verify Ethernet usage in time critical applications 16 There is no doubt that the usage of Ethernet in time critical applications will be a reality not far away in time and TCN Analyzer product together with TCN Measurement tool developed during this project for testing and verifying TCN Analyzer s predictions will be well placed in the new market of this applications CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 52 Centralized Control for a real time Ethernet Measurement System 6 Conclusions This report claims to give an insight into the current protocols used for transmitting data into a communication link from the point of view of time critical applications It points out the growing industries interest in Ethernet protocol for time critical applications It provides better throughput and do not have certain limitations such as the previous ones described about CAN TCN Analyzer tool allows designing Ethernet networks and verifying the time correctness of time critical applications giving a prediction of the maximum forwarding time for a flow in the network During this pro
14. buffer mode it needs to be specified before starting the capture The function netana set filelist defined in the API 4 allows to define how many files have to be created This will limit the maximum data that it can be stored Also it 1s necessary to set up ring buffer mode in the function netana_start_capture which starts the capture In this case it has been decided not to enable the ring buffer mode which it will imply that StreamAnalyzer will needed to process more than one file and some extra time should be dedicated for this On the other hand the capture size is up to 1GB and it has been considered as enough data to be processed in order to perform the analysis CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 31 Centralized Control for a real time Ethernet Measurement System 3 3 Avoiding format conversion As mentioned the StreamAnalyzer program is not designed to read the hea file and it needs some conversion to be done In this step to reduce this inconvenient way of reading the captured data we try to read directly from the binary file hea in StreamAnalyzer program The hea file structure is described in the NetAnalyzer API 4 As it is shown in Figure 10 each file has a header part which is followed by captured packets Ox00000000 HEA File header Ox00000020 ullDataSize 0x20 End of file Figure 10 structure of the binary file with hea format The file header conta
15. configuration for the network including issues such as routing table configuration and system setups are included in the Appendix A Notice that this settings need to be done manually each time the system is started in order to performing measurements The aim is to avoid these manual procedures at the end of this project and provide a centralized measurement control system that performs all the tasks without needing the user interaction A Boot lab network Start the machines r0 which act as a router A7 and 43 which act as a traffic generators and A2 which acts as a receiver of the data flow It is important before starting the capture of packets make a Ping call to all different hosts in the system make a Ping from A and h3 to h2 and vice versa This is done for updating the switch table and avoid that packets are broadcasted if the switch does not have stored from which port number is reachable the desired host This is done in every machine what implies a considerable time waste B Start the packet capture using the Card Analyzer GUI The traffic delivered by A7 goes directly to host Tellur containing the Real Time network card which captures the packets add a time stamp before forwarding them to the switch This card only provides a graphical interface GUI where it has to be pressed the button START for initiating the capture of packets Before generating the packet flow in h1 and h3 is necessary to press the button START
16. configuring the filters This graphical interface is compatible with Windows XP Vista and 7 operating systems so we used Windows XP PC for the Measurement card interface The captured data is saved on the machine hard disk in hea format but the interface has the option to convert it to other formats like pcap to be readable with other programs like Wireshark CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 22 Centralized Control for a real time Ethernet Measurement System GUI used for the user in order to generate a capture Start button to stop capturing packets Stop button and converting the format Convert button r netANALYZER File Settings TAP TAP B Status STOP PED Port 0 Port 1 Port 2 Port 3 UP UP Mo up o J Inactive INacTive INACTIVE INACTIVE Transparent Mode Frames received OK Check sequence errors Alignment errors MII RX_ER errors Short frames Frames too long Start of frame delimiter errors Preamble too long Preamble too short Frames rejected by filter Minimum Inter Frame Gap ns BusLoad J bi i 0 Recording Time Status Capture Data ready GPIO Start Stop manual Figure 4 Hilscher s Measureme
17. every card is constantly receiving requests The coordinator executes a java program which sends an UDP message to each board with the propieties of the desired flow being possible different properties for each board Finally every board that has received the propieties of the desired flow will be waiting for the order of start generating the traffic flow Start sink In this step the coordinator connects with the Sink machines through SSH in the same way than before using the expect script sink sh This expect script execute the click script which will be listening for packets Furthermore it 1s defined a time which is supposed that have to last the capture and after expiring this time it will stop the click script which listen for packets and will turn down the SSH connection with h2 Start capturing packets in NetAnalyzer measurement card windows machine This step is done executing the expect script capture sh It connects through SSH with the Windows machine containing the NetAnalyzer card and executing the exec file generated in the section 3 2 which starts capturing packets in the measurement card It is defined a predefined time value which is supposed to last the capture Therefore after expiring this time the capture is stopped previously needed to press the button STOP Next it 1s executed StreamAnalyzer which analyse the previous capture and calculate the timing plots and statistics To finish it will move all the resul
18. script contains the setup for sending certain number of packets data rate and packet length This is done by the command click install FastUDPSource click This command will start the traffic generation from At the same it is possible to create another data flow from the host A3 in the same way login on from Mercury to h3 using SSH with the command root 192 167 0 3 with the corresponding password The aim of this data flow is to cause collisions between the traffic from h and h3 where some packets should be stored into the switch queue increasing the forwarding time Later on in the analysis will be possible to analyse in which moment collisions take place and what is the forwarding time for these packets E Stop the packet capture using the Card Analyzer GUI Once it has been decided that enough traffic have been captured in order to perform the analysis it needs to be pressed the STOP button at the NetAnalyzer GUI It will stop capturing packets and the capture will be available in a binary file with extension hea F Obtain number of packets received in sink Next at the end of the capture and after being pressed the stop button we will be able to obtain how many packets have been received in A2 executing the script that counts the received packets from A and h3 cat click count from_hl count click count_from_h3 count This command will print in the first line the number of received packets from h and in the second
19. the graphical interface which is not suitable for automated systems In this way we decided to implement control software to interact with the card through C API which is provided by Hilscher In this program we will run start and stop capturing without using the graphical interface So there will be no need of manual human interaction in this way In order to achieve this the following functions defined in the API 4 are used netana driver information This function gets the driver s information and its current state Furthermore it says if there is some error accessing to the driver After getting access to the driver and checking that there is not any error it is necessary to define the parameters for the capture The next functions are used e netana set filelist This function activate capturing data into a hea file It defines the file path file name number of files to be created and file size netana start capture This function defines parameters to start capturing such as capture mode capture reference time and etc Ring Buffer Mode The latest version of the measurement card driver supports ring buffer mode which allows to store captured data in more than one file Each file size is fixed to 1 GB so 1f the maximum amount of packets that fits into a file is reached it will continue storing packets in the next file until the capture is finished or there is no more file to continue storing In order to work in ring
20. virtual model of the network to analyse Next in order to verify the correctness of the prediction it 1s needed to run the TCN Measurement tool described in the previous part developed in this project The first improvement is to consider how both programs are executed not existing interaction between them Due that the user defines the flows propieties at the same time that creates the model of the network using the GUI of TCN Analyzer it should be possible to send this information to the measurement system without being needed the user to rewrite the flows propieties in a text file as it is described in section 4 Another improvement could be to plot in the same graph the prediction made by TCN Analyzer and the value calculated by TCN Measurement system of the worst forwarding time Regarding to the research this pretends to extend sectionl Introduction where it is described the main propieties of CAN and Ethernet as a protocols for transmitting data into a link Furthermore it is discussed why industry is interested in applying Ethernet technology when they currently use CAN bus commutation and how TCN Analyzer takes advantage of the lack of tools that perform timing analysis design and verification of Ethernet networks As it has been described most of applications in industry operate with CAN and the programs currently available for design and verify networks in these time critical systems operate using CAN networks Thus this tool p
21. 9 60 61 Centralized Control for a real time Ethernet Measurement System 0 Method This section pretends to describe the method in which the tasks and requirements were established for the development of this project Due that this is a project for a company which aims to solve a specific need a meeting with the managers of the company took place in order to find out the requirements and define which tasks to perform This is reflected in the ntroduction section It pretends to describe the company s product TCN Analyzer in the subsection TCN Analyzer tool and define the problem that this project has to face in the subsection Purpose of the thesis work First of all it was decided to do a pre study of the system described in section 2 The aim of this was to obtain a clear insight about the initial system in order to define properly the requirements of this project After the pre study phase all the manual steps of the manual measurement process were clearly defined This was really important in order to decide which tasks to do for performing the automation of the measurement system the aim of this thesis project Finally together with the managers of the company it was decided the road map of this project It is described in section 3 Design and Implementation and it 1s structured in two parts A Software Development develop a coordinator program which will interact with the different parts of the system and provide t
22. ATIONS 54 8 REFERENCES 55 9 APPENDIX 56 APPENDIX A MEASUREMENT SETUP BEFORE THE THESIS PROJECT 56 APPENDIX B NETWORK ARCHITECTURE 59 APPENDIX C COORDINATOR PROGRAM 62 CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 6 Centralized Control for a real time Ethernet Measurement System List of Figures Figure l Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure ll Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 Figure 18 Figure 19 Figure 20 Figure 21 Figure 22 CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems T CN Analyzer tool GUI Network topology Traffic flow Hilscher s Measurement Card Interface GUI Wireshark format conversion Click interface program code executed at the terminal Flow from hl forwarding time Serialization pattern at max forwarding time interval Jitter at max inter arrival time period structure of the binary file with hea format Measurement Network Control Network Office Network Complete Network topology Different networks interacting in the Measurement System TCN Measurement tool execution environment Measurement results Analysis performed by StreamAnalyzer TCN Analyzer GUI Network topology view I Network topology view 2 Network topology view 3 12 15 17 23 24 23 a7 28 29 32 39 40 41 41 45 46 47 48 59 5
23. CKNOWLEDGEMENTS 4 TABLE OF CONTENTS 5 LIST OF FIGURES 7 0 METHOD 8 1 INTRODUCTION 9 1 1 ETHERNET VS CAN IN TIME CRITICAL SYSTEMS 9 1 2 TCN ANALYZER TOOL 12 1 3 PURPOSE OF THESIS WORK 14 2 PRE STUDY PHASE 15 2 1 SYSTEM OVERVIEW 15 2 1 1 TRAFFIC FLOW GENERATION 16 2 1 2 MANUAL MEASUREMENT PROCEDURE 18 2 2 DIFFERENT INTERFACES 22 2 2 1 REAL TIME ETHERNET MEASUREMENT CARD INTERFACE 22 2 2 2 WIRESHARK INTERFACE SECOND FILE CONVERSION PROCESS 24 2 2 3 CLICK INTERFACE 25 2 3 SCENARIOS AND EXAMPLES OF MEASUREMENTS 26 2 3 1 SCENARIO 1 26 3 DESIGN amp IMPLEMENTATION 30 3 1 MAKE STREAMANALYZER WORK ON WINDOWS 30 3 2 CREATE HILSCHER CONTROL SOFTWARE 31 3 3 AVOIDING FORMAT CONVERSION 32 LIMITATIONS SOLVED TILL NOW 33 3 4 CREATE COORDINATOR SOFTWARE AND NETWORK DESIGN 34 3 4 1 CREATE COORDINATOR SOFTWARE 34 3 4 2 DESIGN SEPARATE CONTROL AND MEASUREMENT NETWORKS 39 ROUTING TABLE SETUP 42 3 5 EXTEND THE ARCHITECTURE BY ADDING CEC BOARDS 43 ADD BOARD TRAFFIC GENERATORS 43 BOARD SPECIFICATIONS AND PROGRAM 43 INTEGRATING BOARDS INTO THE COORDINATOR PROGRAM 44 FINAL TOPOLOGY OF THE SYSTEM 45 4 EXECUTION AND RESULTS 46 COMPARING THE MEASUREMENTS RESULTS WITH THE TCN ANALYZER PREDICTION 49 GOAL OF THE COMPARISON 50 CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 5 Centralized Control for a real time Ethernet Measurement System 5 FUTURE WORK 51 6 CONCLUSIONS 53 7 TERMINOLOGY AND ABBREVI
24. LM wenchao pcap Wiresha laity Edit View Go Capture Analyze Statistics Telephony Tools Help B Open aroja Ba eFt RRAN Open Recent gt Merge y Expression Clear Apply gt Close Ctrl W Destination Protocol Info E Save Ctri S Save As Shift Ctrl S File Set gt Export b as Plain Text file as PostScript file amp Print Ctrl P as CSV Comma Separated Values packet summary file A Quit Ctri Q as C Arrays packet bytes file Y lt 4 b Frame 1 426 bytes on wire 3408 bi b Ethernet II Src LiteonTe_3f 98 9 gt Internet Protocol Src 192 168 0 9 gt Transmission Control Protocol Src b as XML PSML packet summary file as XML PDML packet details file Selected Packet Bytes Objects saaaaae 0000 00 22 Sf 3f 98 91 00 22 Sf 3f 98 91 08 00 45 00 en one eee eed eet 4 0010 O1 9c 60 e6 40 00O 80 06 16 93 cO a8 OO Sb cO a8 ae ey ee es 0020 00 37 08 bf 00 50 f9 a3 a7 62 18 32 4f 2e 50 18 7 P b 20 P 0030 fc 00 a4 49 00 00 47 45 54 20 2f 20 48 54 54 50 I GE T HITP p Figure 5 Wireshark format conversion CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 24 Centralized Control for a real time Ethernet Measurement System 2 2 3 Click Interface The Click software is used to generate the packet flow In this way there is no graphical interface and we use the
25. PACKET SIZE bytes ethernet Proiority sink delay Active Y N 10 140 7507 1 OY 20 60 750 4 2 OY 30 140 2940 2 OY a gp g g DO Gt M B Ig T i UT 8 lows Cis ca aca Tee Figure 18 Resulting analysis performed by StremAnalyzer As it seen it has been avoided any extra manual interaction Just is needed to run the main program which will take care of executing and processing the local outputs that before needed to be take in consideration manually After this the results will show up at the same machine where we executed the program CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 48 Centralized Control for a real time Ethernet Measurement System Comparing the measurements results with the TCN Analyzer prediction As it has been described before TCN Analyzer is the main tool or product developed at the company Time Critical Networks AB This tool is an interactive program in which the user defines the components of system to be analysed and the flows desired in it It takes advantage from the scheduling algorithms developed at the company and improved by Meng Liu s thesis project 19 File View Analyze Help Host Editor Bridge Editor Link Editor Frame Template Edi
26. Unix terminal and Click install script as an interface to generate the desired flow For instance there is a function called FastUDPSource as shown in Figure 6 which can set the flow parameters like rate number of packets length address and port of source and destination etc By running the click install script on this function the flow will be generated on the network root hl click File Edit View Terminal Tabs GNU nano 1 3 12 File FastUDPSource cLlick ffastUDPSource 2027 RATE 100000 LIMIT 61 LENGTH Matkort anser frejmen f r stor vid 60 0C F1 CD 42 BE SRCETH 192 168 0 1 SRCIP 15000 SPORT 6 11 11 8E 7E 86 DSTETH 192 168 0 2 DSTIP 15000 DPORT true CHECKSUM 1 INTERVAL r gt ToDevice eth Read 13 lines me Get Help WO WriteOut W Read File gj Prev Page Wi Cut Text W8 Cur Pos ei Exit ee Justify WY Where Is y Next Page W UnCut Text y To Spell Figure 6 Click interface program code executed at the terminal On the other hand at receiver we use the other function as an interface to categorize and count the number of packets that are sent from different sources As an example we use the click install script to start the function sink click which categorize the packets from different sources and count the number of packets received from each source CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 25 Centralized Control for a real time Ethernet Measu
27. ansmit lower priority flows detect it Therefore higher priority flows are transmitted first and the others will wait CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 9 Centralized Control for a real time Ethernet Measurement System CAN is used in embedded systems and automotion systems 8 being possible find it in e Trucks control systems e Train systems e Marine systems e Industrial automotion e Elevators e Medical equipment CAN is a protocol used in time critical environments where integrity fault tolerance and latency constraints are required In case of not fulfil these requirements safety could be compromised and it could be a risk for human lives On the other hand CAN protocol has some limitations and propieties e Low bit rate where maximum velocity is 1 Mbit sec e Throughput depends on bus length achieving the maximum velocity up to 30 m e It has a non destructive arbitration when more than one node pretends to transmit The node with highest priority still will be able to transmit their message CAN limitations specially the low bit rate or velocity in which data can be transmitted and the relatively short length of the buses used for transmission brings up the necessity of replacing this protocol which is the one used nowadays mainly in the automotive industry for a better and more efficient protocol On the other hand Ethernet is a networking protocol for Local Area Networ
28. cap file but change the extension to csv Select file format csv Misc e To edit scripts use for example the application nano nano FastUDPSource click e A click install scripts can be stopped with the command click uninstall e Through the tests that found that the Click element FastUDPSources can send packets with the length parameter is lt 1518th In all cases took Basin in h2 receive as many Ethernet frame sent Should actually theoretical upper limit be 1514 bytes According to a note in the Click script will however the measurement card to protest when LENGTH gt 1515 which agrees with the theory Could be of interest to some time to examine where the four extra switches will be added Could it be that the extra bytes are inserted into the header to match the second Ethernet headers than the basic version Network Shutdown SSH root 192 168 0 1 shutdown h 0 SSH root 192 168 0 2 shutdown h 0 SSH root 172 16 3 225 shutdown h 0 CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 58 Centralized Control for a real time Ethernet Measurement System Appendix B Network Architecture Tellur Windows 2 163 103 a tW m m Ta N pi oa wW mi a i t pa a PR 5 e EOR ma kez g o i ant oS aa gt G oO ws i W oa o a i 7 a 7 5 192 168 0 254 ndustrial Switch emo 192 168 0 253 West eth 3 192 168 0 3 eth2 192
29. ce network with IP 172 16 3 0 netmask 255 255 255 0 shown in Figure 13 is used to connect to Tellur Windows and Mercury Linux machines As described before Mercury computer or any other Linux computer in office network can run the coordinator program to run the whole system process Tellur computer is the one that runs netAnalyzer and StreamAnalyzer programs CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 40 Centralized Control for a real time Ethernet Measurement System Mer cur yi Linux COORDINATOR 7 1 eth2 amp ee 7 5 gt 192 168 0 254 172 16 3 225 i eth3 192 0 3 1 Tellur Windows Aa 172 16 3 103 Figure 13 Office Network H1 netAnalyzer Measurement Card installed on Tellur machine eth2 etho peas 192 0 3 11 192 168 0 1 e G assist Westermo T Switch oe H2 g ethi Mercury Linux 192 168 0 2 COORDINATOR 7 te 192 168 0 0 eth2 ieee cthi 172 16 3 0 aree 192 168 0 254 172 16 3 225 eth2 192 0 3 12 eth3 192 0 3 1 ethi H3 192 168 0 3 Tellur Windows 172 16 3 103 eth2 192 0 3 1 4119 3 13 192 0 3 0 m m NetGear Switch 192 0 3 2 Figure 14 Complete Network Topology higher resolution version at Appendix B The complete network design is found in Figure 14 As you can see the router r0 is used to divide the network domains and connect them to each other A better resolution picture
30. configuration Create traffic generator click scripts according to the flow parameters defined in configuration files for hl and h3 e Connect to different computers such as traffic generators sink and capture stream Analyzer machines Start Stop sink program on computer h2 Start Stop traffic flows from h1 and h3 Start Stop capturing with NetAnalyzer card which is installed on Windows computer Analyse captured data by StreamAnalyzer on Windows computer Stop traffic generators and sink click scripts Transfer results numerical statistics and plots of the capture from Windows machine to coordinator machine The coordinator computer is decided to be a Linux machine in office network which is more convenient to start SSH connections from there to other Linux computers Also to make a connection to the Windows system an SSH server is required to be already installed and listen to SSH clients So the FreeSSHd application 5 1s used which provides the SSH server for Windows operating system In this way the Linux machine can make a connection to Windows system in order to execute the Capture and StreamAnalyzer programs remotely CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 34 Centralized Control for a real time Ethernet Measurement System Choosing best programming language architecture for the coordinator software The coordinator program is decided to be shell scripting because this progra
31. ction Socket programming will not be interesting for our project due that it would require start manually the server program previously wrote in C C in each machine waiting for requests and afterwards send messages to that servers in the coordinator We look for performing the control of the system in a centralized way interacting only with one machine in this case called the coordinator Due to this it is obvious that socket programming 1s not the best option and shell scripting fits more in our requirements Anther important point is the software maintenance extension in which we want to add some functionality or modify some part of the program In case of having socket programming it would be needed to modify the program in each machine due that for performing one task more than one machine 1s needed On the other hand in shell programming is not needed generally to modify the code in each machine interacting in the process in case of any desired change The control program is written in the coordinator and it includes all the actions performed for each computer first the connection with the desired computer and later on the commands executed for the remote computer Therefore it turns out that shell scripting is a better option in terms of system usage not needed any manual interaction with other machines and also in terms of maintenance and CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 35 Cen
32. d host MAC address which is used for transmission This is done directly by the main coordinator program placed at the office network Furthermore it is needed to invoke another expect subscripts which connect via SSH to the sink hosts placed in a different network measurement network and ping from there the traffic generator hosts This is executed by the subscript pingFromSink sh which receive as a parameter the IP address of the remote sink to connect with Finally the selected sink host will ping all the traffic generators machines Configure the Switch Next it runs a expect script which connects with the Westermo switch which 1s connected in the measurement network It will setup the configuration in the switch according to the parameters defined in a local file named switch param conf The expect scripts will read all the parameters from the file and it will intact with the switch sending the specific commands for interacting with the switch are defined in the Switch Management guide 6 adding the previous obtained parameters and waiting the interactive prompt answer from the device which indicates that the command have been received and it is possible to send the next one After this the program will wait during a short predefined time interval 2 seconds while the switch will be applying the previous configuration CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 36 Centralized Control for a rea
33. d is not designed to be able to connect through SSH or other communication programs it is not possible to program it in these ways The boards are connected through USB port to Windows machine which is used to download the program and also power it As it has been described once the program 1s downloaded into the boards they will be waiting for the reception of the SET and START message that will configure the flow and trigger the traffic generation In this way we use Java socket programming on the Coordinator side which communicate with the board on specified port sending the SET message containing the parameters and the START message On the board s side is used socket programming but in this case with C programming language due that the basic program provided for IAR for interacting with the boards is written in this language This java program reads the flow propieties from the file in which the user has written them sending the SET messages later on to each board CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 44 Centralized Control for a real time Ethernet Measurement System Final topology of the System After adding the CEC boards to the resulting topology is shown in figure 15 Here are highlighted the three different networks The office network contains the different machines PC and laptops that are used by everybody in the office It has been decided that the coordinator program the pro
34. e that the system does not guarantees that all the packets are schedulable the designer can make changes in the system modifying the links speed priorities and the topology until the schedulability is verified by TCN Analyzer This upper bound time is what users are interested to know in order to ensure and verify that their time critical applications in the network meet the latency requirements TCN Analyzer makes their prediction for Ethernet networks Nowadays most of time critical networks like the control networks in a car use CAN as a transmission protocol Nevertheless CAN has certain limitations as described It is considered in industry that most of the time critical applications using CAN will be replaced by Ethernet networks 9 10 TCN Analyzer pretends to be a verification tool for this promising technology taking advantage about the lack of applications that work in this field and the growing interest about using Ethernet networks in time critical systems such as in automation Facts which confirm the growing interest that industry put into this technology are the project performed by CPAC Systems company dependant of Volvo together with Time Critical Networks AB aiming to check the feasibility or replacing CAN with standard Ethernet 11 and the research groups of BMW that test the use of Ethernet in their systems BMW engineers tested the use of IP applications using Ethernet protocol to network automotive controllers i
35. e user has written the flows propieties it is possible to execute the system by running the file run sh in the same folder It is possible to run it by doing double click with the mouse on the file or executing it directly from the terminal In this last case will be possible to observe the out prints that the system generate which can help the user to make an idea which tasks are being executed in each moment and in which part of the system CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 46 Centralized Control for a real time Ethernet Measurement System When the execution has finished the results are available in the folder capture results in the desktop As it has been said the results of the capture analysis are provided in the folder capture results in which a different folder is created for each execution of the system Each folder is named with the date and time in which the execution has been done Applications Places system Z Osm GO guest Mon Sep 26 1 45PM f oo mal u St B File Edit View Places Help Computer G1L1U92Z9_ 154021 QL1U9Z5_ 155016 ULLU9Z5_1556U5 TCN TestFlows Coordinator ms guest s Home d110925_ 140146 d110925_ 140516 d110925_ 141624 d110926_114654 d110926_115028 d110926_134205 d110926_134256 capture_results capture_results v d110926_134256 selected containing 5 ite d110926_134256 Durat gt i TP iene
36. eady before generating the traffic Sleep 4 CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 62 Centralized Control for a real time Ethernet Measurement System Generate traffic trafficGenerator sh 192 0 3 11 auxTime amp trafficGenerator sh 192 0 3 13 auxTime amp broadcasts the START message broadcast sh TRANSFER RESULT TO LOCAL MACHINE mkdir resultDirectory transferResults sh 172 16 3 103 timestamp resultDirectory CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 63 Centralized Control for a real time Ethernet Measurement System CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 64
37. eply messages arrive to the router they will be delivered to the office network and to the coordinator computer avoiding any interference in the measurement network as it was expected separating the SSH control messages from the traffic in the measurement network CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 42 Centralized Control for a real time Ethernet Measurement System 3 5 Extend the architecture by adding CEC boards Add board traffic generators To extend the system to have different kind of traffic generators CEC boards which were used as CAN to Ethernet Converters are programed to be used as Ethernet traffic generators According to Ibrahim experiments that explained in 8 these boards can provide constant traffic flow where the Click traffic generators are not able to provide that Initially these boards were configured for generating CAN data traffic with 7 which was converted later on to Ethernet traffic This has been omitted in this project and we generate Ethernet traffic directly programming the cards through a special framework provided by IAR 20 Board specifications and Program The testing board is a development kit made by IAR Systems 21 It contains ARM based microcontroller LCD different kind of ports for different applications and USB port for download program on it and also provides power for the board The driver is compatible with Windows so the boards should be co
38. evious switch This is the basic architecture of the network created for the project start up and it has been improved and redesigned according to the project development 2 1 1 Traffic flow generation In order to generate the traffic flow in hosts h and A3 located at the lab network an external computer located at the office network mercury 1s used Through SSH in mercury we access to the hosts that generate the traffic flow The hosts in the lab network called as well measurement network use the open source project Click 2 a configurable software router developed and managed by a research group at a university in USA The TCN Click engine has been slightly improved with a custom C class that simulates the P stack of a normal computer When a Click script calls this class it can generate idealized bursts of maximum sized Ethernet packets corresponding to what large UDP frames would have been fragmented into by the IP stack of a normal computer These Click machines are unfortunately currently not good at producing flows of minimum sized Ethernet frames without substantial jitter The destination of the flows is the host h2 which is running the Click project and a script that counts the number of packets received from h and A3 This host provides the possibility of accessing to it through a own terminal keyboard and screen located in the lab network therefore it is not necessary access to it through SSH from the office network
39. fficient Each time the configuration file is changed the board program CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 43 Centralized Control for a real time Ethernet Measurement System should read the new parameters and download the code in every card which takes some seconds Furthermore this does not allow assign different flow propieties to every board So finally the followed approach in this project has been to download the program into the board just one time being listening for requests According to this way of proceeding different traffic propieties can be sent to different cards The cards will be waiting for a SET message which will set the flow propieties Later on it will wait for a START message which will trigger the flow generation As it has been described the program listen to the incoming messages forever and when it gets the SET message the card set up the flow configuration propieties according to the values received in the SET message Afterwards the START message is broadcasted to every board This is done in order to allow every board start sending messages simultaneously due that if the START message is sent sequentially the boards might be operating in different phase Integrating boards into the Coordinator Program The coordinator should be able to communicate with the boards in order to run the program and send the START message to start the traffic generation The car
40. from the GUI then the NetAnalyzer driver routine will start saving the capture measurement in the file C Default hea C Collect packets at sink host Host A2 is the sink node which collects all packets sent from A7 and A3 Host h2 is operated directly via the connected keyboard and monitor Therefore this needs a manual interaction with the computer A2 in order to execute the commands that will enable the sink click program which will receive and count the packets This steps include access to the Click folder where the next command have to be executed in order to start collecting the packets run the Click program that capture the packets click install root click sink_cec click CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 18 Centralized Control for a real time Ethernet Measurement System D Generating the traffic using Click Once that all hosts are accessible after setting up the routing tables and checking that all hosts are accessible using PING Mercury the host placed in the office network is used for accessing through SSH to the hosts hl and A3 traffic generators placed in the lab network Through Mercury computer placed in the office network we log on to h placed in the measurement network with the command SSH root 192 167 0 1 A1 IP address using the corresponding password Through SSH we access to the Click folder where we should execute the script FastUDPSource click This
41. g time The NetAnalyzer card has four interfaces as is shown in its GUI provided in the section 2 2 1 This can be observed here looking at the four arrows that have as a source or destination the NetAnalyzer card in Tellur host windows computer The first interface belongs to the flow that we pretend to measure in this case A7 So in this first step the packets that came from A1 are stamped with a time mark by the NetAnalyzer card and send back to the switch through the second interface Next interface the third one sends the packets coming from the switch back to the card where the messages previously tagged with a time stamp are detected and its forwarding time is calculated Finally the messages are sent to the sink or destination through the forth interface Once that all the different components of the system have been introduced the next step is to describe the procedure of obtaining the forwarding times which it includes generating the data flow how it is captured at the destination and how it is captured and analysed by Stream Analyzer after several format conversions by the different units describing the different inputs and outputs in this procedure This is by now done manually which automation 1s the aim of this master thesis CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 17 Centralized Control for a real time Ethernet Measurement System 2 1 2 Manual measurement procedure The setup
42. gram that controls the whole system can be installed in any machine connected to the office network Linux dependant This makes easier to use the system by different users at the office in their own computers It was decided to create a new network for sending the messages from the coordinator to the other hosts in the system for controlling and performing the different tasks of the system The main reason for a different network is to avoid having control messages interfering in the measurement network Finally the measurement network contains the different units that will create traffic and measure it It includes advanced switches a real time measurement card CEC boards that will generate traffic and certain hosts that can generate or receive traffic sinks 172 16 3 0 OFFICE NETWORK 192 0 3 0 CONTROL NETWORK 192 168 0 0 MEASUREMENT NETWORK Figure 15 Different networks interacting int he Measurement System CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 45 Centralized Control for a real time Ethernet Measurement System 4 Execution and Results The aim of the project has been to create a centralized control environment that allows the user to define the required traffic flows run the system and obtain the results of the measurement some seconds afterwards without being needed to interact manually with any other computer of the system Here is presented the developed tool resu
43. he results For this section it was defined a set of specific tasks to be done in order to overcome some issues e Avoid moving the capture file between computers 3 1 e Overcome the need of format conversions 3 3 e Avoid the need of interact with graphical interfaces GUIs 3 2 After the commitment of these tasks the main limitations for the automation of the system would be solved This will make possible to develop the coordinator program which will control all the tasks needed for performing and analysing a measurement B Provide a suitable system architecture define and develop the appropriate network architecture separating the control part from the measurement part CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems g Centralized Control for a real time Ethernet Measurement System 1 Introduction This section focuses on two different protocols used for transmitting into a communication medium from the point of view of time critical systems CAN and Ethernet 1 1 Finally it introduces TCN Analyzer tool related to the design and development of Ethernet networks 1 2 and it concludes explaining the purpose of the thesis work 1 3 1 1 Ethernet vs CAN in time critical systems Hosts need a protocol to define how to transmit into a communication medium being a bus a coaxial cable used for Ethernet or another technology These protocols handle how and when to initiate the transmiss
44. ilable nowadays that tries to solve these issues TCN Analyzer overcomes these restrictions TCN tool provides determinism to the standard Ethernet with latency jitter and packet drop guarantees CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 11 Centralized Control for a real time Ethernet Measurement System 1 2 TCN Analyzer tool TCN Analyzer tool is a tool developed by Time Critical Networks AB TCN s prototype design and analysis tool TCN Analyzer takes advantage of schedulability analysis theory for store and forward multi hop Ethernet networks 1 Instead of performing measurements on a network comprised of many switches and populated with many different flows TCN advocates the following approach to network design and analysis 1 Perform measurements on different types of components in the network in isolation 2 From these measurements create timing models that describe how the component behaves under different circumstance 3 Incorporate the timing models into TCN Analyzer were one can construct a complete network using virtual switches and flows and then compute upper bounds on the forwarding time of individual frames for example an UDP frame in a data flow sent from one host computer to another It allows the user to define a network adding virtual links flows switches and hosts where it is possible to define their timing propieties such as link speed or size of the flow packe
45. in this measurement are described in the Figure 3 In the next figure Figure 6 we see the traffic flow generated from h to h2 As it is noticeable the forwarding time is about 8 microseconds at the beginning because the other flow from h3 to h2 is not started yet So after a while the forwarding time increases It seems there should be some collisions and queuing at the switch because of the two flows h and h3 acting as a traffic generators and A2 as a sink and at the worst case it reaches about 15 microseconds Red 1 Green 3 a fettete ee oe eee Yee fesnsnenneenn Ce A ae E Eth packet TapA to TapB forwarding time us 0 1 2 3 4 5 6 Packet TapA capture time s Figure 7 Flow from h1 forwarding time The numerical statistics about forwarding time provided by StreamAnalyzer are as followed Forwarding time statistics maximumFT 15 2587890625 us averageFT 8 3169497884 us minimumFT 7 6293945312 us maxJitter 7 6293945312 us iBurstMaxFT 8849 iBurstMinFT 3763 iPacketMaxFT 0 iPacketMinFT 0 The analysis of the obtained timing results and parameters is out of scope CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 27 Centralized Control for a real time Ethernet Measurement System In Figure 8 is shown the plot that contains the serialization pattern at maximum forwarding time It shows up that certain packets from A1 and h3 are serialized at same time i
46. inIT 0 The analysis of the obtained timing results and parameters is out of scope CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 29 Centralized Control for a real time Ethernet Measurement System 3 Design amp implementation In this section are described the tasks needed for performing the automation of the system The aim is to have at the end of this section a software and an architecture including new networks and devices in order to obtain a centralized control for generating measurements and obtaining the results without more need of human interaction than the needed for executing this tool It should perform all the actions previously described in the distributed system for generating the traffic flows and provide the analysis results 3 1 Make StreamAnalyzer work on Windows After analysing the possibilities for automatizing the system we arrived to the conclusion that is better to have the program that captures the data and the program that analyses it in the same machine It will avoid unnecessary movements of files with considerable size However the issue is that the output file of the card containing the captured data generated in a window system have to be moved in a manual way to another computer running on Linux in order to be analysed by the StreamAnalyzer program which is compatible with Linux Systems To solve this we adapted the StreamAnalyzer program to work in Windows
47. ing Utility that uses ICMP protocol for testing the reachability of a host in the network e Python Programming language e Pylab numeric computation environment with plot functions e SFTP SSH File Transfer Protocol e ARP Address Resolution Protocol e MAC address Media Access Control Address e Switch Network device that connects networks segments e Driver Program that allows higher level programs to interact with a hardware device e Routing table table stored in a network device that lists the routes to network destinations e UDP User Datagram Protocol e USB Universal Serial Bus e TCN Time Critical Networks e TCN Analyzer TCN s product e StreamAnalyzer TCN s analysis program which obtains the timing results e IP Internet Protocol e LCD Liquid crystal display e C Programming language e C Programming language e Java Programming language e CEC CAN to Ethernet Converter e CAN Controller Area Network e GUI Graphical User Interface CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 54 Centralized Control for a real time Ethernet Measurement System 8 References 1 Bj rn Andersson and Jonas Lext Guaranteeing Hard Real Time Communications Over Standard Ethernet Networks 2 Eddie Kohler The Click Modular Router Ph D Thesis 3 Hilscher Gesellschaft fur Systemautomation mbH User Manual netANALYZER NXANL 50 RE 4 Hilscher Gesellschaft f
48. ins basic information of the capture such as the start time file number and data size which are useful to find out related capture files the sequence of files and where is the end of the captured data in file CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 32 Centralized Control for a real time Ethernet Measurement System Sequentially after the header part which 1s 32 bytes all the captured packets are placed until the data size is reached In this part the program should parse the packet It is noticeable that each packet is padded to 32 bits and it should be considered to calculate the packet size as it is not included in packet length Each packet has a header which contains the card port number packet length and the time stamp After the header part the packet fields should be extracted according to network headers structures like MAC header IP header and UDP header It should be mentioned that card driver such as packet header in big endian format and the data adds the network data and file header are in little endian format So it should be considered to convert the network format which is big endian The first 14 bytes related to MAC header are discarded and the following part is the IP header In this part due to the optional part of the IP header we need to calculate the size of the IP header including the padding to know where the UDP packet Starts Also the protocol field is important
49. ion in shared medium defining the properties in which data 1s transmitted and which measures are taken in order to provide reliable services such error detection or fault tolerance The Controller Area Network CAN is a vehicle bus communication protocol created originally for Robert Bosch in 1983 for the transmission of data in critical applications in which was required fault tolerance allowing microcontrollers and devices to communicate within a vehicle without the interaction of any computer It supports distributed real time control with a very high level or security 17 These are some of the most important CAN propieties e Priorization of messages e Guarantee of latency times e Multicast reception with time synchronization e Error detection and error signalling e Automatic retransmission of the messages that are corrupted e Fault tolerance management and confinement Defect nodes are switched off CAN is used mainly in automation and as well is being used in other sectors as trains or airplanes where fault tolerance and safety constrains are a major issue In order to achieve these powerful measures for error detection signalling and detection of faults are implemented in every CAN node It ensures that the message with higher priority is always sent when several units try to transmit at the same time This is called priority based bus arbitration where the flow with higher priority is allowed to transmit Other units which tr
50. is placed in Appendix B CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 41 Centralized Control for a real time Ethernet Measurement System Routing table setup Once the installation of the new network is done including the assignation of new IP addresses for the new devices it is needed to modify the routing tables of the different hosts involved in the transmission in order that the control packets are sent through the control network avoiding any control packet to interfere in the measurement going through the measurement network Especially since the routing table of the hosts traffic generators h and h2 only contains entries for the measurement network and for the control network some problem can happen to reply the requests from the coordinator placed in the office network When we connect through SSH from the coordinator computer placed in the office network the messages arrive to h7 and h3 as it is expected The issue comes with the reply of SSH packets in hosts h and h3 The office network is not defined in their routing table due that it contains only two one for the measurement network and one for the control network Therefore it is needed to set the default route route used when the destination is not defined in the route table as the router IP address of the control network interface This will force the reply of the control messages go through the control network Finally when the r
51. ject has been developed TCN Measurement tool It create traffic flows and measure the time it takes to the flows to reach the destination being able to compare the prediction done by TCN Analyzer with the real measurement performed by TCN Measurement tool At the end of this project it has been possible to perform a measurement just executing the tool developed in this project obtaining the timing results in few seconds On the opposite in the previous system version it was needed to execute manually several tasks on different computers and moving by manual methods the processed results between machines involved in the process This took several minutes for obtaining the timing results which TCN Measurement tool obtains in several seconds without needing any interaction except the execution of the start command To conclude comment about the good commitment of the development process It was planned to develop and perform the automation of at least one part of the measurement process and finally at the end of the project we achieved the automation of the complete measurement process CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 53 Centralized Control for a real time Ethernet Measurement System 7 Terminology and abbreviations This section explains different abbreviations and protocols used during this document 25 SSH Secure Shell Allows to access to a remote terminal in a secure way e P
52. ks LAN introduced in 1980 and standardized in IEEE 802 3 12 It provides better propieties such a higher data rate than CAN increased from 10 Mbits sec originally to 1000 Mbits sec Nevertheless Ethernet does not provide by itself fault tolerance or integrity services except allowing discarding corrupted frames if any is detected It just provides the service doing the best effort for it In case of some data is corrupted or does not reach the destination other higher level protocols such is TCP should be used for allowing a reliably transmission system In this case the length of the medium 1s not a problem being able to transmit up to very long distances CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 10 Centralized Control for a real time Ethernet Measurement System The main propieties to highlight about Ethernet are e Maximum bit rate 10 100 1000 Mb sec higher bit rates can be achieve with new technological improvements such as Gigabit Ethernet 13 e Source and destination for a message not only broadcast e Arbitration is destructive if more than one node transmits at the same time no useful data can be recovered In industry there is interest in find out the actual capacity reliability and usability of Ethernet Networks in the industrial control area The article authored by Jeff Nowling Industrial Automotion Engineering Consultant 18 focuses on this questions how fast is p
53. l time Ethernet Measurement System Create Click scripts that generate traffic on hl and h3 In similar way than the previous step in this part it is executed a expect script which connects to the traffic generators machines and h3 through SSH moving to the correct folder where are placed the click scripts that generate the traffic once they are being executed Next it will read as before the parameters from a predefined file named traffic _configl conf and traffic_config3 conf which contains the parameters that define the characteristics of the flow that have to be generated for the hosts h and h3 respectively In short it contacts with the machine A and h3 where it writes down the desired click script which will be executed later in order to generate the traffic flows This SSH connections with hI and h3 to do the described work are done in parallel traffic generator CEC boards set up Added in point 3 5 as a new functionality In an initial step in this point we were connecting through SSH to the windows computer which has connected the boards and downloading the board s code each time into the boards after reading from a file the propieties of the desired flow This was considered as a non practical way of proceeding Therefore this procedure was redesigned not being needed to read from any file the properties of the desired flow and not being needed to download the traffic into the card each execution time To achieve this
54. line the number of received packets from 3 In order to turn off Click after using it the next command can be executed click uninstall CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 19 Centralized Control for a real time Ethernet Measurement System G First Format Conversion NetAnalyzer s driver stores the capture file in a propietary format a binary file with hea extension Next step is to convert the format to pcap 14 using the option Convert in the menu of the application provided by Hilscher Figure 4 The same application GUI allows to start stop a capture and convert the resulting file to pcap a format that is readable by Wireshark 15 This new file in pcap format can be readed with Wireshark which shows all the captured packets during the measurement H Second Format Conversion To analyse the measurement with Stream Analyzer the previous file in pcap format must be translated to csv format This 1s done by the option Export file at the graphical interface of Wireshark Figure 5 This csv format is more readable from a human point of view and it is the format used by Stream Analyzer program developed in C by Jonas Lext in order to process the capture and obtain the timing results such as the maximum forwarding time that we are interested I Move capture files to a Linux machine that runs Stream Analyzer Once this last format translation is done the resulting file con
55. lt of this project In Figure 16 is shown the system interface The coordinator program that will launch the measurement consists of two folders All the files that are the heart of the system are placed in the Coordinator folder which includes the main program and all the secondary scripts created in order to perform specific functions The user just need to access to the folder called TCN TestFlows renamed later on to TCN Measurement tool where there is a text file in which the user needs to define the flows to be generated and their propieties Applications Places System A Om O guest Mon Sep 26 1 44PM df Computer TCN TestFlows Coordinator 4 File Edit View Search Tools Documents Help Sm amp fa New Open Save Print ndi edo Cut Copy Pasti Find Replace Cap_0_flowParam txt 9 Duration 20 IP PERIOD us PACKET SIZE bytes ethernet Proiority sink delay Active Y N 10 140 750 7 1 0OY 20 60 750 4 2 OY 30 140 2940 2 OY capture_results TCN TestFlows File Edit View Places Help Durat 1P h Cap_0_flowParam txt Be an j have Instructions txt TCN TestFlows v run sh selected 83 byt 1 e gue guest Ga Dro GH tcn_ Moz gue Ten Tim Ea TCN amp Cap cap d11 Bla Figure 16 TCN Measurement tool execution environment Once th
56. m hl count count from _h3 count NetAnalyzer on Tellur Tellur is the Windows computer with the Hilscher NetAnalyzer card installed e Start the application NetAnanlyzer from the Windows Start Menu e Ensure that all tap ports are active e Start NetAnalyzer measurement by clicking Start e Start the packet generator scripts see below Source h1 By running the click script through the bash script run source we can avoid the SSH connection hanging forever This script uninstalls the click script after 30 seconds after it finished running On h1 drive click install FastUDPSource click On h3 drive click install FastUDPSource click CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 57 Centralized Control for a real time Ethernet Measurement System Start at NetAnalyzer then convert double click the file to start wireshark e Wait until all enough packets have passed Press Stop e The NetAnalyzer driver routine now saves the measurement in the file C Default hea e Press Convert in NetAnalyzer GUI to translate this file to the format pcap with a suitable filename e Double click the new pcap file This will start wireshark which shows all the captured packets during the measurement e In order to allow StreamAnalyzer to process the capture file we must translate the file again to the format csv Comma Separtated Values In wireshark select File Export File Enter the same filename as the p
57. m is mainly connecting and executing commands on different machines which is simpler to handle this process in shell scripts where it 1s possible to execute commands directly Furthermore expect scripting which is explained in 5 is useful for interacting with connected systems and execute programs through the SSH and SFTP connections remotely without manual interaction For instance when we create a SSH connection the user does not need to type the password manually because we can expect the system is requesting the password and send it automatically In other words the different outputs of the system can be expected and replied according to that specific output automatically In this way there are several expect scripts that are used for connecting to other machines through SSH or SFTP in other words connecting through some interactive protocol One the other hand there is several bash scripts in concrete the main program is a bash script which execute commands in the local machine and also other scripts such as the expect scripts that contact remotely with other machines and also executes another bash scripts that execute some sequences of commands for a same functionality like updating the local routing table In this case shell scripting is a better option for our project than another alternative approaches such as it could be socket programming in which a program should be written in each machine listening in one port for performing an a
58. n the engine control unit founding that P Ethernet could suit well the real time requirements even for safety critical applications It 1s considered that modern cars incorporate over 70 embedded computers networked by a host of different systems Automotive industry turns their attention to Ethernet as a common backbone for the car network offering an important simplification of the automotive networking jungle 9 In conclusion it is predicable that Ethernet will be the transmission protocol used in a not so far future in time critical applications which use CAN nowadays Most of the tools currently available for verifying the timing constraints and correctness of the networks used in time critical applications are developed for CAN networks Therefore TCN Analyzer which is a tool for designing and verifying the timing correctness in Ethernet networks has chances to be a successful tool for the usage of Ethernet networks in this field as described where there is a lack of products that deal with Ethernet in time critical network analysis CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 13 Centralized Control for a real time Ethernet Measurement System 1 3 Purpose of Thesis Work The aim of this thesis work is not related directly with the main tool previously described TCN Analyzer However this project focuses on designing and implementing a Centralized control for a real time Ethernet Measurement S
59. n this period and that seems to make a collision which might increase the forwarding time in the switch Red 1 Green 3 4 592 4 594 Packet TapB capture time s Figure 8 Serialization pattern at max forwarding time interval In this plot is possible to observe in which time instant are delivered the packets of each flow at the maximum forwarding interval time As it is shown in the figure 3 which illustrates the flow generation there are two flows generating traffic host A7 whose packets are captured in red colour and host 43 whose packets are captured in green colour All of them have as a destination host h2 CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 28 Centralized Control for a real time Ethernet Measurement System Figure 9 contains the plot in which is observed that there is not constant delivery of packets and the jitter varies Red 1 Green 3 Eth packet TapA to TapB forwarding time us 2 84 2 686 2 688 2 690 2 692 2 694 2 696 2 698 Packet TapA capture time s Figure 9 Jitter at max inter arrival time period Finally StreamAnalyzer program provides numerical results about jitter timing analysis Computing forwarding times TapA stream interarrival time statistics maximumlT 988 2450103760 us averagelIT 493 4716271237 us minimumIT 107 0499420166 us maxJitter 881 1950683594 us iBurstMaxIT 4996 iBurstMinIT 108 iPacketMaxIT 0 iPacketM
60. nnected to Windows machine Tellur in our system To program the boards the project is designed to assign specific IP to each board and to be ready to send the UDP traffic when required So the board is listening on a port to incoming packets and if it gets the UDP packet contains START message the board starts the UDP traffic IAR Systems provides a basic program for interacting with the board and providing a basic functionality This program is written in C C and was modified to be a CAN to Ethernet Converter by Ibrahim which is used in his Master thesis 8 but it this project it is set to send UDP traffic with out CAN interaction and also we adapted it according to our project requirements According to our modification the traffic configuration is not specified in the code so it can be given according to each traffic specification and network design There were two approaches to do this step First the traffic specification parameters could be read from a file with the board program In this way the coordinator computer should edit the configuration file and transfer it to Windows machine allowing the board to read the parameters from the file In second approach the flow parameters are sent in a UDP packet with SET message In this way the program can set the traffic according to the parameters before generate the traffic being needed to download the code into the board each execution time The first approach is not e
61. nt Card Interface GUD The filter settings can be used to accept or reject packets from special source and destination MAC addresses The settings can be saved and used later as well There exist two analysing options one is for capturing packets and save them on the hard disk so they can be used later to analyse the time and other features The second option is the timing analysis In this project as mentioned in section 2 1 we are going to estimate the Forwarding time in the Switch so we use the Capture Data for capturing every packet being stored later into a file which we convert to pcap format to use it later in Wireshark and get the timestamps of the packets before and after the switch CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 23 Centralized Control for a real time Ethernet Measurement System 2 2 2 Wireshark Interface Second file conversion process Next figure shows the graphical interface of Wireshark program that is needed in order to perform the second file conversion process The first conversion process is done through netAnalyzer GUI shown in Figure 4 as described It converts the capture file from hea format to pcap format understandable by Wireshark Finally in this second conversion process using Wireshark the pcap file is converted to csv format as it is shown in Figure 5 which is readable by StreamAnalyzer concluding the file conversion procedures G00 NT
62. nternet and to run the measurement program The measurement network with IP 192 168 0 0 netmask 255 255 255 0 contains the netAnalyzer card Westermo switch and hl h3 and A2 hosts on their first network interface cards which is connected to this network This part of network design is shown in Figure 11 So the traffic generated by A and A3 to h2 are the desired flows which will be captured by measurement card in this network ae netAnalyzer Measurement Card ra installed on T llur machine eth2 etho ge A e a 192 0 3 11 192 168 0 1 eS ie rmo Thdustrial 1 168 0 25 h 192 168 0 0 eth2 192 0 3 12 ethi H3 192 168 0 3 Figure 11 Measurement network CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 39 Centralized Control for a real time Ethernet Measurement System On the other hand the control network with IP 192 0 3 0 netmask 255 255 255 0 is supposed to be used by the coordinator to connect to different machines and run the control commands through this connection This network also contains h h3 and 42 but with their second network interface which is assigned to 192 0 3 0 network In this way the control flow is not passing through the switch of measurement network and won t make any interference in the measurement process eth2 192 0 3 12 ethi H3 192 168 0 3 eth2 192 0 3 13 192 0 3 0 Figure 12 Control Network The offi
63. ossible to communicate via Ethernet the effects on reliability and determinism This article highlight that a good network throughput depends on the network design bit rate speed in which data is transmitted and remains in the network and other devices used in the network Nevertheless it concludes that a properly planned and installed Ethernet network should be capable of providing fast reliable and deterministic transmission of data in industrial control applications There are many reasons for adopting Ethernet standard in these applications 18 e Ethernet is nowadays a technology very widespread operating in reasonable good costs e It has a good performance in terms of bandwidth and bit rate transmitting big amounts of data at high speed e Interoperability and convergence It allows multiple services on a single cable e Standards well widespread and adopted It would bring the advantage in interacting with another systems or networks due that most of them operate in Ethernet no conversion system would be needed On the other hand industrial Ethernet would be lacking certain propieties that are significant for industrial applications These are e Guarantee that frames are transmitted within a certain time bound latency e Fault tolerance and redundancy mechanisms that act when a unit fails e Determinism always is predicted the same results certain circumstances there are not undefined status New technology is ava
64. r ub 100 fw 70 sas lt scriptfile gt sas lt measuredfile gt csv The scv file contains the captured flow and the script file sas contains the instructions of the desired analysis This script tells the StreamAnalyzer about what we are looking for and which graphs are desired Basically we are looking for these features e Forwarding time for the Ethernet packets from TapA interface 1 and 2 of the NetAnalyzer card to TapB interface 3 and 4 e Serialization of the packets from hl and h3 at the maximum forwarding time in TapB e Maximum inter arrival time The difference in inter arrival time causes the jitter delay So we are looking for the flow behaviour when this inter arrival time increases A current bottleneck is that the file produced by the measurement card must be converted manually twice first from the propietary Hilscher binary file format into the pcap binary format Then again from pcap to csv which is a simple text based format Finally StreamAnalyzer reads the text file after being moved manually to a Linux machine in which StreamAnalyzer can be executed Hilscher documentation should explain the structure of the Hilscher binary file format so StreamAnalyzer should be able to read this format directly in an advanced stage of the project CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 21 Centralized Control for a real time Ethernet Measurement System 2 2 Different In
65. rement System 2 3 Scenarios and examples of measurements This section contains one predefined scenario for a measurement According to the parameters defined the data flow is generated in the network After all the measured data is analysed by StreamAnalyzer Plots and numerical statistics are generated providing the timing results of the analysis 2 3 1 Scenario 1 These are the parameters for the packet flow generation which define flow propieties as size of the traffic packets generated and amount of traffic to generate Limit 100 000 MAC O 00 0C F1 CD 42 BE SINK 192 168 0 1 Frame size 1500 MAC D 00 11 11 0E 7E 80 DstlIp 192 168 0 2 DPort 1500 Checksum true This data is stored by a Click program which creates the desired traffic Once the previous click program is executed for generating the traffic the packet capture is started by pressing the button Start in the Measurement Card s GUI presented in the previous point The resulting file containing the capture needs of several format conversion processes until the file is in csv format Finally it is analysed using StreamAnalyzer obtaining the following results plots with the forwarding time and numerical statistics The analysis of the timing and traffic parameters is out of scope CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 26 Centralized Control for a real time Ethernet Measurement System The hosts involved
66. retends to be leader in the promising technology of using Ethernet in time critical applications such automotion and controls for vehicles Next there are three products that try to solve same or similar problems than TCN Analyzer e Symtavision 22 e INCHRON 23 e Real Time at Work RTAW 24 CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 51 Centralized Control for a real time Ethernet Measurement System However they use different techniques like simulation instead of worst case response time analysis that is used in TCN Analyzer In the case that they use the same technique they are targeting CAN networks and or task scheduling in ECUs Electronic Control Units in vehicle networks instead of Ethernet As it has been described in section 1 TCN product TCN Analyzer focuses on creating a network model by means of an interactive GUI being able of performing afterwards the analysis and prediction of the timing constraints of the virtual Ethernet network created Many companies and institutions are already showing interest about adding Ethernet to their time critical systems creating research projects in order to validate that standard Ethernet can be used in this time critical applications without major changes In fact as described in section 1 research project of BMW conclude that IP Ethernet could suit well the real time requirements even for safety critical applications 9 Furthermore TCN
67. sented before according to the traffic defined at the TCN Analyzer tool and performs a timing traffic analysis The goal of this is to compare the timing prediction provided by the TCN Analyzer tool and the timing results obtained with the TCN Measurement tool in order to be sure that TCN Analyzer tool provides an adequate time prediction that customers can trust Therefore TCN Analyzer is a tool that provides a prediction of the maximum forwarding time in which the packet flows are delivered to its destination For performing this action TCN Analyzer takes in consideration worst case response time analysis More information about the TCN Analyzer tool and the algorithms used for calculating the maximum forwarding time can be found at Meng s Master thesis 19 CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 50 Centralized Control for a real time Ethernet Measurement System 5 Future Work Every system is always ready for improvements or new tasks and functionalities that could complement it This system is not different and several improvements and new tasks have been performed at the last period when the systems seemed to be already finished One point to make improvements is to achieve major integration of the TCN Analyzer with the TCN Measurement system As it has been described TCN Analyzer performs a prediction of the worst forwarding time after the user has created in their graphical interface the
68. strial Switch 192 168 0 253 192 168 0 20 192 168 0 30 netAnalyzer Measurement Card zrk installed on Tellur machine IAR CEC Traffic generator boards 192 168 0 10 Figure 22 network toplogy view 3 CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 61 Centralized Control for a real time Ethernet Measurement System Appendix C Coordinator Program Next it is shown the code of the main script in the coordinator program which calls different modules for providing the desired functionality Define variables capturing Time 30 aux Time capturingTime 6 timestamp date y m d _ H M S resultDirectory HOME Desktop d timestamp add entries to local routing table routingTable sh ping to the different hosts involved in the process pingFromSink sh 192 0 3 12 local pings not included Configure the Switch switch sh 192 168 0 253 sleep 2 Create Click scripts on h1 and h3 reading the parameters from trafficConfig1 3 txt createScript sh 192 0 3 11 traffic _configl conf amp createScript sh 192 0 3 13 traffic_config3 conf amp wait Set up traffic generator boards reads from file flow param and send SET java UDPClhient Start sink sink sh 192 0 3 12 auxTime amp Start capturing packets in NetAnalyzer measurement card windows machine capture sh 172 16 3 103 timestamp capturingTime amp Make sure the capturing and sink programs are r
69. t system which are the different units and how they interact between them defining the interfaces and describing the different tasks that needed to be done for performing a measurement 2 1 System Overview The development of this project takes place in TCN s office where a private lab network also called measurement network separated from the office network have been created exclusively for the project development Next figure Figure 2 shows the network topology 192 168 0 10 192 168 0 10 tellur NetAnalyzer 00 00 00 00 00 01 RedFox 192 168 0 253 TapA Port0 TapA Port1l TapB Port0 192 168 0 3 192 168 0 2 00 00 11 11 0E 7E 80 NetGear DLink e 172 16 3 225 00 1B 21 00 B4 09 192 168 0 254 00 11 11 18 E1 ED 192 0 3 1 eth0 00 1B 21 01 86 0A Figure 2 network topology CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 15 Centralized Control for a real time Ethernet Measurement System The router RO is the gate that separates networks the lab network with interface eth2 and the office network with interface ethl To ethl is connected the router DLink that provides connection to all hosts in the office network On the other hand eth2 is connected the Redfox switch to which are connected the different hosts h1 h2 h3 used for generating and collecting the packets and the real time NetAnalyzer card which measures the packets forwarding time in the pr
70. taining the measurement have to be moved using some manual method such as mail or Dropbox to another Linux machine that runs the Stream Analyzer using the captured data in csv format for performing the forwarding time analysis One of the aims of this project is to avoid such format transformation and file movement from different hosts in order to perform the system automation J Analysing the measurement with Stream Analyzer After obtaining the measured data from the Measurement card it is time to analyse the data and find out about the desired features of the flow like the forwarding times in the switch This is done by StreamAnalyzer program which is a C program which runs only in Linux machines So after the capture file is obtained several format conversions are done obtaining finally the csv file which is readable by StreamAnalyzer Now we can use StreamAnalyzer in order to classify the packets and separate them into different applications flows depending on protocol source and destination address etc Furthermore it can compute the forwarding times of the packets that passed the two taps of the measurement card and can produce different types of plots CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 20 Centralized Control for a real time Ethernet Measurement System In this way the StreamAnalyzer program use two files when it runs The command to run the StreamAnalyzer 1s streamanalyze
71. terfaces 2 2 1 Real Time Ethernet Measurement card Interface To capture streams of Ethernet packets we use a NXANL 50 RE measurement card from Hilscher 3 The card passively analyses the data in a network communication link and captures the incoming Ethernet frames Before sending each captured frame to a file on the hard drive the card inserts a time stamp with nano second resolution into the packet header By tapping the Ethernet packets just before they enter a switch and again as soon as they leave the switch it is possible to compute the forwarding time of the packet through the switch The data capturing process must be configured and started via the NetAnalyzer software that comes with the card and which is installed on a Windows XP PC However from Hilscher we have acquired documentation that briefly explains what functions are available in the card driver that is residing on the machine This documentation should be enough to be able to call the driver functions from a custom developed application Thus it should be possible to write an application that allows remote starting and stopping of a capturing session Currently analysis of the captured stream is done off line using the application StreamAnalyzer discussed in the next section The interface which is used for the measurement card is called NetAnalyzer software There exists a graphical interface shown in Figure 4 This is used to start and stop capturing packets and also
72. time it takes the system to deliver the packets These results can be observed as well in a statistics file that includes some extra information Applications Places System lt A WO O guest Mon Sep 26 1 47PM d m Cap_0_fwd_tm_ti_2 467700_s_is_0 01250 File Edit View Search Tools Documents Help 2 Edit View Image Go Help File Edit View Image Go Help D a amp 8 gt Q Q l Q 4 gt g New Open Save Print vious Next In Out Normal Fit Cap_O statistics txt 9 s Previous Next In Out Red 30 Green 20 a Red 30 Green 20 r m 2 TapA stream interarrival time statistics maximumIT 131 6070556641 us averageIT 130 7188795181 us 100 minimumIT 130 1765441895 us maxJitter 1 4305114746 us iBurstMaxIT 1984 j iBurstMinIT 2265 iPacketMaxIT 0 iPacketMinIT 0 Eth packet 8 Forwarding time statistics maximumFT 89 4069671631 us averageFT 39 1758439946 us 20 WURA minimumFT 26 2260437012 us 800 x 600 pixels 32 2KB 41 maxJitter 63 1809234619 us ibursttaxrT 4341 A e epee iBurstMin a i iPacketMaxFT 0 52 j j i iPacketMinFT 0 File Edit View Search Tools Documents Help Fils Edit View _ imags So Hain y a RDA A a aa A S A A g R v v Previous Next In Out Normal Fit Left Rig New Open Save Print Cap_O flowParam txt 3 Red 30 Green 20 Du ration 20 Z IP PERLOD us
73. ting files to a folder named with the current data year month day time 1n in which the capture was made CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 37 Centralized Control for a real time Ethernet Measurement System Make sure the capturing and sink programs are ready before generating the traffic In this case it has been decided to wait during some seconds to make sure that the NetAnalyzer measurement card and the Sink machine are ready for receiving packets Generate traffic flows in H1 and H3 Next it is run a expect script which connects to the traffic generators machines H and H3 through the specific control interface in the Control network for avoiding another packets interferences in the measurement network The expect script that contains this functionality is named trafficGenerator sh These two connections with HI and H3 are done in parallel Generate board traffic Added in section 3 5 as a new functionality In this case it was requested to generate simultaneously traffic in every board It implies that every board receives the START message at the same time instant To achieve this 1t connects through SSH to one machine connected directly to the measurement network in this case Mercury From this machine it 1s broadcasted the START message which will be received for every card and the traffic generation will start Done in subscript broadcast sh Transfer results to local machine
74. tor Flow Editor New Host New Bridge New Link e x Network Topology Host Editor amp Switch Editor Link Editor 6 amp Frame Template Edi amp Flow Editor D K Name Model Property Value Name Connector Name Protocol Property Value Host1 Host gt Name Redfoxl L1 Host 1 Port NewfFra UDP gt Name NewFlow Host2 Host gt Name Redfox2 L2 Host3 Port NewFra UDP gt Name NewFlow0O Host3 Host L3 Redfox1 P NewFra UDP gt Name NewFlowl Host4 Host L4 Redfox2 P L5 Redfox2 P gt gt gt Figure 19 TCN Analyzer GUI Figure 19 shows a non final version of the TCN Analyzer GUI in which it is possible to define the network propieties here it is shown that four hosts have been defined and two Redfox switches The traffic characteristics have been defined in the lists above the picture When TCN Analyzer performs the analysis it predicts the maximum forwarding time in the worst case This is what companies and potential customers using the TCN Analyzer tool are interested in CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 49 Centralized Control for a real time Ethernet Measurement System Goal of the comparison On the other hand the aim of this thesis has been the development of the Centralized Measurement Control described in previous sections The centralized measurement tool developed in this project TCN Measurement preforms measurements in the Distributed System pre
75. tralized Control for a real time Ethernet Measurement System programming in which the main code that control the global interaction 1s placed in the coordinator program Next it is shown a list of tasks which are executed sequentially in the main script that runs all the different components needed in the system for providing the desired functionally Define variables Define local variables that will be used in subscripts like time stamp for creating the folder with results named with the current data year month day time Also some predefined directories are written in this part add entries to local routing table Here it is executed a bash script which need to login as a root for executing the commands for updating the routing table It will add the necessary entries for finding the measurement networks and the control network in every machine of the office network where in which is executed this program As it has been commented before the only prerequisite is to use a Linux machine for running the coordinator program which is obviously due that the coordinator program is written in shell scripts This is done with the bash script routingTable sh Ping to different machines involved in the process Here the program will ping the different machines involved in the process in order to update the switch and router entries It will avoid to have later on ARP messages in which is trying to bind the requested IP address with the desire
76. tributed System Centralized Control for a Real Time Ethernet Measurement System FERNANDO FERRI VIDAL FERNANDO FERRI VIDAL October 2011 Examiner JAN JONSSON Supervisior JONAS LEXT Co worker FATEMEH AYAT Chalmers University of Technology University of Gothenburg Department of Computer Science and Engineering SE 412 96 Goteborg Sweden Telephone 46 0 31 772 1000 Department of Computer Science and Engineering Goteborg Sweden October 2011 Abstract TCN Analyzer is a design and analysis tool that allows the user to create a model of a network to be analyzed It provides a prediction of the maximum forwarding time in the network for a concrete flow and some other properties such as the guarantee of non packet drops The development of TCN Analyzer is still in a stage where it is needed to verify that the mathematical formulas used in the schedulability analysis make correct predictions about the forwarding times of each frame In order to verify the predictions at the start up of this project the company had a manual measurement procedure formed by several manual tasks It needs to be automated and improved in this project Finally at the end of this project a centralized entity that automate the measurement system is developed successfully allowing the user to obtain the timing results just by executing the developed measurement tool Keywords Distributed System Ethernet Measurement System Time Critical applications
77. ts The GUI of this program is shown in Figure 1 where are defined four hosts and two Redfox Switches all together with the links that connect the network and the flow definition LI File View Analyze Help Host Editor Bridge Editor Link Editor Frame Template Editor Flow Editor New Host New Bridge New Link Network Topology DEE Host Editor amp Switch Editor amp Link Editor a Frame Template Edi amp Flow Editor DRE Name Model Property Value Name Connector Name Protocol Property Value Host1 Host gt Name Redfox1 L1 Host1 Port NewFra UDP gt Name NewFlow Host2 Host gt Name Redfox2 L2 Host3 Port NewFra UDP gt Name NewFlowO Host3 Host L3 Redfox1 P NewFra UDP gt Name NewFlow1 Host4 Host L4 Redfox2 P L5 Redfox2 P Figure 1 TCN Analyzer GUI CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 12 Centralized Control for a real time Ethernet Measurement System Once the virtual network is created and their propieties are set up the program will be ready for performing the timing analysis This timing analysis which is the aim of this tool provides an estimation of the maximum time needed for a packet or a flow to reach their destination TCN Analyzer calculates an upper bound of the transmission delay or the maximum forwarding time The tool makes a prevision of this upper bound time and guarantees that any packet of the flow do not exceeds this estimated time In cas
78. ur Systemautomation mbH Driver Manual netANALYZER API Windows 2000 XP Vista 7 V1 3 5 Expect homepage http expect sourceforge net 6 Westermo OS Management Guide RedFox Series Wolverine Series 6101 3201 Version 4 2 0 1584 1 7 PCAN View http www peak system com Product Details 49 M5d3 lea5c82c 0 html amp L 1 amp tx_ commerce _pil catUid 10 amp tx_ commerce_pil showUid 32 8 Mohammad Ibrahim Ethernet in Steer by wire Applications M Sc KTH Royal Institute of Technology July 2001 9 Industrial Ethernet advisory group http www industrial ethernet org ethernet protocols technologies a universal network for in car control systems 10 Wilfried Voss President esd electronics Inc USA The Future of CAN CANopen and the Industrial Ethernet Challenge http www rtcgroup com whitepapers files TheFutureofCAN pdf 11 TCN news post http www timecriticalnetworks com index php option com_content amp view article amp id 4 amp It emid 5 12 Ethenet standard IEEE 802 3 http standards iecee org about get 802 802 3 html 13 Gigabit Ethernet http www cisco com en US tech tk389 tk214 tech_brief09186a008009 la8a html 14 Pcap file format http www fileinfo com extension pcap 15 Wireshark tool page http www wireshark org 16 Workshop event http www timmo 2 use org events OpenWorkshop201 1 html 17 CAN protocol http www can cia de fileadmin cia specifications
79. ystem which will provide the tool software and the infrastructure networks needed for performing the verification of the timing predictions provided by TCN Analyzer It pretends to be an automatized measurement system where the results could be obtained with the minimum user interaction A measurement system was available at the start up of this project nevertheless this measurement system needed of several tasks to be done sequentially in order to perform a single measurement These tasks were manual including interaction with different computers where the data obtained in a computer needed to be sent manually to another computer in order to perform the next task in the same single measurement Furthermore these tasks included interaction with GUIs graphical interfaces with mouse usage and help of some externals programs for converting some files to another format This procedure made the measurement not user friendly a difficult process and not really efficient to obtain measurements where it could take several minutes to perform the set of manual tasks for a single measurement Next section gives an overview of the TCN s initial measurement system and its individual components CHALMERS Computer Science and Engineering M Sc Networks and Distributed Systems 14 Centralized Control for a real time Ethernet Measurement System 2 Pre study phase The aim of this section is to provide a big picture about the initial measuremen

Single point of Control for a Distributed System

Contents

Download Pdf Manuals

Related Search

Related Contents