User Controlled LightPaths
Contents
1. gt Select E Marquee Topology Tool IES Network Elements A E cisco ONS 15454 TS Nortel OME 6500 F Nortel HDXc eee E Ten Figure 3 Physical Network Editor letting UCLP know about NE s and links means a telnet session is being set up between UCLP and the OME s and cross connects are being set using TL1 commands By setting the cross connects a lightpath is created 5 3 Issues We have been installing UCLP version 2 0 on both Windows and Linux It had been tested on Windows and the GUI currently is available as a Windows executable only However all the back end software can be installed on Linux without problems see Appendix Halfway our research we were given a pre release of UCLP version 2 1 The upgrade was seamless on both OS s At the same time we got version 2 1 our network administrator removed some wrong settings in the OME s in our testbed We didn t try to deliberately re misconfigure the OME s to test version 2 1 for this Therefore sometimes we couldn t tell whether a problem has been solved by the upgrade or because of the removal of wrong OME settings This is an incomplete list of issues we encountered It should give a rough idea about the development status UCLP currently is in e Version 2 0 sometimes hang when creating LP WS s No meaningfull error message other then a socket timeout after about 5 minutes This problem disappeared after the OME cleanup and install2. 11 6 2 Similarities Both UCLP and DRAC are designed around the concept of web service ori entation Both systems use Java technologies and existing standard toolsets to achieve this This can make them portable and extendable Neither of them is in production use today yet Both are meant to be used by end users offering them a way to control lightpaths without the need to contact a service provider by mail or phone every time 6 3 Differences The main differences between DRAC and UCLP spring from their respective design objectives DRAC offers a way to schedule single lightpaths Bandwidth is guaranteed but the topology of the network isn t UCLP offers the user or some user process a dedicated APN He can activate and de activate multiple scenario s at will This way he can change back and forth network topologies Disabled resources will keep being available to him exclusively DRAC supports VCAT automatic pathfinding and scheduling It is possible to implement these capabilities in UCLP but this is something not yet done These are not among UCLP s main objectives Using DRAC is a means of making optimised use of bandwith which is a financial benefit UCLP holds the concept of multiple layers of services which can be delegated and subdelegated DRAC doesn t Any APN administrator can make part of his resources available to another user In UCLP the use of Super Lightpaths provide a way to hide internal netwo
3. admin with an empty password didn t work Searched the web for it and found this thread on a java sun com forum I edited in stall_workdir apache tomcat 5 5 20 conf tomcat users xml to give the tomcat user extra rights lt tomcat users gt lt role rolename tomcat gt lt role rolename rolei gt lt role rolename manager gt lt role rolename admin gt lt user username tomcat password tomcat roles tomcat admin manager gt lt user username both password tomcat roles tomcat role1 gt lt user username role1 password tomcat roles role1 gt lt tomcat users gt Note that the tomcat user has a non empty password Login now succeeded The rest of this step succeeded without any modifications to the original installation instructions Configure BPEL Engine for Persistance OK without modifications See URL http forum java sun com thread jspa threadID 596489 16 Configure BPEL Engine I got a java nullpointer exception when updating Restarted tomcat and succeeded unstable Installing UCLP BPEL services OK without modifications Install a LDAP server and a LDAP browser Openldap does not provide precompiled packages Debian does but we are trying to avoid all system wide installations Got openldap 2 3 32 sources from openldap org configured for installation in install_workdir ldap and com piled installed configere aprefix make dep
4. supported by the UCLP software Thanks to the developers of i2CAT who included support for this card in a short time frame The open standards used in UCLP v2 offer great extensibility however source code and API aren t available yet Another application that offers the user great flexibility in creating their own lightpaths is Nortel s Dynamic Resource Allocation Controller DRAC These two applications are very similar exept for the fact that UCLP is offering resources in a more abstracted way which reduces the complexity integrating UCLP in applications Future work would hopefully include e the release of the source code and the API e a pathfinding module so that an user can create a lightpath between two endpoints without having to worry about the resources in between e VCAT support 8 Acknowledgements First of all we want to thank Ronald van der Pol and Andree Toonk by guiding us this project In such a short time frame we couldn t have managed it without them Secondly a big thanks goes to SURFnet who provided the testbed Also we would like to thank Eduard Grassa i2CAT foundation and Scott Campbell CRC for fixing bugs and adding hardware support on the fly answering our questions and providing us with the pre release UCLPv2 1 Furthermore we thank Bram Peeters and Victor Reijs to share their view on both DRAC and UCLP with us It turned out to be very useful And thanks to Paola Grosso and Paul Wielinga for their fe
5. UCLP did not support the DWDM cards in the Nortel 6500 However the developers sent us a simple patch that solved this Once when setting and unsetting a scenario in version 2 1 a link disap peared in the Physical Network Editor We had to remove the APNs and WS s before being able to recreate the link Once in version 2 1 we removed a resource list in order to recreate it with the same name Removing appeared to be successful When trying to recreate it we got a message it already existed We were forced to use another name Undeploying an APN in version 2 1 gives the following message 10 Undeploy Custom APN Workflow Currently the Active Endpoints BPEL Engine does not support remote undeployment so to manually undeploy the Custom APN Workflow go to the machine with the IP 127 0 0 1 and open the folder Yo CATALINA HOME bpr There delete the file CustomAPNWofklow uclpv2_10_apn bpr Then open the work Folder and delete the folder ae_temp_CustomAPNwWorkflow uclpv2_10_apn_bpr Figure 5 Undeploying an APN e The color property of links in the logical network editor cannot be changed The GUI suggests it can be done but the chosen color isn t applied This was a real problem our background image and the default color of a LP WS were the same Therefore links weren t visible e Sometimes when deploying an APN we got no target service to operate for Developers sent us a updated pre release for thi
6. services in one or more layers e An organization owns physical resources that are managed by one or more Physical Network Administrators PN Admin The PN Admin is autho rized to create use and modify all of the services within these layers Besides using the resources himself he can also lease them to others e A Virtual Network Administrator VN Admin operates at the top two layers This means he will not be able to modify the physical network Instead he is offered LP WS s and ITF WS s that he can use himself or lease to others A VN Admin is able to create APN s for himself and third parties and can add resources to a specific APN e The End User can only access the services a VN Admin offered him All users can add users of their own organization that have the same or less privileges This is done using the User Management Web Service UM WS that is build on OpenLDAP Each user must be authenticated and their user role must be known before they can access the system WS s use these credentials to validate the use of the WS by this particular user 5 Installation and Usage of UCLP 5 1 The Testbed We assembled a testbed using three Nortel OME 6500 s that were available in an existing SURFnet6 testbed The OME s are interconnected using the OC192 cards as a triangle see Figure 5 1 One of the OME s is used to connect the host on which we installed UCLP system We have been using UCLP version 2 the Ottawa impleme
7. User Controlled Light Paths Carol Meertens Tijmen van den Brink February 2 2007 Contents 1 2 Introduction Objectives Design Principles 3 1 Service Oriented Architecture o 3 2 Resource Management e 3 3 Virtualization layer e a s so ss a at 3 4 Higher Level Services and Applications ee Security dl Userroles te aa eee o B AAA Ta nd bi Installation and Usage of UCLP Del The Testbed we ama eee heed hee oe re eat AY 5 2 Creating a Lightpath o Did ISSUES ii de toas Me A A NAAA A er UCLP and DRAC Gils DRAC ir e oe Get Be a e balada 6 25 similarities ex 2 a aan A A A e da A 6 3 Difterences ee Summary and Future work Acknowledgements Appendix Installing UCLPv2 0 on Debian GNU Linux List of Figures UCLPv2 Service Oriented Architecture 1 UGEP testbed tema a annet ae see ar oane a a Se eee Lightpath in a scenario 2 ee ee Undeploying an APN eeen TE WN EE List of Tables 1 Differences between DRAC and UCLP aaa Physical Network Editor letting UCLP know about NE s and links 11 12 12 12 13 15 Abstract UCLP is a service oriented system offering the user process the abil ity to set up and tear down lightpaths at will A testbed was configured using three Nortel OME6500 SDH switches and a UCLP installation ver sion 2 of the Ottawa implementation W
8. arize the software so they could also reuse their code SOA adds the possibility to remotely use services offered by systems using their own technology A SOA is an architecture in which resources e g network elements inter faces lightpaths are being exposed as services Such a service s interface must be platform independent and should be dynamically discoverable Another re quirement is that it should be possible to remotely invoke this service In a lot of cases these services are web services because of the protocols used HTTP XML UDDI WSDL and SOAP By offering these seperately accessed services that could be part of a larger application a few problems are eliminated First of all a service can be reused by several applications Secondly they use the same instance of the service and thus a bug in one service will cause only that service to be fixed as opposed to fixing a bug in a module that has been used in the code of several different applications UCLP s SOA is depicted in Figure 3 1 The lower layer exposes web services that manage and control network elements For the Higher Level Services or Applications to control the network elements the second layer provides an ab stract interface This way the underlying technology is of no importance for the Higher Level Services or Applications which makes integration into applications less complex and more robust The next subsections subsection 3 2 3 3 and 3 4 will discuss these la
9. ation of version 2 1 Version 2 0 seemed to hang if there were zero cross connects in one of the OME s e In Version 2 0 A Java nullpointer exception was thrown when running an APN After a lot of searching we discovered this should be related to the fact that UCLP does not support VCAT This isn t documented very clearly and the error message didn t help very much to find the problem Error messages in version 2 1 appear to be more elaborate 5Virtual conCATenation testbed zen e hi Pd M r a Bs a he B C testbed testbed APN scenario_0 scenario_1 Figure 4 Lightpath in a scenario Sometimes in both versions when trying to create a connection one gets the error message TTL less than required usage time After cleaning up the database and start over defining WS s and APNs a connection can be created without this message We did not find out what caused this UCLP does not set a name in the Nortels for the cross connects it creates in Nortel s Site Manager the cross connect s name column is empty For interational reasons it would be nice to have some indication that the cross connect was created by UCLP an organization or user name or the endpoints of the associated lightpath Creating a physical network in version 2 0 involved a lot of pointing click ing and repetitive work The introduction of profiles in version 2 1 greatly improves on this Scheduling is not yet implemented
10. e investigated the design and development status of UCLP and compared it to DRAC UCLP is built upon existing and open SOAP technology In its design the concept of network is being kept very generic so the UCLP system will well be able to adopt to future insights The implementation investigated isn t production ready 1 Introduction This is the report of our one month internship at SARA We have been installing an implementation of User Controlled LightPaths UCLP We assembled a working UCLP testbed and evaluated the UCLP system Today creating connections in the field of optical networks can be quite a burden and costly There is a lot of administrative labour associated with creating a lightpath And once that is done there often isn t a 100 guarantee the lightpath will be there at the right time In some environments this is not acceptable Think about grid and optical network research there is a real need for lightpaths both dynamically configurable and reliable UCLP is an attempt to offer the user a way to setup and tear down light paths without any of the above mentioned the administrative burden and risc The design of UCLP is based on the broad concept of Service Orientation Ar chitecture Among other things this means the user does not need to be a human being interacting through a GUI The user can and will very often be an application for example a distributed system interfacing with UCLP thro
11. eases robustness To orchestrate interactions between ITF WS s and LP WS s an XML based language is used called Business Process Execution Language BPEL Using BPEL workflows can be created like the LP WS which is the orchestration of two web services that both control a network enabled endpoint Note that these workflows can be modified to add more functionality for instance by invoking another web service 3 4 Higher Level Services and Applications The previous subsection discussed the abstracted interfaces the LP WS and ITF WS provide Services and applications that reside on the top layer are now able to manipulate the underlying physical network without having to know what technologies are used This great advantage can be used to build new services e g VPN services reservation services bandwith on demand on top of the existing services At the moment only one higher level service has been actually implemented The Articulated Private Network APN service allows users or applications to combine the provided resources LP WS s and ITF WS s and create their own virtual network Such a virtual network is called an APN scenario One or more of these scenarios can be deployed to the UCLPv2 backend After the scenarios are deployed one particular scenario can be set by an application or user and the underlying hardware will be configured accordingly The following operations are offered by the APN WS 1 e Init userID I
12. edback on our pre presentation Last but not least we thank SARA who gave us the opportunity to do this project References 1 Albert Lopez Sergi Figuerola Michel Savoie Eduard Grasa Joaquim Recio Uclpv2 A network virtualization framework built on web services 2007 2 Greg Meredith Sanjiva Weerawarana Erik Christensen Francisco Curbera Web services description language 2001 Online accessed 27 January 2007 6 Thanks to the UCLP developers of i2CAT who actually planned to release the software in the first half of 2007 we were able to test this new release 13 3 M Nottingham M Baker Simple object access protocol 2004 Online accessed 27 January 2007 14 9 Appendix Installing UCLPv2 0 on Debian GNU Linux This is a log of a successfull installation of UCLPv2 0 on Debian I m starting out with a clean Debian Sarge installation This page is to be used alongside the installation instructions found at http www uclp ca uclpv2 documents help uclpv2 0 2 d d 9 jan 2007 10 jan 2007 cmeertens os3 nl Install Java downloaded jdk 1_5_0_10 linux i586 bin from http java sun com javase downloads index jdk5 jspl click Get the JDK download somewhere at the top of the page this is the linux self extracting file non RPM d d 9 jan 2007 The jre would have been sufficient I recommend the latter as it is smaller installed it as a normal user from within home uclp install workdir got an hellow
13. end make make test make install Did not copy slapd conf from uclp instead edited slapd conf from install Command slapadd gave an error on format of email in init ldiff but it did create database entries so 1 decided to continue The decision to not copy slapd conf was an error You SHOULD copy it libexec slapd d 1 h ldap 127 0 0 1 9009 GUI Installed WinXP pro and downloaded the GUI and its patch Installed the GUI Not the patch not planning to use testmode Installed JRE Login didn t succeed admin not in LDAP DB Created a separate ad min 1dif Login didn t succeed passwd is ok was thrown back to login screen Wrong LDAP version no see below Created uclpv2 ini Connect succeeded Adding a user gives bad attribute type Reconfiguring LDAP using uclp s slapd conf makes it work 17
14. ers e LR WS Manages logical routers Some routers are able to partition a single router into multiple logical devices that perform independent rout ing tasks each logical instance has its own routing table and protocols These logical devices are called logical routers MPLS WS Allows UCLP to control MultiProtocol Label Switching MPLS based devices INS WS Presents a simple interface to control instruments such as sen sors data sinks sources and storage devices GMPLS WS Allows UCLPv2 to trigger switched Generalized MPLS GMPLS connections using the O UNI Optical User to Network Inter face To implement services the Web Service Description Language WSDL is used It s an XML based language that describes services with it s functions 2 In case of the XC WS two port types are created One to manage the network element XC ConfigPort and one to manage the resources XC Operational Port Relatively they contain functions to create modify and delete network elements and to use release bond partition un allocate query subLease and return resources In order to remotely use these functions XML based messages are sent invok ing a particular function The protocol used to send XML based messages over HTTP is the Simple Object Access Protocol SOAP 3 The UCLP backend uses Apache Axis as it s SOAP Engine A client can connect to a web service and query or invoke the available functions that are listed in a WSDL
15. file At the moment the configuration of the physical devices relies on TL1 In the future Command Line Interface CLI and NetConf will be added To establish the connections between the NE WS and the physical devices UCLPv2 supports TCP UDP and SSL 3 3 Virtualization layer As stated in subsection 3 1 the Resource Virtualization Services layer provides an virtualized interface to the Higher Level Services or Applications in order to control the network elements At this moment there are two types of services being e Lightpath Web Services e Interface Web Services To provide a standard interface to the top layer some virtualization of the cre ation of a lightpath that is technology dependent has to be made This is done by the Lighpath Web Service LP WS Just as the XC WS this service provides operations to manipulate the layer below it These operations are 1 e Create Creates a new instance of a LP WS e Delete Destroys the LP WS instance If it has a finite lifetime the LP WS instance will destroy itself upon lifetime expiration e Query Provides data about the LP WS properties bandwidth endpoints expiration date etc and status in use available faulted e Use Causes the LP WS to call the NE WS which in turn will configure the network element in a certain way depending on the network element technology create a cross connection create a VLAN or create an LSP Release Reverts the use operation cause
16. nitializes the APN a new process is created in the BPEL engine Some validation actions are performed to ensure the correctness of the device configurations e SetConfig scenarioID userID usageTime Performs all the device con figurations specified in the scenario named scenarioID Checks that the user userID has the valid access rights to set up the scenario When the usageTime is over the scenario is automatically unset e UnsetConfig scenarioID userID Clears all the device configurations spec ified in the scenario name scenarioID Checks that the user userID has the valid access rights to teardown the APN e QueryStatus userID Returns the status of the APN i e provides infor mation about the scenario being executed e Stop userID Destroys the process instance of the APN in the BPEL engine 4 Security This section covers how security is imlemented by using user roles in the UCLPv2 architecture Besides these user roles as UCLPv2 is still under development there are quite some security issues that need to be solved e g storing pass words in clear text datacommunication over an unsecured protocol This re port does no security audit on UCLPv2 but will discuss the security as it is implemented at this moment 4 1 User roles The UCLPv2 security architecture relies on user roles This architecture can be explained by the layered model depicted in Figure 3 1 where the three different users can access and or modify
17. ntation SLDAP stands for Lightweight Directory Access Protocol and is used to modify or query directory services 4Communications Research Centre Canada CRC University of Ottawa i2CAT Foun dation and Inocybe Technologies The software and documentation is downloaded from http uclp ca En host host Figure 2 UCLP testbed 5 2 Creating a Lightpath To give an impression of the look and feel of the UCLP GUI we will describe shortly how a lightpath in UCLP is created For more detail the user manual that comes with UCLP is a good source of information When starting the GUI one first needs to log in After logging in the user adds the information about his network network elements and links to UCLP He does that by using the Physical Network Editor see Figure 5 2 When adding a network element to the Physical Network Editor one gets the oppor tunity to enter the required credentials i e a login for a TL1 interface and or the path to an SSL certificate Each link and each network element interface can be used to create a re source web service Resources are assembled in a resource list and can be added to or removed from an APN Articulated Private Network For each APN multiple scenario s can be created Figure 5 2 shows a scenario resembling a lightpath The user activates one scenario at the time On activation of a scenario the UCLP back end system configures the network elements In our testbed that
18. orld working export JAVA HOME home uclp install_workdir jdk1 5 0_10 Install Apache Tomcat downloaded http apache proserve nl tomcat tomcat 5 v5 5 20 bin apache tomcat 5 5 20 tar gz and unpacked it export CATALINA HOME home uclp install_workdir apache tomcat 5 5 20 Install Apache Axis There is axis C and axis Java took Java http archive apache org dist ws axis 1 3 axis bin 1_3 tar gz Install Axis in Tomcat cp Rp axis 1_3 webapps axis apache tomcat 5 5 20 webapps needed activation jar Install the UCLPv2 Web Services downloaded http www uclp ca files uclpv2 uclpv2 0 2 WS_2006_08_08 zip install to home uclp install workdir UCLP it doesn t ask for start menu items Create KeyStore for NE WS did not perform this step 15 BPEL Engine downloaded http www activebpel org download files 2 0 final activebpel 2 0 bin zip ran install sh Install MySQL downloaded static linux mysql 4 1 via http dev mysql com downloads mysql 4 1 html and unpacked following INSTALL BINARY scripts mysql_install_db user uclp configured a mysql root password Create the database for the Active Endpoints 2 0 BPEL engine mysql u root p lt ActiveBPEL MySQL sql Setup a Tomcat datasource downloaded http apache essentkabel com tomcat tomcat 5 v5 5 20 bin apache tomcat 5 5 20 admin tar gz tomcat startup sh does not need explicit backgrounding mysql_safe does Login using
19. rk topology towards endusers Table 1 summarizes some important differences between UCLP and DRAC DRAC UCLP Provides short lived lightpaths long term APNs Pathfinding by algorithm by user process Scheduling both start end end date end date planned Bandwidth usage optimising fixed VCAT support yes no Strength scheduling scenario s abstraction Delegation of resources no yes Client browser windows executable Licence proprietary GPL Table 1 Differences between DRAC and UCLP 7 Summary and Future work User Controlled Lightpath is a concept that arose to fulfill the need to dynam ically create lightpaths The creation of these lightpaths is done by users or applications It is based on a service oriented architecture that enables the abstracted physical resources to be exposed as web services Users and appli cations can use these web services to create their own dedicated network without the knowledge of the underlying technology 12 Securing UCLPv2 is done primarily by the authentication and authorization of users Improvements will have to be made to provide a safe UCLP environ ment Installing UCLPv2 on both Linux and Windows was without problems However we did encounter some problems using UCLPv2 0 Most of these prob lems were fixed in the pre release of UCLPv2 1 Using the UCLP software with the SURFnet6 testbed turned out to be quite easy The only problem encountered was a card that initially was not
20. s but that didn t solve the problem The pre release of version 2 1 seems to be more stable then version 2 0 Also the GUI shows some important improvements i e e version 2 1 shows existing cross connects in white e version 2 1 adds the concept of scenario s to define different APN setups e version 2 1 seems to be working faster i e when creating ITF WS s in PN editor UCLP is built upon open technology Tomcat Axis JSP At the time of this writing source code and API for version 2 aren t available UCLP is ex pected to be well extensible once the technical documentation is online Version 2 1 and the accompanying technical documentation will be released in the first half 2007 6 UCLP and DRAC 6 1 DRAC Like UCLP DRAC Dynamic Resource Allocation Control is a service oriented system built using Java and JSP End users using DRAC create their lightpath by selecting its two endpoints i e by selecting two gigabit ethernet ports as endpoints for a connection Requesting a lightpath is done by scheduling it using a web client or web services The user always uses a start time and an end time when scheduling a lightpath If the schedule is successful DRAC will establish the lightpath during the given time interval The user explicitly needs to be authorized for the lightpath s endpoints DRAC internally decides on the route between the endpoints This decision is based on the values of a few optimization parameters
21. s the LP WS to call the network element web services which in turn clean the network element configura tions Partition If it is physically possible the LP WS is divided in N LP WSs with smaller bandwidth The addition of all the bandwidths must match the original LP WS bandwidth e Bond If it is physically possible a group of LP WS with the same net work endpoints is combined into a single LP WS whose bandwidth is the addition of all the original LP WSs bandwidth e Lease Changes the ownership of the LP WS The same applies to the interface of a network element An interface is a single port on a network element and to provide it s services to the top layer in a standardized manner an abstraction is made This abstraction called an Interface Web Service ITF WS causes the underlying technology to be 2NetConf is a protocol to configure network elements hidden from the top layer just like the LP WS The operations provided by this service are the same as the ones of the LP WS except the partition and bond operations which do not apply to an interface These two services are the building blocks of the system They can be used by users to create their own virtualized network but also by applications that can interface with these services The biggest advantage in this layered and abstracted approach is that technology at the lower level is hidden from the top level which allows for easy integration into applications and it incr
22. ugh UCLP s API It will be able to setup and tear down lightpaths at will 2 Objectives The primary objective of this project was to build a testbed consisting of some optical hardware and the UCLP system SARA was interested in the design and in the development status of UCLP Three Nortel OME 6500 s were available in an existing SURFnet testbed Other objectives were to compare its functionality with DRAC s and to evaluate interoperability aspects between the two Some examples of interesting questions to answer e Is it difficult install UCLP what is the quality of the software e What are the UCLP design choices made e What kind of user roles are defined How does an end user create a lightpath e How does UCLP handle scheduling 3 Design Principles This section covers the design principles of UCLPv2 First the concept of a Service Oriented Architecture is explained followed by the explanation of each layer as shown in Figure 3 1 3 1 Service Oriented Architecture The Service Oriented Architecture SOA is relatively new in the IT world However the foundations of SOA date from ten years ago To understand the design principles of UCLP it s important to understand the concept of a SOA and why it s so usefull This will be explained in this section The evolution of programming shows us that in the beginning monolithic software was written This soon led to software getting too complex The next step was to modul
23. yers in more detail 3 2 Resource Management As stated earlier in this document the lower layer exposes web services called Network Element Web Services NE WS that control the resources of physical network elements The way these devices are managed depends on the technol ogy they use As of today only one technology has been implemented by the developers of UCLPv2 as NE WS which is the Cross Connect WS XC WS This WS controls physical devices and is able to create and delete Cross Con nections As depicted in Figure 3 1 a lot more technologies are possible and could be implemented A few of these technologies are 1 New implementations as the MPLS WS and an Ethernet WS are known to be imple mented by HEAnet which is Ireland s National Education amp Research network at tek Higher Level APN WS y CARS Services Applications Any other service GUI clients Resource LP WS ITF US geste Virtualization Services Resource ext E WS esos Es INS E as Management Services a E S a j Figure 1 UCLPv2 Service Oriented Architecture 1 e XC WS Manages devices that are able to create Cross Connects on SONET SDH based equipment wavelength switching based equipment and fibre cross connects Currently the XC WS is the only member of the NE WS family that has been implemented 802 1q WS Manages devices that use Virtual Local Area Network VLAN technology to multiplex connections belonging to different us
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