FVC accessNGI ATM switch.

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fvcswitch.jpg The FVC accessNGI (NextGenerationInternet) atm switch is manufactured by First Virtual Communications (www.fvc.com). It is intended as an access level switch and interfaces with 2mb/s leased lines, 25MB/s workstations and 155MB/s servers. It supports both SVC's and PVC's. The basic switch has an ethernet port on the control module next to the RJ45 console connection. This is not the same pinout as Cisco use. The ethernet port interfaces to the atm network using Lan Emulation. An alternative module can supply 6 ethernet ports. The built in ethernet port uses LAN Emulation to bridge to atm, but seems unable to terminate an rfc1483 pvc. We used to use them an access switches on the end of a 2MB/s G703 leased line, the ethernet port linked in to an ethernet switch, and the 25MB/s ports is used for a few pc's which need to connect to different networks. For many pc's on different networks the vether module is used to connect to a supplementary ethernet switch. The atm wan and backbone keeps the different network traffic seperate. Users page.

AccessNGI configuration.

The initial config of the switch is useless for our application, so the easiest thing is to delete it straight away. Unfortunately, unlike Cisco IOS there is no command line repeat, but the later firmware images have command completion and help at any point by typing a "?".
  • Log in as the admin user, user=admin, password=vswitch. (Just type "admin" at the prompt. This will change to "ADMIN Access_NGI>").
  • Have a look at the system ports (really for interest only) "show system ports".
  • Delete the previous config and return to factory defaults "set system delflashcfg".
  • Disable the internal Lan Emulation Configuration Server (LECS) "set lecs local disable"
  • set the atm network prefix length. "set pnni pglevel 96"
  • Set the atm network prefix and switch number (Don't use my numbers, they have to match the existing atm numbering hierachy in use). Depending on your atm network mask (pglevel in FVC speak), your ilmi netprefix may be longer or shorter than this. The .05 at the end is the switch id. "set ilmi netprefix 39.82.6f."
  • Give the switch a name for the command line prompt (This can be different from the SNMP name as they are set in different places) "set admin prompt xxxx"
This completes the basic global config. Next start to configure some interfaces:-
  • Start with module 2, port 01 (201), a 2MB/s E1 WAN port, set it to be a pnni port, use HDB3 line coding, (or see for cached version HDB3) scrambling and upstream clocking. (also this (in German) or this (in Googlified english)-(cached).
    • "set pnniport 201"
    • "set e1 line-coding 201 hdb3"
    • "set e1 scrambling 201 enable"
    • "set e1 clocking 201 external"
      Please note, the scrambling is to ensure a zero dc average level, not for encryption, security etc....
      HDB3 is "High Density Bipolar 3zero substitution", an alternative to AMI etc. This has to match the line encoding being used by the circuit provider.
      Note also that the pnni implementation includes ilmi, so do NOT enable ilmi for the port. Pnni takes care of it.
  • Next configure the ethernet port to use bridging and connect to ELAN name desired
    • "set bridge elanname elan1"
  • And configure an ip address and subnet mask on it
    • "set ip ipaddress 192.168.x.x "
    • "set ip netmask "
    • "set ip gateway 192.168.x.x"
  • 25MB/s ports, not a lot to set for workstations, for pnni to link switches together:- (note port 101 does not support pnni for an unknown reason)
    • "set sigl pnniport 106 "
After configuring some of the settings you will be prompted to reboot the switch. Just ignore these warnings until you have finished configuring everything, and perform a restart at this point ("set system reset").

Configuring the atm to ethernet bridge

The usual method of configuring the ethernet bridge is to use LAN Emulation.
  • set bridge FIXME
    • FIXME

Setting up Permanent Virtual Circuits (PVC's)

The usual method of configuring PVS's.
  • set bridge FIXME
    • FIXME

Diagnostics and monitoring

There are several commands to use for examining the current setup and traffic through the switch:-
  • Show the current setup:-
    • ADMIN switch_ID_17>show system ports
       Port      Module    IntSwitchPort    Description
       101          1             0        25 Mbps ATM
       102          1             0        25 Mbps ATM
       103          1             0        25 Mbps ATM
       104          1             0        25 Mbps ATM
       105          1             0        25 Mbps ATM
       106          1             0        25 Mbps ATM
       201          2             4        E1 ATM (IMA)
       202          2             4        E1 ATM (IMA)
       203          2             4        E1 ATM (IMA)
       204          2             4        E1 ATM (IMA)
       301          3             8        10 Base-T Ethernet
       302          3             8        10 Base-T Ethernet
       303          3             8        10 Base-T Ethernet
       304          3             8        10 Base-T Ethernet
       305          3             8        10 Base-T Ethernet
       306          3             8        10 Base-T Ethernet
       501          5            14        10 Base-T Ethernet
      ADMIN switch_ID_17>                                            
    • Show the signalling config for the system:-
      ADMIN switch_ID_17>show sigl config
      Port VPI   Version     Port Type        ILMI
      I08   0     3.0    UNI  Network Side   Enabled
      I14   0     3.0    UNI  Network Side   Enabled
      101   0     PNNI   PNNI Network Side   Disabled
      102   0     3.0    UNI  Network Side   Enabled
      103   0     3.0    UNI  Network Side   Enabled
      104   0     3.0    UNI  Network Side   Enabled
      105   0     3.0    UNI  Network Side   Enabled
      106   0     PNNI   PNNI Network Side   Disabled
      201   0     PNNI   PNNI Network Side   Disabled
      202   0     PNNI   PNNI Network Side   Disabled
      203   0     3.0    UNI  Network Side   Enabled
      204   0     3.0    UNI  Network Side   Enabled
                VP Workgroups
      Port VPI    Version     Port Type        ILMI
      ADMIN switch_ID_17> 
  • Show the traffic through the switch
    • "show scc calls" displays the current atm connections through the switch
    • Show the status of the ethernet bridge:-
      ADMIN switch_ID_17>show bridge status 
      Bridge is ENABLED
      ELAN Name in flash is ELAN1
      ELAN Name from join response is ELAN1
      FifoPkt 0 NetPkt 0. FifoBytes 0 NetBytes 0
      rej net frm 0. OFifo Blked 0 Fifo NE 0
      LEC net recvq depleted 0. HF before DB 0
      pc Trashlen 0 net Trashlen 0, misplacedDB 0, toolong 0
      isardrop 0 isaxdrop 0
      print flag 0
      ADMIN switch_ID_17> 
    • "Show atm errors" shows atm errors for all ports, "clear xxx" resets the error count.