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Cisco TelePresence MCU 4200 Series

How do I produce a network trace of the traffic between my Cisco TelePresence MCU and another piece of equipment?

How do I produce a network trace of the traffic between my Cisco TelePresence MCU and another piece of equipment?

This article applies to the following products:

  • Cisco TelePresence MCU 4200 Series
  • Cisco TelePresence MCU 4500 Series
  • Cisco TelePresence MCU 5300 Series
  • Cisco TelePresence MCU MSE Series
  • Cisco TelePresence Advanced Media Gateway 3600

A network trace is a capture of raw network traffic as it appears 'on the wire'. A trace showing the traffic between the Cisco TelePresence MCU and an endpoint, gateway or gatekeeper is often an essential part of solving problems. This article explains all the steps required to obtain a network trace, using Wireshark, which your support representatives may request when they troubleshoot your problem.

Prerequisites

  • A PC, running Windows 2000 or newer, with Wireshark installed. Wireshark is available from www.wireshark.org/download.html *
  • A 10/100 Mbps (or better) network hub, or a switch with port mirroring enabled.
  • A hub allows each port to see the traffic to and from every other port, allowing the PC to trace traffic between the MCU and the endpoint, irrespective of which hub port the MCU/endpoint uses. Port mirroring is required if you want to use a switch instead; with port mirroring enabled, traffic on the MCU/endpoint switch port is copied to the PC switch port, thus enabling the trace.

  • Patch cables to connect the PC and MCU or endpoint to the hub/switch, and to connect the hub/switch into the rest of the network.

*Cisco TelePresence is not responsible for the content of third party web sites.

Capturing the trace using a network hub:

  1. Connect the hub into the network.
  2. Connect the PC into the hub.
  3. Connect the endpoint into the hub.

    Now the PC's network interface will be able to see all the traffic that passes between the MCU and the endpoint.

  4. Start Wireshark.
  5. Go to Capture > Options.
  6. In the Capture Filter field, enter:

    host aaa.bbb.ccc.ddd where aaa.bbb.ccc.ddd is the IP address of either the MCU or the endpoint. To capture only relevant traffic, it is best to enter the IP address of the host which is not connected directly to the hub with the PC. Therefore, if you have the MCU plugged into the hub, enter the IP address of the endpoint into the capture filter. Alternatively, if you have the endpoint plugged into the hub, enter the IP address of the MCU into the capture filter.

  7. Select the correct network interface from the pane listing possible capture interfaces.
  8. Click OK.

    Wireshark starts tracing. It will capture all traffic whose source or destination IP address is the host address you entered in the capture filter.

  9. While the trace is running, attempt to reproduce the problem between the MCU and the endpoint.
  10. Click Stop on Wireshark's capture window after you have reproduced the problem.
  11. Save the captured packets in Wireshark's native .pcap format and send the file to your customer support contact.

Capturing the trace using a network switch:

  1. Connect the PC and MCU into the switch.

    Your MCU will probably already be connected to an appropriate switch; if you have access and are authorized to configure the switch, connect the PC into that switch.

  2. Configure the switch to mirror all traffic to/from the MCU's switch port across to the PC's switch port.

    Sample instructions can be found at https://supportforums.cisco.com/docs/DOC-2632.

    Now the PC's network interface will be able to see all the traffic that passes between the MCU and the endpoint.

  3. Start Wireshark.
  4. Go to Capture > Options.
  5. In the Capture Filter field, enter:

    host aaa.bbb.ccc.ddd where aaa.bbb.ccc.ddd is the IP address of either the MCU or the endpoint. To capture only relevant traffic, it is best to enter the IP address of the host which is not connected directly to the switch. Therefore, if you have the MCU plugged into the switch, enter the IP address of the endpoint into the capture filter. Alternatively, if if you have the endpoint plugged into the switch, enter the IP address of the MCU into the capture filter.

  6. Select the correct network interface from the pane listing possible capture interfaces.
  7. Click OK.

    Wireshark starts tracing. It will capture all traffic whose source or destination IP address is the host address you entered in the capture filter.

  8. While the trace is running, attempt to reproduce the problem between the MCU and the endpoint.
  9. Click Stop on Wireshark's capture window after you have reproduced the problem.
  10. Save the captured packets in Wireshark's native .pcap format and send the file to your customer support contact.
  11. Configure the switch to end port mirroring.

February 13th, 2013 TAA_KB_139