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Troubleshooting voice QoS in OCS 2007 R2 RRS feed

  • Question

  • We have built a consolidated OCS 2007 R2 enterprise pool with approximately 50 pilot users.

    What we are seeing (or rather hearing) is quite consistent poor VoIP audio quality in both direct client-to-client calls and conference calls (only Office Communicators or Live Meeting being used as clients in the current OCS pilot).

    Occasionally, the voice is crystal clear but more than often the sound turns pretty much into gibberish and in extreme cases the calls get disconnected after a couple of seconds sometimes crashing the Communicator. Some users also see Communicator warning about poor network quality.

    The server has 1 GB network interface, most users are in 100 MB LAN (although some come through VPN). Using basic monitoring tools available on the Front End server, we've not seen significant CPU, memory, disk or network usages during the calls that have problems.

    Do you have any suggestions on how to start troubleshooting/fixing the issue? In particular:

    - How could we get hard facts the problem is in the network and not in something else?
    - How could we isolate the problem (i.e. where in the network do we have problems)?
    - What steps would we have to identify the corrective measures needed?

    I've shortly investigated QoE Monitoring Server which would seem to have features that could help in our case but I'm afraid we won't be able to deploy it into the environment at this point. We've also made our first attempts on analyzing the issue with Wireshark but there are still some issues with that we need to resolve (namely doesn't seem to be able to analyze SIP over TLS and for some reason the RTP traffic wasn't automatically detected as RTP either).

    All ideas, tools and resources are very much welcome!
    Thursday, February 5, 2009 7:48 AM

Answers

  • You will get most information from the QoE monitoring server
    But you can also troubleshoot audio with the Deployment Validation Tool
    http://blogs.msdn.com/byrons/archive/2008/03/19/deployment-validation-tool-part-1-of-2.aspx
    - Belgian Exchange Community : http://www.pro-exchange.be -
    Monday, March 9, 2009 11:23 PM
  • Keijo,

    In order to analyze the traffic you'd need to export the private key of the Front-End certificate, which most likely was not included in the original setup.  So you can either request a new certificate and mark the checkbox to include the private key in the wizard and then use that certifacte with Wireshark to decrypt the traffic, or you can enable your FE server to listen on TCP and configure a test client to use TCP only and then trace that traffic.
    Jeff Schertz, PointBridge | MVP | MCITP: Enterprise Messaging | MCTS: OCS
    Tuesday, March 10, 2009 1:06 PM
    Moderator

All replies

  • You will get most information from the QoE monitoring server
    But you can also troubleshoot audio with the Deployment Validation Tool
    http://blogs.msdn.com/byrons/archive/2008/03/19/deployment-validation-tool-part-1-of-2.aspx
    - Belgian Exchange Community : http://www.pro-exchange.be -
    Monday, March 9, 2009 11:23 PM
  • Keijo,

    In order to analyze the traffic you'd need to export the private key of the Front-End certificate, which most likely was not included in the original setup.  So you can either request a new certificate and mark the checkbox to include the private key in the wizard and then use that certifacte with Wireshark to decrypt the traffic, or you can enable your FE server to listen on TCP and configure a test client to use TCP only and then trace that traffic.
    Jeff Schertz, PointBridge | MVP | MCITP: Enterprise Messaging | MCTS: OCS
    Tuesday, March 10, 2009 1:06 PM
    Moderator
  • Thanks for the answers. Partly due to enterprise voice deployments we also installed the QoE monitoring server and have been able to enjoy from mostly super crisp voice quality :)

    Most of the problems we experienced have been due to supbar headsets that include too much background noice. With OCS optimized headets and/or otherwise higher quality devices the sound quality has been remarkably better.

    MCTS: OCS
    Tuesday, June 16, 2009 6:31 PM