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Network Issues from the Mediation Server to the PSTN

Microsoft Office Communications Server 2007 and Microsoft Office Communications Server 2007 R2 will reach end of support on January 9, 2018. To stay supported, you will need to upgrade. For more information, see Resources to help you upgrade your Office 2007 servers and clients.

You can troubleshoot network issues from the Mediation Server to the public switched telephone network (PSTN) as follows:

  1. Check the event log of the Mediation Server for error messages related to connectivity or network problems. For details about relevant Office Communications Server events, see Appendix A: Enterprise Voice-Related Events.

  2. Ping the IP address of the PSTN gateway from the Mediation Server to verify the network connectivity to the gateway.

  3. Start Performance Monitor, and then add the Mediation Server – Outbound Calls object so that you can view the counter values for the Mediation Server. For details about relevant Office Communications Server performance counters, see Appendix B: Enterprise Voice-Related Performance Counters. For details about using Performance Monitor, see Perfmon on Microsoft TechNet at https://go.microsoft.com/fwlink/?LinkId=143009.

  4. Record the current Mediation Server counter values. You will use changes to these values to make decisions in the steps that follow.

  5. Attempt a new outbound call to a PSTN number from an Office Communicator client.

  6. Look at the following Mediation Server current counter values:

    • Calls Attempted. If the Calls Attempted counter has not changed, the call did not reach the Mediation Server. If the Calls Attempted counter has incremented, the call reached the Mediation Server.

    • Invites Forwarded to Gateway. If the Invites Forwarded to Gateway counter has not changed, the Mediation Server could not process the incoming call attempt from Office Communicator (that is, through the Office Communications Server by proxy). Enable Windows preprocessing (WPP) tracing on the Mediation Server for session logging, and then reattempt the call. If the call fails again, look at the trace output for information about why the Mediation Server could not process the call. For details about WPP, see WPP Software Tracing on Microsoft MSDN at https://go.microsoft.com/fwlink/?LinkId=145787.

      If the Invites Forwarded to Gateway counter was incremented, check the Calls Established counter. If the Calls Established counter is not incremented, check the configuration and connectivity of the PSTN gateway.

    • Calls Established. If the Calls Established counter was incremented, and the two parties could not talk, there is an issue with audio. Check the endpoint device, ensure that the PSTN Gateway has been configured for the correct G.711 variant for the locality where it is installed, that the Mediation Server to MRAS handshake is successful, and that you can successfully use the Media Relay when the client and the Mediation Server are separated by network address translations (NATs).

  7. Check the gateway logs to ensure that the PSTN gateway received the call and was able to process it.