You’ve configured Skype for Business integration with Polycom RealPresence Collaboration Server 1800 to allow Skype for Business clients to join into scheduled Polycom meetings but notice that an attempt to dial into the meeting would ring but the Polycom does not answer. Performing a logging session reveals the following entries:
SIP/2.0 500 Server Internal Error
Previous hop server component did not report diagnostic information";Domain=”internalPolycomDomain.com”;PeerServer=”yourPolycomDMAserver.com”;source=”yourSfBFEserver.com”
I encountered this error after several components of the Polycom conferencing server were moved from one datacenter to another and the error messages provided by the trace did not help because it did not point me to the right direction. What did was logging into the RMX Manager and reviewing the Signaling Monitor status, which revealed the following:
Relay Server UDP Not Available
Relay Server TCP Not Available
What ended up causing this issue was that the relocated RMX server was no longer able to reach the Skype for Business Edge Server (not the front-end server) and reconfiguring the firewall to allow the required ports corrected the issue.