There was no response from a gateway to an OPTIONS request sent by the Mediation Server. The Gateway peer, %1, is not responding ...

There was no response from a gateway to an OPTIONS request sent by the Mediation Server.

The Gateway peer, %1, is not responding to an OPTIONS request sent by the Mediation Server service
Cause: The Mediation Server service cannot communicate with the Gateway Peer Service over SIP due to network connectivity issues.
Resolution:
Please ensure network connectivity and availability of the Gateway Peer for the Mediation Server service to be able to function correctly.