We are seeing a lot of the following Event Viewer warnings on our Lync Server 2010 Mediation Servers:
The Mediation Server service has received a call that does not support comfort noise. This event is throttled after 5 calls from a single Gateway peer.
The Mediation Server service has received a call that does not support comfort noise from the Gateway peer, dmg2xxx.contoso.com
Cause: The Gateway peer does not support comfort noise.
Please ensure the comfort noise option on the Gateway has been enabled.
Where would this be configured on the DMG2xxx (Version 6.0 Service Update 7.0)?
DMG web interface --> VoIP --> Media --> Voice Activity Detection (ON by default)
Hope this helps