Eventid 25073 Enable comfort noise on your trunk (Audiocodes)

2018-01-11 1 min read Skype for Business Erwin Bierens

Hi All,

First blog of the year, officially not allowed anymore but best wishes for all of you!

After going through some event logs on Frontend servers i came across this warning:

The Mediation Server service has received a call that does not support comfort noise from the Trunk, SBC01.domain.com;trunk=SBC01.domain.com Cause: The Trunk does not support comfort noise. Resolution: Please ensure the comfort noise option on the Trunk has been enabled.

For the ones who are not familiar with the term, Comfort noise (or sometimes called comfort tone) is synthetic background noise used in communications to fill the artificial silence in a transmission resulting from voice activity detection or from the audio clarity of modern digital lines. If want to read more about Comfort Noise i suggest you to the following pages Wikipedia, and RFC3389.

I’m running a Audiocodes Mediant 1000 for this customer, so let’s fix this warning.

RFC 3389 CN Payload Type
Comfort Noise Generation Negotiation

Then go to Setup, Signaling&Media, Coders & Profiles, Coder Groups

Enable the Silence Suspression for all of your configured coders.

That’s All!