Did you already had seen an error about comfort noise?
I have an AudioCodes Mediant 800 as a voice gateway. I came across with the following error:
So, lets do the following steps:
Go to AudioCodes, and check the Enable RFC 3389 CN Payload Type is enabled;
Also check Comfort Noise Generation Negotiation is enabled;
Then, check if the Silence Suppression is enabled;
After this, you shoudn’t have errors.