I have a customer that is using Bria softphones over VPN. They are getting frequent call failures with no audio.
They reported first to ATT.
I obtained this from ATT and I'm not sure how to handle it. I'm wondering if anyone has any insight as to what I can try here.
I consulted Bob XXXXXX about this issue with “m=audio field in the SIP header being set to 0.” This does not appear to be an early or delayed offer problem. It appears to refer to MiTel IP-PBX’s call treatment and routing within FTN. The comment from CounterPath “it's very likely that your SIP server is changing the 'm' line to 0” is referring to the FTN MiTel IP-PBX equipment. AT&T’s service is IPFlex only, and ATT is not changing this header field. This equipment is managed through a 3rd Party
So my first question is: Am I setting the m=audio to 0? if so, how am I doing that?
Ralph