Dropped SIP Call after 10 Minutes

[Curtis Trudeau]

When we place an outbound call to a specific phone number the call will drop after 10 minutes.  The number is a goto meeting conference hosted by another company.  There are around 20 people on the conference and we are the only ones dropping.  We have not experienced this when calling any other numbers.  Issue is present when calling from various phones at the same location.  ATT SIP trunk is a recent change and the issue started after we began using it for outbound calls. 

Phone--->CUCM 11.5 (SCCP or SIP)--->4331 15.5(3)S6b (SIP)--->ATT(SIP)

CCSIP Messages debug between the 4331 and ATT is attached.  It looks like we simply receive a BYE before the next invite to keep the call alive comes.  Typically we see the re-invites after 15 minutes on outbound calls.

Can anyone point me in the direction of what to look at next?

[Jonathan Schulenberg · Accepted solution]

The call is reINVITEd twice but the only change I noticed is changing who has to refresh. The final state is UAC, which for this call leg would be CUBE.

Session-Expires:  1800;refresher=uac

A refresh isn’t required for 30 minutes though. Open a ticket with ATT on this. Either they are passing it through from the far end and you have to call the conference provider for troubleshooting or ATT is generating it and needs to explain why. 

[Curtis Trudeau]

Thank you for the information!