im trying to set up Asterisk as a T.38 Gateway and im running into Issues regarding signaling of call completion to a T.38 endpoint.
The problem seems to be caused by Asterisk, upon receiving a BYE from the other endpoint, trying to cancel the T.38 Session by sending a udptl port 0 ReInvite before sending a BYE, which the T.38 endpoint does not understand, eventually causing a timeout on the side of the endpoint before the BYE is finally sent from asterisk.
Is there any way to force asterisk to “skip” sending these reinvites and completing the call with a BYE immediately?
That looks like a real 408, not a virtual one, meaning the remote end did understand the request. I don’t think an ACK would be sent to a virtual timeout.
The 408 is a response from the T.38 endpoint to the port 0 ReINVITEs, this exact call flow (reinvite with 2 retries leading into the 408) is reproducable.
Somewhere after the 408 and before the BYE the T.38 endpoint seems to have terminated the dialog, leading to the 481 response to the BYE.
(The “missing” BYE seems to cause the fax software of the endpoint to assume that the fax sending process was unsuccessful, leading to unnecessary retries)
