I do have an unexpected problem with some external connections. Only a few calling parties are involved, but I can reproduce the problem to 100% with them.
Immediately after one picks up the receiver to answer the call, Asterisk terminates the ongoing call:
I am using Asterisk 16.5.0 with the pjsip stack and the Asterisk box in the SIP flow diagram has the 80… IP. The external trunk is the German Telekom SIP-Trunk. I’d like to point out again that only a few calls are affected here, so something from the outside seems to trigger this odd behavior.
At first glance, I don’t see a 183, but a 491 and it looks as if there is a superfluous re-Invite or the other side cannot answer the re-Invite properly.
What can I do?