[SR-Users] Handling 422 Message (was: Re: dlg_vars of existing dialog not set after loose_route())

Hi

After more intensive testing, I narrowed the issue down.

CPE A => Kamailio+dialog => CPE B

CPE A is sending an INVITE with a session timer too smal for CPE B.

CPE B replies with 422.

This causes the dialog module to trigger the 'call failed' event and attempt to delete the dialog data.

CPA A does not consider the call failed. It repeats the INVITE with CSEQ + 1 and with the session timer as desired by CPE B.

The call is then processed as if in dialog, but some, strangely not all, dialog variables are lost.

I fear the repeated invite with identical callID and from_tag causes a race condition in handling the dialog variables.

I see there are two attempts by the dialog module to write a CDR with the same callID. After processing the 422 and when the call ends while processing BYE.