20 Apr
2021
20 Apr
'21
7:03 a.m.
Sorry, but it turned out that in calls where B replies first with "183 Session Progress" and which A acknowledges with PRACK request, P1 is not able to forward the PRACK, but responds with "404 Not found".
I cannot reproduce this in my test environment, because I don't have a SIP UA that uses Session Progress. Here is censored debug from production environment on what happens when P1 receives the PRACK:
https://box.tutpro.com/tmp/prack.debug
-- Juha