Sebastian Damm writes:
In serial forking, the new INVITE could go out before
the CANCEL is
sent out. If that happens, the Via branch is needed to not kill the
whole call.
There would not be a CANCEL when a serial branch returns negative
response. In the case where waiting for final response from a branch
times out, there would be cancel, but also a proxy generated negative
response. I would think that in both cases it is safe to delete the
whole call in failure route and then make a new rtpengine-offer.
-- Juha