Martin Koenig writes:
is it possible to use avp_write on the responses in failure route?
i think so.
If yes, Contact header field could be evaluated and pushed into RURI, then routing via route(x) to a new destination and finally solve the 3xx forwarding issue.
in theory yes, but when i implemented this, there was a patch to tm module that assigned final reply to sip_msg structure field called "final_reply". there is still no such field in current rel_0_9_0 sip_msg structure and i didn't see anything else either that could give access to the reply contact header.
in summary: without access to reply message, there is no way to implement this functionality.
-- juha