no you
don't. ser can quite easily be made to turn the 302 to an
another invite, where b is listed as caller in rpid or diversion
header.
How do you turn 302 to an INVITE in ser?
I made simple function to avp.c with a new function called contact2attr and
put it in the reply_route. Then in failure route just using attr2uri,
append_branch, and relaying the new invite again (ofcourse adding diversion
header first so guy would be billed).
Jens Davidsen