[reSIProcate-users] How properly establish media connections?

["Mykhailo Parfeniuk" <sopyer@xxxxxxxxx>]

As far as I understand media connection should start like this:
                        INVITE
                    ----------------------> making decision about call, accepting
                          200 OK
opening         <-------------------- openning port for listenning for incoming send 200
port for
listenning 
for incoming
 media and
starting
 transfer 
media                   ACK
send ACK     --------------------> starting transfer media

For session instantiation there are callbacks in resiprocate, and if sdp is sent with first 
invite it is possible to implement such a scheme. But for re-INVITE or UPDATE
there are only 2 callbacks onOffer and onAnswer. I can't properly decide when start 
transfer media if you are the side that answer for offer. Is there in resiprocate callback
for this purpose (as I know onConnectionConfirmed is not called)? Or what are other
 schemes for implementing media transfer properly   (in synchronous way, without 
situation "destination unreachable").