2009/2/4 Padmaja R <urvthme(a)gmail.com>om>:
Say A and B are in a SIP call, and A and B suddenly
decide to have a
conference with C. A puts B on hold and dials C' s number. After call
between A and C is up, if A presses hook flash, this sends an invite to the
conference application namely: conf@openseratlocalhost:5060 (which is the ip
and port number at which my openser proxy would be listening). The server
should then send back 200 Ok with the contact header containing the isfocus"
parameter of the form -Contact: <sip:conference1@mediaproxyip;isfocus> The
isfocus is an RFC 4579 based feature. The 200 Ok responses to other invites
(normal calls that do not create conference) should not include this isfocus
in the contact header of 200 Ok.
Finally, the openser proxy should be able to contact the media proxy on
receiving an invite to create the conference and send that ip and focus
information in the 200 Ok. The UA -A would then send a REFER to B and C to
refer to the media server and they disconnect with A. Then all three UAs
would individually send invite to the uri returned in the contact header and
join the conference.
That is not a proxy task, but a SIP application server (probably a
B2BUA) even if it just handles signalling.
--
Iñaki Baz Castillo
<ibc(a)aliax.net>