2008/10/2, Harsha. R <[EMAIL PROTECTED]>: > Its not clear to me as to why the 18X is expecting a Contact. The purpose of > Contact is to do a target refresh. > 18X missing a Contact header means a target refresh has not happened. In > this case, address the PRACK to > the original remote target( mostly the one used for INVITE). > > If all goes well, PRACK reaches the intended UAS and call goes through;
I don't agree here. The purpose of an-indialog request is to arrive just to the UAS in that dialog, not to others UAS with same AoR. If you send a PRACK (in-dialog request) with the same RURI as the initial INVITE then the proxy between UAC and UAS must do again a lookup to change the RURI and possibly do parallel forking. This will cause an in-dialog request arriving to other UAS registered with same AoR, each of them will reply "482 Call/Leg doesn't exist". IMHO that is not the purpose SIP was designed, maybe it's just a black hole, "legal", but incorrect. If we keep as "valid" any exotic possibility not strictly defined in the RFC's then SIP would become a pain. -- Iñaki Baz Castillo <[EMAIL PROTECTED]> _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
