Hi Eric, Eric wang <eric.wangxr@xxxxxxxxx> Thu, 15 Apr 2010 17:40:17 +0800 >HI Shinji, > >I noticed the chart in your mail showed ,SDP4 and SDP5 both >exist in reliable response(1xx-rel). In my mind, no matter >SDP5 is offer or answer, it shouldn't be allowed. Agree. And I have said the same thing in the original mail. You have misunderstood my mail. > UAC UAS > | F1 INVITE (SDP1) | <-- offer > |-------------------->| > | F2 1xx (SDP2) | > |<--------------------| > | F3 1xx (SDP3) | > |<--------------------| > | F4 1xx-rel (SDP4) | <-- answer > |<--------------------| > | F5 1xx-rel (SDP5) | > |<--------------------| > | F6 1xxl (SDP6) | > |<--------------------| > | F7 2xx INV(SDP7) | > |<--------------------| > | F8 ACK | > |-------------------->| > (PRACK transactions are not shown) > >Shinji: > Just you said "different SDPs(compare with the answer) can > exist in non-reliable response and final 2xx response". > >Eric: > I mean different SDPs may appear in non-reliable response, > because some SERVER may use 1xx with SDP > to play some announcements before foward a call, eg a charge > server "HI guy, you have only 5 minute to communicate", > or, a redirect server "the call is forwarding"! If the server > want to use reliable response, it must use re-INVITE after > the call is established ,for the SERVER cannot send the SDP > in final response from UE-B to UE-A.But if the SERVER > use non-reliable response, the SERVER may use final response > to carry SDP. > > UE-A SERVER UE-B > | - INVITE -> | | > | <-18x------ | | > | | -INVITE -> | > | | | IMO "SERVER" in your chart is B2BUA. Because it sends an original 18x not depended on UE-B. This situation is just a fork. Regards, Shinji >BR > >Eric _______________________________________________ Sipping mailing list https://www.ietf.org/mailman/listinfo/sipping This list is for NEW development of the application of SIP Use sip-implementors@xxxxxxxxxxxxxxx for questions on current sip Use sip@xxxxxxxx for new developments of core SIP
