Hi, If you want to use a different SDP in 200 OK you need to use a different To tag. You can not "update" an answer within the same dialog by sending a new SDP in 200 OK.
Regards, Christer ________________ Reply Header ________________ Subject: RE: [Sip] PRACK query Author: [EMAIL PROTECTED] Date: 29th September 2006 7:07:48 pm SDP in 1xx response and 200 OK can be different because of early media announcements and actual calle connected. If 200 OK SDP will be same, then how can early media will be differentiated with regular session (basically early media is used for announcements and 200 OK will tell the actual callee connected) Regards, Udit "Christer Holmberg \(JO/LMF\)" <[EMAIL PROTECTED]> 09/28/2006 07:46 PM To Udit Goyal/C/US/[EMAIL PROTECTED], <[email protected]> cc [email protected] Subject RE: [Sip] PRACK query Hi, >Please let me know if my understanding is correct for regular session offer-answer when PRACK is used: > >For INVITE containing SDP, and if offer answer done in the using reliable 183 response for early media, 200 OK response SDP will have an answer for the >regular session, so 200 OK SDP will be answer to the offer sent in initial SDP. Yes. Of course, since you have already received the answer reliably, you really don't need to care about the SDP in 200 OK, but according to the rules it should be the same as previously sent in 18x. >Similarly, if INVITE does not have SDP, and if offer-answer done using PRACK, still 200 OK will contain the regular session offer and answer will be >present n the ACK message. I would assume so, yes. But, again, you don't really need to care. >Similarly, if UPDATE is used for offer-answer before call is connected, it will not affect the regular session offer-answer, it will be taken care by >initial INVITE , final 200 OK and ACK message. I don't know what you mean by "not affect". If you send an offer in INVITE, and receives an answer in a reliable 18x, the offer/answer exchange in UPDATE will then replace the one previously done. But, yes, the SDP you get in the 200 OK should still be the same that you got in 18x, even if you have performed offer/answer exchanges after that. At least this is how I understand it - but you can never be sure when it comes to offer/answer :) Regards, Christer _______________________________________________ Sip mailing list https://www1.ietf.org/mailman/listinfo/sip This list is for NEW development of the core SIP Protocol Use [email protected] for questions on current sip Use [email protected] for new developments on the application of sip _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
