Hi, >> I don't disagree with what people are saying, but trying to read it >> from a I-am-a-new-implementor-and-I-would-like-to-get-it-right-from- >> the-beginning perspective I don't think anything is clarified. Eg. >> talking about that an SDP sent after the answer would be >> "missunderstood as a new offer" is confusing. > > I guess "missunderstood as a new offer" issue is clear: > If the session-id of o= line is the same the ANSWER, UAC can treate it as just COPY of the answer; > If the session-id is higher than the ANSWER's session-id, the UAC can treate it as *new* offer. As the UAC MUST ignore any SDP after ANSWER, it is OK for UAC doing nothing. But if UAC checks the SDP and find it is > *new* offer and violation of O/A rules then terminate the session, I also think it is also OK(UAS do bad behavior at first). I am not talking about the UAC procedure. I fully support saying that the UAC ignores the SDP. My problem is to say that the UAS shall not include SDP, because the UAC could "missunderstand it as a new offer". All we need to say is that the UAS MUST NOT include a new SDP. Regards, Christer > > -----Original Message----- > > From: sipping-bounces@xxxxxxxx > > [mailto:sipping-bounces@xxxxxxxx] On Behalf Of OKUMURA Shinji > > Sent: 21. huhtikuuta 2010 8:45 > > To: sipping@xxxxxxxx > > Subject: Re: [Sipping] Is SDP in an unreliable response "the > > answer" ??? > > > > Hi, > > > > Hans Erik van Elburg <ietf.hanserik@xxxxxxxxx> Tue, 20 Apr > > 2010 21:53:17 +0200 > > >On Tue, Apr 20, 2010 at 3:47 PM, Paul Kyzivat > > <pkyzivat@xxxxxxxxx> wrote: > > >> Here is my attempt at summarizing the discussion conclusions: > > >> > > >> Normative things (stated or implied in existing RFCs): > > >> > > >> - If the UAC sent an offer in the INVITE, then after it > > receives SDP > > >> (the > > >> answer) in a reliable response to the INVITE, any SDP in > > subsequent > > >> responses to the INVITE MUST be ignored. > > >> > > >> - Further, if SDP is received in an unreliable response to > > the invite > > >> prior to receiving SDP in a reliable response, then it MUST be > > >> treated as the answer for purposes of media processing, > > but not for > > >> purposes of determining when another offer may be sent or received. > > >> > > >[HE] I miss what the UAC should do in this case for subsequent > > >responses, does the following hold as well: > > >"If the UAC sent an offer in the INVITE, then after it receives SDP > > >(the answer) in an unreliable response to the INVITE, any SDP in > > >subsequent responses to the INVITE MUST be ignored/granted/... ." ? > > > > I agree. And it's certainly "ignored". > > > > >Regardless what the correct behaviour is, it is missing in > > your summary. > > > > > >> - if the UAS receives an offer in the INVITE, it MUST NOT > > include SDP > > >> in any response it sends until it has determined the > > intended answer > > >> SDP to the offer. > > >> > > >> - once the intended answer SDP is determined, it MUST be sent in a > > >> reliable response to the INVITE. It MAY be sent in one or more > > >> *preceding* unreliable provisional responses. > > >> > > >> Non-normative, best practice suggestions: > > >> > > >> - if the UAS receives an offer in the invite, once it has sent the > > >> answer in a reliable response, it should not send any SDP in > > >> subsequent responses to the INVITE. > > _______________________________________________ > > 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 > > > _______________________________________________ > 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 > -------------------------------------------------------- ZTE Information Security Notice: The information contained in this mail is solely property of the sender's organization. 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