Assume if PRACK is sent in this scnario , the offer/answer will be different, as SDP body in the PRACK is optional , and if a SDP body is sent in the PRACK then the immediate response of that PRACK must contain an answer.
For Eg: INVITE (Offer1) 18x (Answer1) PRACK (Offer) 2xx PRACK (Answer) UPDATE (Offer2) 2xx UPDATE (Answer2) 2xx INVITE (Offer3) /* This will be a new offer again */ ACK INVITE (Answer3) Thanks and Regards, Geetha --- Brett Tate <[EMAIL PROTECTED]> wrote: > > To my understanding , > > In the scenario mentioned by you. > > INVITE (Offer1) > > 18x (Answer1) > > UPDATE (Offer2) > > 2xx UPDATE (Answer2) > > 2xx INVITE (Offer3) /* This will be a new offer > again */ > > ACK INVITE (Answer3) > > > > So an answer for offer3 needs to be sent in ACK. > > Within your example (assuming PRACK used but not > shown), the SDP within > INVITE 2xx must be ignored. Thus it is not an > offer; and there would > not be an answer within the ACK. > > > > > *Hi All,* > > > * Can U corect me, If i am wrong....* > > > ** > > > *Assume the UAC receives the SDP (answer_1) in a > > > > reliable 18x. After that, is sends eg an UPDATE > with > > > a new offer, and receives a new(answer_2) in the > > > UPDATE response. Then, INVITE 200 OK is > received, > > > from the same UAS. > > > Now, to my understanding the SDP in the > > > INVITE 200 OK response shall still be the one > > > first sent, ie answer_1, but since that is now > not > > > "valid" anymore (since answer_2 has been > received after > > > that) the UAC shall not use > the SDP received > in > > > the 200. Instead it shall use the > > > latest answer, ie answer_2. > > The SDP within INVITE 2xx must be ignored. Vendors > which place the > useless SDP within the INVITE 2xx generally do so > for perceived > interoperability reasons with devices not yet > compliant to rfc3261. > Based upon rfc analysis after SIPit 21, the SIP > working group appears to > have agreed that the useless SDP is not required to > be SDP from the > reliable 18x; thus it may be the SDP resulting from > UPDATE. > > Many answers concerning offer/answer can be found > within > draft-ietf-sipping-sip-offeranswer. > > > _______________________________________________ > Sip-implementors mailing list > [email protected] > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors > DELETE button is history. Unlimited mail storage is just a click away. Go to https://edit.india.yahoo.com/config/eval_register _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
