Leonid, What the UAS needs to ensure here, is that the UAC got its answer (or offer) in the 2xx to the reINVITE. Before it receives the ACK it cannot be certain of that, so a new reINVITE should be refused.
It would probably be better to send a 491 Request Pending, to set the UAC's random backoff timer. I agree that the text in RFC3261 is not clear on this point Regards, Jeroen ----- Original Message ----- From: "Leonid Fainshtein" <[EMAIL PROTECTED]> To: "Jeroen van Bemmel" <[EMAIL PROTECTED]> Cc: <[email protected]> Sent: Sunday, May 21, 2006 8:24 AM Subject: RE: [Sip-implementors] Miss-ordered re-INVITE request In section 14.2 of RFC-3261 written the following: A UAS that receives a second INVITE before it sends the final response to a first INVITE with a lower CSeq sequence number on the same dialog MUST return a 500 (Server Internal Error) response to the second INVITE and MUST include a Retry-After header field with a randomly chosen value of between 0 and 10 seconds. In my scenario the UAS has sent the final response and waiting for the confirmation (ACK)... So it is not exactly the same case as described in 14.2.... Leonid -----Original Message----- From: Jeroen van Bemmel [mailto:[EMAIL PROTECTED] Sent: Saturday, May 20, 2006 9:39 PM To: Leonid Fainshtein Cc: [email protected] Subject: Re: [Sip-implementors] Miss-ordered re-INVITE request Leonid, It MUST send a 500 response with Retry-After, see RFC3261 section 14.2. Furthermore, if it doesn't receive the ACK it SHOULD generate a BYE Regards, jeroen ----- Original Message ----- From: "Leonid Fainshtein" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Saturday, May 20, 2006 9:24 PM Subject: [Sip-implementors] Miss-ordered re-INVITE request > Hi, > > Is the following UAS behavior correct? > > UA-1 UA-2 > ------INVITE ---------> > <------200 ------------ > ------- ACK ----------> > ------ re-INVITE-1-----> > <------200 ------------ > > ------ re-INVITE-2-----> > <------ 400( with Retry-After header) ---- > > As you can see, the second re-INVITE arrives to the UAS when the > previous re-INVITE transaction is not confirmed yet (ACK is not > received). > What should UAS do in this situation? Silently ignore re-INVITE2? Reject > it with response 400 or 500? > Thanks, > Leonid > > _______________________________________________ > Sip-implementors mailing list > [email protected] > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
