Hi, RFC3262 states following under section 4 "UAC Behaviour"
"Handling of subsequent reliable provisional responses for the same initial request follows the same rules as above, with the following difference: reliable provisional responses are guaranteed to be in order. As a result, if the UAC receives another reliable provisional response to the same request, and its RSeq value is not one higher than the value of the sequence number, that response MUST NOT be acknowledged with a PRACK, and MUST NOT be processed further by the UAC. An implementation MAY discard the response, or MAY cache the response in the hopes of receiving the missing responses." So, you can discard or cache 180. Regards, Mohit On 3/15/16, JC <jc.hu...@tom.com> wrote: > Hi, > > > > There is one SIP call scenario that one SIP UA sends one reliable 183 to > one > SIP device, and the UA receives the PRACK, then, it sends 200OK of PRACK > and > one new reliable 180 immediately. All the messages are sent over UDP, due > to > the network issue, the SIP device receives the 2nd reliable 180 ahead of > PRACK's 200OK. Now, I find the SIP device can't handle the case, and I have > to prove that current case should be handled by it well. > > > > I looked through RFC3262 and not find it clarify the case clearly. So, is > there any other RFC or SPEC which describe it? > > > > Thanks, > > JC > > _______________________________________________ > Sip-implementors mailing list > Sip-implementors@lists.cs.columbia.edu > https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors > _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
