Hi, As you noticed (and indicated by the following snippet), the UAS did not send the 180 reliably. Thus the UAC should not have sent PRACK; UAS returning 481 is correct.
RFC 3262 section 3: "The provisional response to be sent reliably is constructed by the UAS core according to the procedures of Section 8.2.6 of RFC 3261. In addition, it MUST contain a Require header field containing the option tag 100rel, and MUST include an RSeq header field. The value of the header field for the first reliable provisional response in a transaction MUST be between 1 and 2**31 - 1." > -----Original Message----- > From: sip-implementors-boun...@lists.cs.columbia.edu [mailto:sip- > implementors-boun...@lists.cs.columbia.edu] On Behalf Of Roger Wiklund > Sent: Thursday, June 11, 2015 10:38 AM > To: sip-implementors@lists.cs.columbia.edu > Subject: Re: [Sip-implementors] 183 with 100rel required, followed by 180 > with 100rel supported > > Yes, the only things that's different is the branch-id in the Via header. > > And the RAck sequence number in the PRACK for the 180. That's 0 1 because > there's no RSeq to copy from. I suspect that's the problem, and the PBX is > the problem here, but I'm not sure. _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
