From RFC 3262 …
3. UAS Behaivor 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. … PRACK is like any other request within a dialog, and the UAS core processes it according to the procedures of Sections 8.2 and 12.2.2 of RFC 3261. A matching PRACK is defined as one within the same dialog as the response, and whose method, CSeq-num, and response-num in the RAck header field match, respectively, the method from the CSeq, the sequence number from the CSeq, and the sequence number from the RSeq of the reliable provisional response. … If a PRACK request is received by the UA core that does not match any unacknowledged reliable provisional response, the UAS MUST respond to the PRACK with a 481 response. If the PRACK does match an unacknowledged reliable provisional response, it MUST be responded to with a 2xx response. … On Thu, Jun 11, 2015 at 4:42 PM, Joel Gerber <joel.ger...@corp.eastlink.ca> wrote: > I'd have to dig up the RFC for PRACKs to comment on that. If the problem is > at that level though, I don't believe that a 481 response is quite right. > > Joel Gerber > Network Operations Specialist - Telephone > Telephone > Eastlink > joel.ger...@corp.eastlink.ca T: 519.786.1241 > > -----Original Message----- > From: sip-implementors-boun...@lists.cs.columbia.edu > [mailto:sip-implementors-boun...@lists.cs.columbia.edu] On Behalf Of Roger > Wiklund > Sent: June-11-15 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. > > On Thu, Jun 11, 2015 at 4:35 PM, Joel Gerber <joel.ger...@corp.eastlink.ca> > wrote: >> Do the Request-URIs line up? >> >> >> Joel Gerber >> Network Operations Specialist - Telephone Telephone Eastlink >> joel.ger...@corp.eastlink.ca T: 519.786.1241 >> >> -----Original Message----- >> From: sip-implementors-boun...@lists.cs.columbia.edu >> [mailto:sip-implementors-boun...@lists.cs.columbia.edu] On Behalf Of >> Roger Wiklund >> Sent: June-11-15 10:34 AM >> To: sip-implementors@lists.cs.columbia.edu >> Subject: Re: [Sip-implementors] 183 with 100rel required, followed by >> 180 with 100rel supported >> >> INVITE >> Contact: "Ville Mex" >> <sip:+46840921234@192.168.254.10:5060;transport=TCP>;tag=120e096f >> >> PRACK on 183 >> Contact: "Ville Mex" >> <sip:+46840921234@192.168.254.10:5060;transport=TCP>;tag=120e096f >> >> PRACK on 180 >> Contact: "Ville Mex" >> <sip:+46840921234@192.168.254.10:5060;transport=TCP>;tag=120e096f >> >> They are identical. >> >> On Thu, Jun 11, 2015 at 4:27 PM, Joel Gerber <joel.ger...@corp.eastlink.ca> >> wrote: >>> I would take a look at the contact header in the INVITE and both PRACKs. >>> >>> Joel Gerber >>> Network Operations Specialist - Telephone Telephone Eastlink >>> joel.ger...@corp.eastlink.ca T: 519.786.1241 >>> >>> -----Original Message----- >>> From: sip-implementors-boun...@lists.cs.columbia.edu >>> [mailto:sip-implementors-boun...@lists.cs.columbia.edu] On Behalf Of >>> Roger Wiklund >>> Sent: June-11-15 9:59 AM >>> To: sip-implementors@lists.cs.columbia.edu >>> Subject: [Sip-implementors] 183 with 100rel required, followed by 180 >>> with 100rel supported >>> >>> Call flow - outgoing call from PBX to ITSP. >>> >>> --> INVITE with 100rel supported >>> <-- 100 trying >>> <-- 183 session progress with 100rel required >>> --> PRACK >>> <-- 200 OK on PRACK >>> <-- 180 ringing with 100rel supported >>> --> PRACK >>> <-- 481 Call leg/transaction does not exist >>> >>> I've checked the To/From tags and the Call-Id, everything is identical. >>> >>> I'm assuming the PBX is doing the correct thing here, it receives a >>> 180 ringing with 100rel supported. >>> >>> Or is there something in the standard saying that if you have PRACKed one >>> provisional response there's no need to do it on subsequent provisional >>> responses? >>> >>> Any idea what the culprit could be? >>> >>> I've opened a ticket with the team running the server that's sending the >>> 481, but I just wanted to check with you guys if there's anything obvious >>> here. >>> >>> Thanks! >>> _______________________________________________ >>> 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 > _______________________________________________ > 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
