At the very first, the transaction for 1st INVITE would have been created. And when second INVITE comes, since the branch_id is different definitely it will be a different transaction. But it would eventually map to dialog created by first INVITE. But if the SIPProxy supports spiral call flows, the second INVITE might map to second segment of the call flow ( something like post-proxy-B2BUA ) and process the call. But if doesn't support the second segment, then it will be a loop detected scenario and where it would basically reject the second INVITE with 488.
Somesh -----Original Message----- From: sip-implementors-boun...@lists.cs.columbia.edu [mailto:sip-implementors-boun...@lists.cs.columbia.edu] On Behalf Of ext Ashwath Kumar Sent: Sunday, April 19, 2009 2:01 PM To: sip-implementors@lists.cs.columbia.edu Subject: [Sip-implementors] Distinguishing Forked and Looped scenarios atSIP proxy Hi All, I am sending TWO INVITE messages to a proxy . ===================== 1st INVITE ========================== INVITE sip:2...@1.20.20.33:5060 SIP/2.0 Via: SIP/2.0/UDP 1.1.1.25:7766;branch=z9hG4bK-22034-1-0 From: sipp <sip:s...@1.1.1.25:7766>;tag=22034SIPpTag001 To: sut <sip:2...@1.20.20.33:5060> Call-ID: 1-22...@1.1.1.25 CSeq: 1 INVITE Contact: <sip:s...@1.1.1.25:7766;transport=UDP> Max-Forwards: 70 Subject: Performance Test Content-Type: application/sdp Content-Length: 206 v=0 o=TestSystemsSIP-GW-UserAgent 8345 6736 IN IP4 9.6.3.11 s=SIP Call t=0 0 m=audio 18570 RTP/AVP 0 19 c=IN IP4 145.253.131.140145.253.131.141 a=rtpmap:0 PCMU/8000 a=rtpmap:19 CN/8000 a=ptime:20 ================2nd INVITE======================== INVITE sip:2...@1.20.20.33:5060 SIP/2.0 Via: SIP/2.0/UDP 1.1.1.25:7766;branch=z9hG4bK-22034-1-1 From: sipp <sip:s...@1.1.1.25:7766>;tag=22034SIPpTag001 To: sut <sip:2...@1.20.20.33:5060> Call-ID: 1-22...@1.1.1.25 CSeq: 1 INVITE Contact: <sip:s...@1.1.1.25:7766;transport=UDP> Max-Forwards: 70 Subject: Performance Test Content-Type: application/sdp Content-Length: 206 v=0 o=TestSystemsSIP-GW-UserAgent 8345 6736 IN IP4 9.6.3.11 s=SIP Call t=0 0 m=audio 18570 RTP/AVP 0 19 c=IN IP4 145.253.131.140145.253.131.141 a=rtpmap:0 PCMU/8000 a=rtpmap:19 CN/8000 a=ptime:20 =========================== These two are distinguised by only one parameter that is branch=z9hG4bK-22034-1-1 in via header. Now how the proxy will consider this ? Will Proxy treat it as loop ? or will it treat as an INVITE from some other UA , as in case of forked scenario ? Thanks Ash, _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
