This is a protocol question, I don't know if it is directly related to ser. Concerning the Via tags, should any proxy/gateway modify tags that don't belong to it, or should they simply be copied verbatum?
For example, I have a situation where I send an INVITE message, and the TRYING response I receive modifies one of the Via: tags. I don't think this is right. Here are the two packets in question:
# U 2003/02/19 18:36:20.276844 164.9.42.25:5060 -> 184.294.324.2:5060 INVITE sip:12143357976@184.294.324.2:5060 SIP/2.0. Max-Forwards: 10. Record-Route: sip:12143357976@164.9.42.25;branch=0. From: sip:8178863582@216.87.145.22 ;tag=d8579116-fdc-3e542303-23d34-4a84. To: sip:12143357976@augustvoice.net ;user=phone. Call-ID: 59fd88-d8579116-fdc-3e542303-23d2f-3897@216.87.145.22. CSeq: 2 INVITE. Via: SIP/2.0/UDP 164.9.42.25;branch=z9hG4bKcc26.d3c125d.0. Via: SIP/2.0/UDP 216.87.145.22:4060 ;branch=z9hG4bK-3e542304-23dfc-ea2. Contact: sip:8178863582@216.87.145.22:4060. User-Agent: FXS_GW (sip1028a.bin). Content-Type: application/SDP. Content-Length:291. P-hint: LD GATEWAY. . v=0. o=FXS_GW 12367 0 IN IP4 216.87.145.22. s=Audio Session. i=Audio Session. c=IN IP4 216.87.145.22. t=0 0. m=audio 16384 RTP/AVP 0 18 4 8 96. a=fmtp:96 0-11. a=rtpmap:0 PCMU/8000/1. a=rtpmap:18 G729/8000/1. a=rtpmap:4 G723/8000/1. a=rtpmap:8 PCMA/8000/1. a=rtpmap:96 telephone-event/8000.
And your response is: # U 2003/02/19 18:36:20.902858 184.294.324.2:5060 -> 164.9.42.25:5060 SIP/2.0 100 Trying . Via: SIP/2.0/UDP 164.9.42.25;branch=z9hG4bKcc26.d3c125d.0. Via: SIP/2.0/UDP 216.87.145.22:4060. From: sip:8178863582@216.87.145.22 ;tag=d8579116-fdc-3e542303-23d34-4a84. To: sip:12143357976@augustvoice.net ;user=phone;tag=27DC1DCC-F61. Date: Thu, 20 Feb 2003 00:36:20 GMT. Call-ID: 59fd88-d8579116-fdc-3e542303-23d2f-3897@216.87.145.22. Server: Cisco-SIPGateway/IOS-12.x. CSeq: 2 INVITE. Allow-Events: telephone-event. Content-Length: 0. .
See how the : Via: SIP/2.0/UDP 216.87.145.22:4060 ;branch=z9hG4bK-3e542304-23dfc-ea2. Has been changed to: Via: SIP/2.0/UDP 216.87.145.22:4060.
Does anyone have any perl script to take a ngrep protocol dump and print it out in a pretty way?
---greg Greg Fausak August.Net Services, LLC