[Sip-implementors] Re: Doubt in the INVITE

[Jerry Ipe Thomas]

Hi Balaji! Via is the header to look for if you're looking for host address or FQDN and transport port!   For Example, Via: SIP/2.0/UDP 213.168.113.234:5182;branch=z9hG4bK-65656521-5285145-543216-62367035689-12756045645 Via: SIP/2.0/UDP 197.31.79.101:8037;branch=z9hG4bK-5952490521345-235216234-354234124-213725301-54236 Via: SIP/2.0/UDP 203.68.197.7:5160;branch=z9hG4bK-4432485324051204-5632-54321423-53563-65306230-6434 Transport is UDP, IP address is 203.68.197.7 and transport port is 5160. Some implementations use B2B UAs. Separate dialogs are maintained for each side of the call i.e   [UA]<----DIALOG 1----->[SERVER]<----DIALOG 2----->[UA/PROXY]   As long as you are the outbound proxy or the first proxy, away from the UA, you can know the host address and transport port. Otherwise, you've got a hope in hell of getting it! If behind a NAT, you can try the SDP origin field also, but be warned that most implementations change that also!   If I'm wrong please do correct me. I'll be happy to hear from you if I'm wrong about this. :-) Regards,   Jerry Ipe Thomas Trainee Engineer(R&D) D-Link India Ltd. Software and R&D Center #65, 35th Main, 100ft. Ring Road, 2nd Stage, B.T.M Layout, Bangalore-560068 Tel: +91-80-26788350/51 Extn: 117   -----------Original Message-------------- Date: Fri, 27 Feb 2004 18:47:59 -0800 (PST) From: Balaji Thoguluva <[EMAIL PROTECTED]> Subject: [Sip-implementors] Doubt in the INVITE To: [EMAIL PROTECTED] Message-ID: <[EMAIL PROTECTED]> Content-Type: text/plain; charset="us-ascii" Hi,        I am a Master's student studying at University of Kentucky. I would like to know which header field I have to look in the forwarded INVITE message (at some proxy) to determine who exactly sent the INVITE message (which UAC created the first INVITE). I am not sure the Contact header field tells that. I would appreciate your guidance.   Thanks, Balaji

_______________________________________________
Sip-implementors mailing list
[EMAIL PROTECTED]
http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors