Hi Jason Penton, UA1 is wrong. to UA3??? Proxy should just Forward the message .Proxy should not change the to-tag. Thanking you, Regards, Sreeram Phone: 8520408 Ex:3208 -----Original Message----- From: sip-implementors-bounces(a)cs.columbia.edu [mailto:sip-implementors-bounces@cs.columbia.edu] On Behalf Of Jason Penton Sent: Thursday, April 01, 2004 1:29 PM To: sip-implementors(a)cs.columbia.edu Cc: serdev(a)lists.iptel.org; serusers(a)lists.iptel.org Subject: [Sip-implementors] FW: Forking Proxy Hi All Sorry about the last post - I have attached the call flow as an image this time :-) I have a question about the CORRECT operation of UA when making a call via a forking proxy: (see attached image for call flow) Lets say UA1 calls 7000(a)sip.com and user 7000(a)sip.com is available at UA2 and UA3 i.e. the Proxy forks the request. * UA1 is using the to-tag of the first 180 RINGING it received (frame 5) no matter what the to-tag in the 200 OK is * My question here is: who is in the wrong???? The proxy or UA1? * Should the proxy change the to-tag of the ACK before forewarding it to UA3??? Jason Penton Rhodes University Grahamstown South Africa Confidentiality Notice The information contained in this electronic message and any attachments to this message are intended for the exclusive use of the addressee(s) and may contain confidential or privileged information. If you are not the intended recipient, please notify the sender at Wipro or Mailadmin(a)wipro.com immediately and destroy all copies of this message and any attachments.