Ranga, Basically UACs and UASs set the tags and proxies do not.
The UAC assigns the from-tag. RFC 3261 requires the UAC to include a from-tag in all requests. A forking proxy copies the from-tag in the received request to all of its outgoing requests. If the original request does not have a to-tag, the UAS will assign the to-tag and include it in the response. A proxy acting as the UAS when generating a non-2xx final response would assign a to-tag in that response (e.g. when it cannot forward the request or never receives a response). However, if the proxy is forwarding the "best" non-2xx final response from those received from downstream elements, it should retain the to-tag from that response. For requests within a dialog, the from and to tags in the dialog establishing request & response are used. cheers, (-:bob Robert F. Penfield Chief Software Architect Acme Packet, Inc. 130 New Boston Street Woburn, MA 01801 [EMAIL PROTECTED] ----- Original Message ----- From: "M. Ranganathan" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, October 23, 2002 9:39 AM Subject: [Sip-implementors] MUST all RFC 3261 Requests have From tags? > Hello! > > I am trying to figure out whether from tag assignment for all outgoing > requests is mandatory for RFC 3261 compatible stacks ? Is this mandatory > for forked requests? > > Thanks > > Ranga. > > -- > > M. Ranganathan > N.I.S.T. Advanced Networking Technologies Division > 100 Bureau Drive, Stop 8920, Gaithersburg, MD 20899 > Tel:301 975 3664; fax:301 590 0932 > > Advanced Networking Technologies for the people! > > > _______________________________________________ > Sip-implementors mailing list > [EMAIL PROTECTED] > http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors > _______________________________________________ Sip-implementors mailing list [EMAIL PROTECTED] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
