Louis, I believe the answer is that CANCELs are hop-by-hop requests...
>From section 9: A stateful proxy responds to a CANCEL, rather than simply forwarding a response it would receive from a downstream element. For that reason, CANCEL is referred to as a "hop-by-hop" request, since it is responded to at each stateful proxy hop. And from section 9.2: The processing of a CANCEL request at a server depends on the type of server. A stateless proxy will forward it, a stateful proxy might respond to it and generate some CANCEL requests of its own, and a UAS will respond to it. See Section 16.10 for proxy treatment of CANCEL. Though section 16.11 says that CANCEL requests received and then forwarded by a STATELESS proxy will have multiple Via: Stateless proxies MUST NOT perform special processing for CANCEL requests. They are processed by the above rules as any other requests. In particular, a stateless proxy applies the same Route header field processing to CANCEL requests that it applies to any other request. So basically, as a Client sending a CANCEL, don't make any assumption whether you are sending to a STATELESS or STATEFUL proxy, is that right? --Louis -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Kaixuan Liu Sent: Thursday, March 31, 2005 8:02 AM To: [email protected] Subject: [Sip-implementors] doubt on CANCEL via hi, Section 9.1 of RFC3261 says that >A CANCEL constructed by a client MUST have only >a single Via header field value matching the >top Via value in the request being cancelled. why couldn't it contain all the Via? thanks, Louis _______________________________________________ Sip-implementors mailing list [email protected] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors This e-mail and any attachment is for authorised use by the intended recipient(s) only. It may contain proprietary material, confidential information and/or be subject to legal privilege. It should not be copied, disclosed to, retained or used by, any other party. If you are not an intended recipient then please promptly delete this e-mail and any attachment and all copies and inform the sender. Thank you. _______________________________________________ Sip-implementors mailing list [email protected] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
