If a Request has reached a node(B2BUA/proxy) which is responsible for contact routing, it may/can ignore the Max forwards and route it to the Registered Contact.
So it is just a matter of strict implementation versus providing the Functionality. Kasturi _____ From: Subramanya [mailto:[EMAIL PROTECTED] Sent: Wednesday, November 15, 2006 8:30 AM To: Kasturi Narayanan Cc: sip-implementors; ysong Subject: Re: [Sip-implementors] FW: Query on max-forwards counts When a request reaches the proxy, if mf becomes 0 once proxy decrements the mf,then it means it has already hopped n number of times right, then why proxy should send to next hop. i mean, see this example where mf is 5 mf=5 mf =4 mf =3 mf =2 mf =1 mf =0 UA1--> Proxy A--> Proxy B--> Proxy C-->Proxy D--> Proxy E-->UA2 Now at Proxy E mf is 0, means it has already visited 5 nodes, so it shdn't be forwarded anymore,so proxy E shd return with 483 response. Please correct me if i am wrong. -Subramanya Kasturi Narayanan wrote: The approach suggested by Robert Sparks solves the problem but creates an un-necessary hop when the sender knows for sure that it going to be dropped by the Receiver (since it is sending with mf=0). Kasturi -----Original Message----- From: Song, Youngsun [mailto:[EMAIL PROTECTED] Sent: Monday, November 13, 2006 9:22 AM To: [email protected] Subject: [Sip-implementors] FW: Query on max-forwards counts Hi, Please see the attached response from Robert Sparks regarding this query. (FYI, I had also sent him a separate email...) Per his response, Proxy-B should forward the request to UA-B. Thanks to all who has taken the time to respond to my query, YoungSun -----Original Message----- From: Robert Sparks [mailto:[EMAIL PROTECTED] Sent: Monday, November 13, 2006 9:12 AM To: Song, Youngsun Subject: Re: [Sip-implementors] Query on max-forwards counts See page 95, item 3. You reject when you receive, not before you send. You reject when you receive a max-forwards of 0, not when you receive a max-forwards of 1. RjS -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Song, Youngsun Sent: Friday, November 10, 2006 11:19 AM To: [email protected] Subject: [Sip-implementors] Query on max-forwards counts Hi, I have a clarification question on the following statement in Section 8.1.1.6 of RFC3261 regarding when a proxy should send a 483 and whether the number of hops includes the destination hop. "The Max-Forwards header field serves to limit the number of hops a request can transit on the way to its destination. It consists of an integer that is decremented by one at each hop. If the Max-Forwards value reaches 0 before the request reaches its destination, it will be rejected with a 483(Too Many Hops) error response." Consider the following flow: (mf=max-forwards) UA-A --- INVITE (mf=2) ---> Proxy-A ---- INVITE (mf=1) ---> Proxy-B ---- INVITE (mf=0) ---> UA-B In the flow above, should Proxy-B forward the INVITE with max-forwards=0 to UA-B or should it reject the request with 483? Thanks for your help in advance, YoungSun _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implemento rs _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
