2010/3/25 hanifa.mohammed <[email protected]>: > As per the below references of RFC3261, >> 18.1.2 Receiving Responses >> >> When a response is received, the client transport examines the top >> Via header field value. If the value of the "sent-by" parameter in >> that header field value does not correspond to a value that the >> client transport is configured to insert into requests, RFC1052 the >> response MUST be silently discarded. > > For any other reason, shall the "sent-by" parameter value be different > in response?
No, never, not at all. It must be the *same* as the sent-by used in the request. > Actually, my client uses a NAT which changes the "sent-by" parameter value > of REGISTER request and the same is reflected in teh 401 response. Guess, > NAT does not revert the changes while forwarding the responses. As always,fucking SIP ALG routers breaking the SIP protocol. http://www.voip-info.org/wiki/view/Routers+SIP+ALG The sent-by is not required to be changed, neither in NAT scenarios!!! The server will compare the IP in sent-by with the real source IP of the request. If it's different the server will add a ";received=PUBLIC_IP" into the response, and route there the response (but to the original port of the sent-by which would not work under NAT, so empty ;rport parameter is also required in the Via of the request). > The problem is that few other clients such as XLite and Mercuro accepts > this response and process it. The problem is the router and its SIP ALG. Destroy it ;) > Is there any references that allows to modify the sent-by parameter of > VIA and thus invalidate the above req of REFC3261? http://tools.ietf.org/html/rfc3261#section-18.2.1 PS: Nobody complains of routers with SIP ALG. It seems that SIP is mostly enclosed in operators private networks in which they also control the routers. Nobody cares about SIP in real internet network. It's really annoying the fact that nobody asks the vendors to stop including SIP ALG (always enabled by default) in their routers. This is a lost battle. -- Iñaki Baz Castillo <[email protected]> _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
