I have doubt in this case. If proxy not retransmit non-2XX final responses to a TCP UAC, then What is difference between transport over UDP and TCP?
I think TCP i.e. at Transport layer sends data reliably (Retransmits if not received Acknowledgement for TCP packet) irrespective of Application layer (i.e. SIP at Application layer or anything else). Correct me if I am wrong. Regards Sesh -----Original Message----- From: sip-implementors-boun...@lists.cs.columbia.edu [mailto:sip-implementors-boun...@lists.cs.columbia.edu] On Behalf Of Iñaki Baz Castillo Sent: Sunday, January 16, 2011 7:45 AM To: RahulSrivastava 71616 Cc: sip-implementors@lists.cs.columbia.edu Subject: Re: [Sip-implementors] Query 2011/1/14 RahulSrivastava 71616 <rah...@huawei.com>: > I have a basic query for stateless proxy: > Consider a stateless proxy transfers INVITE from TCP to UDP. > If a non 2xx response is recieved on UAS which is on UDP, do proxy needs to > take care of retransmissions of > non 2xx of INVITE i.e. > if UAS (which is on UDP) retransmits non 2xx of INVITE do proxy needs to eat > it up or blindly transfer on TCP? > > (From RFC I can get 2xx response are retransmitted end to end.) I think same > logic should apply for non 2xx but not sure. Can anybody please help? > Any documents which describes transport conversion functionality for > transport conversion. RFC 3261 - 17.2.1 INVITE Server Transaction While in the "Proceeding" state, if the TU passes a response with status code from 300 to 699 to the server transaction, the response MUST be passed to the transport layer for transmission, and the state machine MUST enter the "Completed" state. For unreliable transports, timer G is set to fire in T1 seconds, and is not set to fire for reliable transports. This is a change from RFC 2543, where responses were always retransmitted, even over reliable transports. So the answer is not, the proxy must not retransmit non-2XX final responses to a TCP UAC. -- Iñaki Baz Castillo <i...@aliax.net> _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
