Hi Vineet, Stateless proxy cannot distinguish a retransmission since it does not maintain any transaction. For stateless proxy, RFC 3261 states that
16.11 Stateless Proxy When acting statelessly, a proxy is a simple message forwarder. Much of the processing performed when acting statelessly is the same as when behaving statefully. The differences are detailed here. A stateless proxy does not have any notion of a transaction, or of the response context used to describe stateful proxy behavior. Instead, the stateless proxy takes messages, both requests and responses, directly from the transport layer (See section 18). As a result, stateless proxies do not retransmit messages on their own. They do, however, forward all retransmissions they receive (they do not have the ability to distinguish a retransmission from the original message). regards, Aman Aggarwal Aricent -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Shanbhag, Somesh (NSN - IN/Bangalore) Sent: Monday, April 30, 2012 10:59 AM To: ext Vineet Menon; [email protected] Subject: Re: [Sip-implementors] detect retransmitted messages.. Hi Vineet, As far as stateful transaction is concerned, I think, call-id would give a clear enough picture of a retransmitted message, but what if it's a new invite for capability negotitation??? [Answer] The re-INVITE shall have the incremented CSeq number and the retransmission shall not have. This is because retransmission is normally done by Transaction layer in Stateful case. Regards, Somesh -----Original Message----- From: [email protected] on behalf of ext Vineet Menon Sent: Mon 4/30/2012 10:32 AM To: [email protected] Subject: [Sip-implementors] detect retransmitted messages.. Hi, I wanted to know is there a way to detect a retransmitted message in a stateless and statefull proxy? As far as stateful transaction is concerned, I think, call-id would give a clear enough picture of a retransmitted message, but what if it's a new invite for capability negotitation??? How to detect this in a stateless transaction?? Regards, Vineet Menon _______________________________________________ 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 =============================================================================== Please refer to http://www.aricent.com/legal/email_disclaimer.html for important disclosures regarding this electronic communication. =============================================================================== _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
