Jeroen wrote: >A proxy can "send" (in the sense of initiate, not only forward) CANCEL and >ACK for non-2xx, so technically it can send requests.
True. What I should have written is probably "a proxy can not send subsequent requests". > A "pure" proxy would not initiate other requests such as BYE, but "hybrid" proxies (i.e. those acting as proxy but also as a special kind of UA) do. There is nothing like a "pure" Proxy. Either it _is_ a proxy, or it is not. Simple as that. And my question was about a proxy. >The dialog state would be needed to construct e.g. a BYE request that >arrives at and is accepted by one or both parties in the call (it needs to >have the proper call-id, tags, route headers, CSeq, etc). Typically this is >done to enforce certain policies in some network environments. In this case you are probably describing a B2BUA (at least not a proxy) and in this case I _do_ understand why it need the dialog information. The answers I have got so far have not been answers to my original question, but instead answers to other questions that I either already know the answer to, or questions in directions that I am not at all interested (like half-pure-almost-proxys-that-actually-are-B2BUAs-in-a-telco-system problems) So one again, cause I am really curious for the answer: What is the reason a proxy would want to be dialog stateful given that a proxy can't send requests (other than CANCEL, and ACK)? Why would anyone like to build a dialog stateful proxy? In what way could a dialog stateful proxy use the information in the dialog that it has saved? / Christian Jansson _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
