You are absolutely correct about RFC 3261. In regard of RFC 2543 the situation is a bit more tricky, since it never properly defines what matching To and From headers is supposed to mean. It does talk about saving complete To and From headers in the dialog state as local and remote addresses, and about matching those values against the To and From headers of the incoming requests.
It would be safer to store complete headers in dialog state and reusing them in subsequent requests, unless the client specifically allows (and you have a compelling need) to change them. On the other hand, if client does not store and use header parameters in subsequent dialog requests, it should still be RFC 3261 compliant. This situation almost looks like RFC 3261 bug, since the intent of this specification is to be backward compatible with RFC 2543. Since header parameter are very rare, I don't think this affects a lot of implementation and probably because of of this are not properly covered in RFC 3261. ____________________________ Roman Shpount www.telurix.com Date: Fri, 19 Feb 2010 13:51:30 -0800 > From: Anders Kristensen <[email protected]> > Subject: Re: [Sip-implementors] Query - are *header* parameters (other > than tag) of From and To part of dialog state? > To: [email protected] > Message-ID: <[email protected]> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > Section 12.2.1.1 of 3261 talks about how the UAC constructs mid-dialog > requests and it concerns itself with how From and To *URI* and tags are > set. There's nothing in there suggesting that header parameters MUST or > even SHOULD be retained. The part about 2543 compatibility also does > not talk about header parameters. IMHO only the dialog state matters and > that does not include the full From and To header fields. > > Thanks, > Anders > _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
