I'm not sure what you asking about; however ... RFC 3261 requires tags to form a dialog; RFC 2543 did not require tags to form call legs. I don't recall the exact RFC 3261 wording concerning interoperability with RFC 2543 devices; however if you don't want to interoperate with such devices, you can reject or release the calls when needed. This might include sending ACK and BYE without a To tag.
If your are still talking about early dialogs, the early dialog was created by receiving a 18x with To tag. The caller can send BYE over an early dialog. ________________________________________ From: [email protected] [[email protected]] On Behalf Of Pavesi, Valdemar (NSN - US/Irving) [[email protected]] Sent: Tuesday, July 26, 2011 3:45 PM To: ext Iñaki Baz Castillo Cc: [email protected] Subject: Re: [Sip-implementors] BYE before call answer " 15.1 Terminating a Session with a BYE Request 15.1.1 UAC Behavior A BYE request is constructed as would any other request within a dialog, as described in Section 12 " If there are no DIALOG how we can build the BYE . ( where is to-tag ). _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
