From: Ramesh <[EMAIL PROTECTED]> Here is another question I have with regard to Usage of REFER in 3pcc. If we have started a OOD-REFER and wish to CANCEL the dialog; ie the originator of the dialog wishes the cancel the Dialog. Can I send a CANCEL message if we have not received a confirmation 2xx message and a BYE message if we have received a dialog Confirmation. I haven't seen anything in the RFC the explicitly forbids me from doing it.
To consolidate and extend what others have said: If you want to stop the REFER itself from taking effect, you can send a CANCEL for it. But you can't send a CANCEL until you get a provisional response for the REFER, and you don't usually get one. And even if you can send a CANCEL, the other end isn't required to honor it. Once the other end has accepted the REFER, you are participating in a refer dialog usage with it, which is the same as a subscription dialog usage for the "refer" package. You can terminate that usage by sending a re-SUBSCRIBE with "Expires: 0". If you want to terminate the INVITE that was generated by the other end due to receiving the REFER, you have to send a REFER with "Refer-To: xxx?method=BYE". (Since CANCEL isn't an ordinary method, I don't expect "...?method=CANCEL" to work.) You also have to use Target-Dialog to specify the dialog identifiers of the dialog established by the generated INVITE. You can get those by subscribing to dialog events at either end of the INVITE. (They might be returned in the NOTIFYs as well.) Dale _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
