It sounds like you may be confusing rfc3261 defined "dialog" with the rfc5057 defined "dialog usage".
RFC 3261 indicates a "dialog is identified by a call identifier, local tag, and a remote tag". See rfc5057 for details concerning multiple dialog usages within a dialog. The following thread concerning REFER within INVITE and subscription usages may be interest. http://www.ietf.org/mail-archive/web/sip/current/msg27045.html > -----Original Message----- > From: [email protected] [mailto:sip- > [email protected]] On Behalf Of isshed > Sent: Tuesday, April 26, 2011 4:15 AM > To: sip-implementors > Subject: [Sip-implementors] Call Transfer Using REFER > > Hello All, > > I want to implement call transfer feature on a user agent. As you all > know > it can be done in 2 way. 1. sending REFER out of dialog and 2. sending > REFER > in dialog. As rfc 3515 says " > > A REFER request MAY be placed outside the scope of a dialog created > with an > INVITE. " > > Also as per RFC 3515 " A REFER request implicitly establishes a > subscription > to the refer event. " > > My first doubt is if REFER is outside of the dialog created by INVITE > can it > be in a dialog created by SUBSCRIBE. Or in this case there will be 3 > dialogs? > > My second doubt is if REFER is inside the dialog created by INVITE can > it be > in a dialog created by SUBSCRIBE too. Or in this case there will be 2 > dialogs(1 for invite and 1 for subscribe)? > Can you all please help me understand this? > > Thanks, > _______________________________________________ > 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
