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Re: [Sip] What's the difference between session and dialog in SIP?
At 04:44 AM 4/25/2008, Donald Lee wrote:
>old good questions in sip, also add another "transaction".
>
>
>On Fri, Apr 25, 2008 at 8:18 AM, å?å®?å??
><<mailto:szj087 at gmail.com>szj087 at gmail.com> wrote:
>Hi, Vijay
>
>Thanks very much for your timely answers.
>
> From this specification, session is a combination of signaling plane
>and media plane messages and processes that enable two or more
>participants to communicate. I think session is a larger scope than
>dialog. In another word, one session can contain more than one dialog.
>Is what I understand right?
A SIP dialog has the one Call-ID. If more than
one session is involved in the same Call-ID, then
more than one session is within the same
dialog. At issue, I think, is there is little
tying any particular SDP session to a particular
SIP Call-ID. This creates confusion telling the difference between the two.
>Zongjun
>
>
>2008/4/24, Vijay K. Gurbani
><<mailto:vkg at alcatel-lucent.com>vkg at alcatel-lucent.com>:
> > There is some work progressing in the BMWG WG to create performance
> > metrics around SIP. One of the first tasks in such an endeavor
> > is to define the notion of dialogs and sessions. Please see
> > Section 3.1.1 of
> >
> <https://svn.resiprocate.org/rep/ietf-drafts/gurbani/bmwg-sip-bench-term/draft-ietf-bmwg-sip-term-00.txt>https://svn.resiprocate.org/rep/ietf-drafts/gurbani/bmwg-sip-bench-term/draft-ietf-bmwg-sip-term-00.txt
> > of the above draft for some insight.
> >
> > �ï��¾ý wrote:
> >
> > > Hi, Lincoln
> > >
> > > thanks for your instructions.
> > >
> > > I know that dialog can exist without session since SUBSCRIBE/REFER can
> > > create dialog and without any media between communication peers.
> > >
> > > What I want to know is the relationship of dialog and session when
> > > they both exist in one communication activity. Take a example, when
> > > there are 2 person participating talks with voice, we say there is a
> > > dialog and a session.
> > >
> > > But when one caller invites another callee and gets five 200 final
> > > responses from 5 UA every of which has its own session description. We
> > > can say that there are 5 dialogs between caller and the other 5
> > > callees, right? And then what is the exact number of session in this
> > > scenario? One session or five session? That is what I want to know.
> > >
> > > Dialog is determined by dialogID (call-id, from/to tag) and session id
> > > is determined by session id given in the SDP message. My answer is
> > > there are 5 dialog and one session now, right?
> > >
> >
> > - vijay
> > --
> > Vijay K. Gurbani, Bell Laboratories, Alcatel-Lucent
> > 2701 Lucent Lane, Rm. 9F-546, Lisle, Illinois 60532 (USA)
> > Email:
> vkg at {<http://alcatel-lucent.com>alcatel-lucent.com,<http://bell-labs.com>bell-labs.com,<http://acm.org>acm.org}
> > WWW:
> <http://www.alcatel-lucent.com/bell-labs>http://www.alcatel-lucent.com/bell-labs
> >
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>
>--
>BR
>Donald
>_______________________________________________
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_______________________________________________
Sip mailing list https://www.ietf.org/mailman/listinfo/sip
This list is for NEW development of the core SIP Protocol
Use sip-implementors at cs.columbia.edu for questions on current sip
Use sipping at ietf.org for new developments on the application of sip