Subject: [SIPPING] question on draft-johnston-sipping-cc-conferencing-00.txt

From: Michael Hammer <[email-masked]>
Date: Tue, 05 Nov 2002 12:35:14 -0500

In this draft the creating of a new conference and the joining of an 
existing conference appear identical.  Given that conference servers may 
host many conferences, and given that collision of selected identifiers 
could occur, is there any way for a user to indicate that they wish to 
connect to an existing conference versus creating a new one?

A value such as "isnew" or "existing" could also permit, in the first case, 
an error indicating that a conference by that name already exists, or in 
the second case, an error indicating that a conference by that name does 
not exist.

The presumption is that you do not want to interrupt an existing conference 
already in progress (case 1) or you do not want to create a conference (and 
pay corresponding charges) as an invitee if the invitor is not present 
(case 2).

Is such a protection covered elsewhere in another draft?

Mike

_______________________________________________
Sipping mailing list  https://www1.ietf.org/mailman/listinfo/sipping
This list is for NEW development of the application of SIP
Use [email-masked] for questions on current sip
Use [email-masked] for new developments of core SIP

---

From: Jonathan Rosenberg <[email-masked]>
Date: Tue, 05 Nov 2002 15:40:45 -0500

> connect to an existing conference versus creating a new one?

The draft proposes two separate URIs for creating a new conference, and 
joining an existing one. Therefore, a UA would indicate which case they 
desire by using the appropriate URI. THis presumes that there is some 
other means for propagatign those URIs. I believe the genreal model is 
that the "Conference factory URI" - used for creating conferences - 
would be learned through configuration. THe conference URI itself would 
be handed out as a result of sending an INVITE to the conference factory 
URI. You could also get one through email, IM, web links, etc., in which 
case the context is provided to the user - "click here to JOIN the 
conference".

> 
> A value such as "isnew" or "existing" could also permit, in the first 
> case, an error indicating that a conference by that name already exists, 
> or in the second case, an error indicating that a conference by that 
> name does not exist.

In the case of creation, the client does not provide the conference URI, 
it is given the conference URI by the server. So, there can never be 
collisions. In terms of trying to join a conference that doesnt exist - 
well, we have an error for that. Its 404 (Not Found).

> 
> The presumption is that you do not want to interrupt an existing 
> conference already in progress (case 1) or you do not want to create a 
> conference (and pay corresponding charges) as an invitee if the invitor 
> is not present (case 2).
> 

I dont think its needed. As above, the intent is encoded in the URI 
which is used...

-Jonathan R.

-- 
Jonathan D. Rosenberg, Ph.D.                72 Eagle Rock Ave.
Chief Scientist                             First Floor
dynamicsoft                                 East Hanover, NJ 07936
[email-masked]                     FAX:   (973) 952-5050
http://www.jdrosen.net                      PHONE: (973) 952-5000
http://www.dynamicsoft.com

---

From: Michael Hammer <[email-masked]>
Date: Tue, 05 Nov 2002 16:16:07 -0500

Jonathan,

Perhaps, I am misreading this or being mislead by the diagrams.  In Figure 
2, Alice is creating the conference, and in Figure 3, Carol is joining a 
conference in progress.  My understanding is that the value represented by 
"Conf-ID" is identical in these two figures.  Could you explain to me where 
the difference lies?

Mike

Figure 2:

      Alice                Focus                 Bob                Carol
        |                    |                    |                    |
        | Alice creates the conference and chooses the conference URI. 
|
        |                    |                    |                    |
        | INVITE sip:Conf-ID F1                   |                    |
        |------------------->|                    |                    |
        |   180 Ringing F2   |                    |                    |
        |<-------------------|                    |                    |
        |   200 OK Contact:Conf-ID;isFocus F3     |                    |
        |<-------------------|                    |                    |
        |        ACK F4      |                    |                    |
        |------------------->|                    |                    |

Figure 3:

      Alice                Focus                 Bob                Carol
        |                    |                                         |
        |<==================>|                                         |
        |                    |    Carol "dials in" to the conference   |
        |                    |                                         |
        |                    |              INVITE sip:Conf-ID F1      |
        |                    |<----------------------------------------|
        |                    |               180 Ringing F2            |
        |                    |---------------------------------------->| 

        |                    |     200 OK Contact:Conf-ID;isFocus 
F3   |
        |                    |---------------------------------------->| 

        |                    |                   ACK F4                |
        |                    |<----------------------------------------| 

At 03:40 PM 11/5/2002 -0500, Jonathan Rosenberg wrote:

>that the "Conference factory URI" - used for creating conferences - would 
>be learned through configuration. THe conference URI itself would be 
>handed out as a result of sending an INVITE to the conference factory URI. 
>You could also get one through email, IM, web links, etc., in which case 
>the context is provided to the user - "click here to JOIN the conference".
>
>
>>or in the second case, an error indicating that a conference by that name 
>>does not exist.
>
>I dont think its needed. As above, the intent is encoded in the URI which 
>is used...
>
>-Jonathan R.
>
>--