Subject: [SIP] Re: Status of SDPng

From: Joerg Ott <[email-masked]>
Date: Thu, 15 Jun 2000 09:24:07 +0200

Gonzalo,

the last available draft is draft-ott-mmusic-caps-01.txt which is currently
being heavily revised (note that the syntax section in the end is just giving
examaples).  At the moment we working on completing the modeling aspects
taking into account the various signaling protocols available (particularly
H.323 and SIP, also MEGACO to some degree) to provide a sufficiently rich yet
reasonably simple means for description that can satisfy the needs of all these
protocols.  We also consider local interaction between system components
(e.g. via the Mbus) for the modeling looking into how to model call,
conferences, applications (=media sessions), and individual media streams.
(this has to fit with SIP, SIP call control services, a future conference control
protocol, RTSP, and who knows what).  This model then needs to be linked to
the concrete syntax (a step that is entirely omitted in the old draft).

From a syntax point of view, we are yet undecided.  There is good reasoning to
stick close to the current SDP syntax to allow smooth introduction of new features
into implementations and retain backward compatibility.  And this is what we would
like to achieve given the increasing installed base of SDP.  Nevertheless, a little
more expressiveness for grouping, alternatives and the like would be nice to have.
There are ideas how you can do this without breaking SDP syntax but the semantics
typically changes with such extensions so that a new version numbers allowing for
new features does not seem unreasonable either.

We plan to publish the revised draft as basis for discussion by the end of June
or the beginning of July.

Of course, we welcome any input on all of this.

Joerg

>Hi,
>
>I would like to know the status of the so called, SDPng. Is there any
>draft available about it? Are there folks working on it? Time frame for
>this work, goals...
>
>Thanks,
>
>Gonzalo
>-- 
>Gonzalo Camarillo         Phone :  +358  9 299 33 71
>Oy L M Ericsson Ab        Mobile:  +358 40 702 35 35
>Telecom R&D               Fax   :  +358  9 299 30 52
>FIN-02420 Jorvas          Email :  [email-masked]
>Finland
> 

-------------------------------------------------------------------------------
Joerg Ott                                                  [email-masked]
Universitaet Bremen, Germany                              fax + 49 421 218-7000
Center for Computing Technology (TZI)                   voice + 49 421 201-7028
Digital Media and Networks                     http://www.tzi.uni-bremen.de/dmn

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