Subject: RE: [Sipping] Transcoding/Reconciling Device Capabilities

From: "Roy, Radhika" <[email-masked]>
Date: Wed, 16 Feb 2005 12:51:15 -0500

Hi, Gonzalo and Henry:

I find that the following drafts of yours have some similarities so far
transcoding is concerned. I find that Henning's draft addresses more
generic way including mobility.

http://www.ietf.org/internet-drafts/draft-shacham-sipping-session-mobili
ty-00.txt

http://standards.ericsson.net/gonzalo/papers/draft-ietf-sipping-transc-f
ramework-00.txt

http://www.ietf.org/internet-drafts/draft-ietf-sipping-transc-3pcc-02.tx
t

http://standards.ericsson.net/gonzalo/papers/draft-camarillo-sipping-tra
nsc-b2bua-01.txt

Let me suggest that all transcoding drafts be extended to make them more
generic, as Henning has done in Section 6 of his draft, titling as
"Reconciling Device Capability Differences" and use codec differences,
TTS, STT, bandwidth differences, QoS parameter differences, etc. as
separate examples.

Is this suggestion acceptable?

Best regards,
Radhika

PS: BTW - I appreciate Henning's session mobility draft. It is a
pre-cursor of real-time multimedia communications in Ad Hoc (MANET)
Networking environments.

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From: Gonzalo Camarillo <[email-masked]>
Date: Tue, 22 Feb 2005 11:30:16 +0200

Hi Roy,

inline:

> Hi, Gonzalo and Henry:

I guess you meant "Henning", right?

> generic way including mobility.

Henning's draft deals with transcoding by using the 3pcc model 
documented in the 3pcc transcoding draft. There isn't any inconsistency 
as far as I can see between both drafts.

Of course, Henning's draft covers ground that is outside the scope of 
the transcoding work.

> Is this suggestion acceptable?

The transcoding drafts already state that the mechanisms described there 
are general and can be used to invoke simple transcoders or more 
complicated media servers. From the Introduction of the transcoding 
framework:

    So,
    the invocation mechanisms described in this document are generally
    applicable to any type of incompatibility related to how the
    information that needs to be communicated is encoded.

         Furthermore, although this framework focuses on
         transcoding, the mechanisms described are applicable to
         media manipulation in general. It would be possible to use
         them, for example, to invoke a server that simply increased
         the volume of an audio stream.

In any event, in future revisions of this document we will try to stress 
(even more) this point, as you suggest.

Thanks for the comments,

Gonzalo