Subject: Multiple streams per call,

From: Thomas LEVY <[email-masked]>
Date: Thu, 13 Apr 2000 10:18:32 +0200

Hi,

Megaco supports multiple media streams per termination => so 1 call (or
conference) with multiple streams may corresponds to 1 context viewed
from a media gateway.
The reciprocal is not so clear to me: MUST all the media streams from 1
call be associated to 1 context.
In other term, is there a "one for one" relationship between Context and
Call?
In fact, I think no.
I was thinking about a case where terminal A and terminal B are trying
to establish an Audio/Video (with separate streams) call. But as audio
encoding supported by A and B are compatible, video encoding are not
compatible thus requiring the transcoding function of the media gateway
MG1. In such case, I think that the MGC should control the audio stream
in order to go from A to B directly, while video stream go from A to B
via MG1.
Does it seem to you to be a scenario in the scope of Megaco?
Comments welcome,

Thomas LEVY,
Alcatel Corporate Research Center

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From: Chip Sharp <[email-masked]>
Date: Thu, 13 Apr 2000 09:50:12 -0400

>call be associated to 1 context.

I believe the answer is yes.

>In other term, is there a "one for one" relationship between Context and

Since "call" isn't so well defined, this isn't so clear.

>Does it seem to you to be a scenario in the scope of Megaco?

In order to do this, I believe you would have to add multiple terminations
to the context (from A's perspective, one for MG1 and one for B) and fiddle
with the topology parameter to get things to go to the correct place.  But
I'm not sure.  Since one of the primary design criteria for H.248 was to
support multimedia calls easier, I'm sure someone will answer with a simple
way to do this.

>Alcatel Corporate Research Center

http://www.netaid.org
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Chip Sharp                 CTO Consulting Engineering
Cisco Systems
Reality - Love it or Leave it.
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