Subject: RE: [MMUSIC] video media control draft

From: Orit Levin <[email-masked]>
Date: Wed, 24 Jul 2002 18:12:04 -0400

I have been thinking that this is the simplest one :-)

Of cause, the Encoder MUST be able to ignore any request... because it MUST
comply to whatever "prevent congestion algorithms" it supports. It doesn't
contradict the fact that the higher application MUST be able to request
whatever it needs to (... and be capable to get rejected by the lower
layer).

These are different decision layers. Both exist in any valid application.

The point here is that the resultant behavior of the low layer would be
DIFFERENT between the too cases! Only in one of the cases (out of the two)
the FIR is also a symptom of congestion condition in the network - the input
that would be taken into account while performing the local "prevent
congestion algorithm".

Cheers,

Orit Levin
Chief Architect
RADVISION Inc.
Tel:  +1.201.689.6330

>As for the RTCP feedback, the AVT group did not agree on requests but on an
>indication that will still allow the encoder to ignore the message. As can
>be seen from 4.3.2 above the request for full picture will not cause
>congestion even in H.320 sine the encoder may reduce quality of the full
>picture.

This is the core point of disagreement, I believe. I would argue that, no
matter how the fast update request message is transmitted, the encoder MUST
be able to ignore the request (because, for example, there may be IP level
congestion). The fact that the encoder can reduce quality so that the bit-
rate does not increase due to the full intra picture is irrelevent, since
it is possible that the network will have insufficient capacity for that
rate too.

Colin

_______________________________________________
mmusic mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/mmusic

---

From: Colin Perkins <[email-masked]>
Date: Wed, 24 Jul 2002 18:28:51 -0400

>These are different decision layers. Both exist in any valid application.

Yes, of course, that's what I've been saying all along. My complaint was
with the statement in the message I replied to, which said that this was
not acceptable behaviour.

>that would be taken into account while performing the local "prevent

Yes, agreed.
Colin