Subject: RE: [AVT] [Fwd: I-D ACTION:draft-wenger-avt-avpf-ccm-02.txt]

From: "Desineni, Harikishan" <[email-masked]>
Date: Mon, 20 Feb 2006 13:04:41 -0800

Two comments on Section
4.2.2.1

[A]
"The "SSRC of the packet sender" field indicates the source of the
   notification.  The "SSRC of media source" SHALL be set to the SSRC of
   the media sender that currently owns the bit-rate limitation"

I think the it should stated as (replace the sender with receiver in the
Last line)

"The "SSRC of the packet sender" field indicates the source of the
   notification.  The "SSRC of media source" SHALL be set to the SSRC of
   the media receiver that currently owns the bit-rate limitation"

[B] 

If the current "owner" leaves the session, the session may benefit
if a sender re-computes the low bit rate limit and assigns a new owner.
Not doing so may leave a sender continue to operate at low bit-rate,
impacting the quality experienced by rest of the session members.
This also means that a sender MAY generate TMMBN anytime.

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf Of
Magnus Westerlund
Sent: Wednesday, February 15, 2006 2:09 AM
To: IETF AVT WG
Subject: [AVT] [Fwd: I-D ACTION:draft-wenger-avt-avpf-ccm-02.txt]

Hi,

The updated version of the codec control messages is now available. The 
main changes are:

- Revised topology section. With discussion on how the commonly used 
models relate to the by RTP translator and mixer concepts.
- Updated solution for TMMBR not requiring request ACKs, instead 
notification messages are used that suppress further requests from other

participants.

Please provide feedback

Cheers

Magnus Westerlund

Multimedia Technologies, Ericsson Research EAB/TVA/A
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From: Magnus Westerlund <[email-masked]>
Date: Tue, 21 Feb 2006 09:35:14 +0100

>    the media receiver that currently owns the bit-rate limitation"

Yes, you are correct. We will fix this.

> This also means that a sender MAY generate TMMBN anytime.

The intention of this author was that if a media receiver currently 
owning a limitation times out, that that limitation goes away. Which 
should trigger a TMMBN message sending. I see that I missed putting 
these things in.

The difference with your proposal is that the media sender does not need 
to keep state for other requests. Secondly the media receivers that have 
seen the ownership being transfered to someone else does also not need 
to keep state. A potential downside of this is that the bit-rate becomes 
unrestricted until another media receiver manages to establish a new limit.

Thanks for the comments.

Cheers

Magnus Westerlund