Subject: Re: [AVT] Please review and comment on "in-band" RTP signaling methodology

From: [email-masked]
Date: Wed, 6 Mar 2002 10:55:54 -0600

AVT colleagues,

Please note that there is another proposal for "mode switching" that is
being considered by the TR-30.1 and ITU-T Q11/16 modem experts for use
with MoIP.

Perhaps it is premature for the IETF to consider SSE until the modem
experts are closer to deciding which method they would prefer? Or perhaps
the alternate method (known as the "reliable state update protocol", or
"RSUP") should also be run past the IETF?

If there is desire for the latter, I would be happy to submit the RSUP
proposal as an internet draft for IETF consideration. Because of timing,
it could not be discussed at an IETF meeting until Yokahama.

Comments expected and welcome.

Jim Renkel

Rajesh Kumar <[email-masked]>@ietf.org on 03/05/2002 05:58:50 PM

Sent by:  [email-masked]

To:   [email-masked]
cc:
Subject:  [AVT] Please review and comment on "in-band" RTP signaling
      methodology

AVT colleagues,

The draft
http://search.ietf.org/internet-drafts/draft-rajeshkumar-avt-sse-00.txt
describes an in-band signaling method that is being actively considered by
the TIA TR.30.1 and ITY SG16 groups. Since this is based on RTP, these
groups have considered it appropriate to review it in the IETF.

Please review and comment. We can request a slot for discussing issues at
the Minnesota or the Yokohama meetings, depending on the volume and nature
of the responses. Thanks,

Rajesh Kumar
Cisco Systems

_______________________________________________
Audio/Video Transport Working Group
[email-masked]
https://www1.ietf.org/mailman/listinfo/avt

_______________________________________________
Audio/Video Transport Working Group
[email-masked]
https://www1.ietf.org/mailman/listinfo/avt

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From: Rajesh Kumar <[email-masked]>
Date: Wed, 06 Mar 2002 10:18:00 -0800

AVT, TR-30.1, ITU Q11/16 colleagues,

>being considered by the TR-30.1 and ITU-T Q11/16 modem experts for use

Indeed, there is an alternate proposal from 3COM that is being actively 
considered. However, TR-30.1 and ITU-T Q11/16 are heavily leaning towards 
the SSE protocol in 
http://search.ietf.org/internet-drafts/draft-rajeshkumar-avt-sse-00.txt. To 
date, all of their call flows and protocol state machines use this 
protocol, which is the only mode switching protocol specified in any 
detail. The protocol state machine in this internet draft were crafted by 
the said study groups. My personal view is that the TR-30.1 and ITU-T 
Q11/16 will converge on the SSE protocol.

Having said that, the SSE protocol is by no means complete. TR-30.1 is 
working on defining the cause codes which will go into Section 6.4 of the 
next revision of the internet draft. Further, there has been no opportunity 
to review Jim Renkel's alternate proposal and compare it vis-a-vis SSEs as 
described in the referenced internet draft. All of this we hope to 
accomplish in time for the Yokohama meeting.

If I understand Colin's input to me correctly, it is never too premature to 
present "incomplete work" for consideration at the IETF. On the contrary, 
it would be wrong to ask the IETF to rubber-stamp a finished product that 
has been ratified elsewhere. This being so, I think it is perfectly fine to 
discuss issues pertaining the internet draft to the IETF AVT group, and to 
tap the better RTP expertise present in this working group.

Jim, why don't you kick of the AVT discussion in mode switching issues by 
circulating your objections to the SSE internet draft, and how you intend 
to resolve them in your RSUP proposal? To be perfectly honest, I have not 
seen your counter-proposal, but I would love to take a look at it if it is 
available so that we can use the best of everything available to use.

Colin, I perfectly understand (and agree with)  your note re: collecting 
and discussing pertinent issues in this working group. I am going to do 
precisely that. I am inclined to think that we should postpone the 
face-to-face discussion of these issues until Yokohoma, until the TR-30.1 
and ITU Q11/16 have has a change to fill in the incomplete section (to wit, 
cause codes) in the internet draft, and until Jim Renkel has had a chance 
to put together the 3COM counterproposal. Meanwhile, we can utilize the 
IETF AVT forum to garner and process inputs from a wider group than that 
which participates actively in the TR-30.1 and ITU Q11/16 working sessions.

Thanks,

Rajesh Kumar
Cisco Systems

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From: Colin Perkins <[email-masked]>
Date: Fri, 08 Mar 2002 15:47:33 -0500

Rajesh,

It seems that there are a number of open issues, and several proposals, and
it would be valuable to discuss these in the AVT meeting in Minneapolis. We
have scheduled time in the meeting for discussion.

Colin