Re: [AVT] Fwd: I-D Action:draft-perkins-avt-rapid-rtp-sync-02.txt

Thomas Schierl <schierl@hhi.fhg.de> Fri, 06 March 2009 16:42 UTC

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Date: Fri, 06 Mar 2009 17:42:39 +0100
From: Thomas Schierl <schierl@hhi.fhg.de>
Organization: Fraunhofer HHI
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Cc: Colin Perkins <csp@csperkins.org>
Subject: Re: [AVT] Fwd: I-D Action:draft-perkins-avt-rapid-rtp-sync-02.txt
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Dear All,

As we already got a few comments, I would like to pick out the following 
one raised by Roni:

Might there be a security issue if an NTP timestamp is contained in the 
header extension in plain and is at the same time included in the 
encrypted portion of an RTCP SR packet?

Thomas


-- 
Thomas Schierl
--------------
Fraunhofer HHI


Colin Perkins wrote:
> This draft is a merger between draft-perkins-avt-rapid-rtp-sync-01.txt 
> and draft-schierl-avt-rtp-ntp-for-layered-codecs-00.txt.
>
> Please send any comments to the list. We'd like this to be considered 
> for adoption as an AVT working group draft.
>
> Colin
>
>
>
> Begin forwarded message:
>> From: Internet-Drafts@ietf.org
>> Date: 13 February 2009 14:45:01 GMT
>> To: i-d-announce@ietf.org
>> Subject: I-D Action:draft-perkins-avt-rapid-rtp-sync-02.txt
>> Reply-To: internet-drafts@ietf.org
>>
>> A New Internet-Draft is available from the on-line Internet-Drafts 
>> directories.
>>
>>     Title           : Rapid Synchronisation of RTP Flows
>>     Author(s)       : C. Perkins, T. Schierl
>>     Filename        : draft-perkins-avt-rapid-rtp-sync-02.txt
>>     Pages           : 18
>>     Date            : 2009-02-13
>>
>> This memo outlines how RTP multimedia sessions are synchronised, and
>> discusses how rapidly such synchronisation can occur.  We show that
>> most RTP sessions can be synchronised immediately, but that the use
>> of video switching multipoint conference units (MCUs) or large source
>> specific multicast (SSM) groups can greatly increase the initial
>> synchronisation delay.  This increase in delay can be unacceptable to
>> some applications that use layered and/or multi-description codecs.
>>
>> This memo updates the RTP Control Protocol (RTCP) timing rules to
>> reduce the initial synchronisation delay for SSM sessions.  A new
>> feedback packet is defined for use with the Extended RTP Profile for
>> RTCP-based Feedback (RTP/AVPF), allowing video switching MCUs to
>> rapidly request resynchronisation.  Two new RTP header extensions are
>> defined to allow rapid synchronisation of late joiners, and guarantee
>> correct timestamp based decoding order recovery for layered codecs in
>> the presence of clock skew.
>>
>> A URL for this Internet-Draft is:
>> http://www.ietf.org/internet-drafts/draft-perkins-avt-rapid-rtp-sync-02.txt 
>>
>
>
>




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[AVT] Fwd: I-D Action:draft-perkins-avt-rapid-rtp… Colin Perkins
Re: [AVT] I-D Action:draft-perkins-avt-rapid-rtp-… Ingemar Johansson S
Re: [AVT] Fwd: I-D Action:draft-perkins-avt-rapid… gerard.babonneau
Re: [AVT] Fwd: I-D Action:draft-perkins-avt-rapid… Thomas Schierl
Re: [AVT] Fwd: I-D Action:draft-perkins-avt-rapid… Colin Perkins