Re: [rtcweb] Fwd: I-D Action: draft-alvestrand-one-rtp-00.txt

"Muthu Arul Mozhi Perumal (mperumal)" <mperumal@cisco.com> Fri, 12 August 2011 13:09 UTC

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From: "Muthu Arul Mozhi Perumal (mperumal)" <mperumal@cisco.com>
To: Harald Alvestrand <harald@alvestrand.no>, rtcweb@ietf.org
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Subject: Re: [rtcweb] Fwd: I-D Action: draft-alvestrand-one-rtp-00.txt
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A few comments:
 
1) Section 4 has this:
If the responder understands the semantics of the TOGETHER extension,
the parameters of the first section MUST be used to establish the RTP
session, and the parameters for the other sections MUST be ignored.
 
I think it needs to be:
If the responder understands the semantics of the TOGETHER extension,
the parameters of the first section MUST be used to establish the RTP
and RCP session, and the parameters for the other sections MUST be 
ignored.
 
2) When the RTCP port is not the next higher (odd) port number following
the RTP port described in the m-line, the "a=rtcp" attribute (defined in
RFC-3605) is used to signal it, as in:
m=audio 49170 RTP/AVP 0
a=rtcp:53020 IN IP4 126.16.64.4
 
With the grouping semantics described in the draft, it seems this RTCP
port should be taken only from the first section. So, this could be
could be added to section 4.
 
3) RTCP could be multiplexed with RTP on a single port and signaled
using the "a=rtcp-mux" attribute (defined in RFC 5761). When it is used
together with the grouping semantics described in the draft, it seems
all RTCP sessions of that group need to be multiplexed on the RTP port
from the first section.
 
Muthu
 
From: rtcweb-bounces@ietf.org [mailto:rtcweb-bounces@ietf.org] On Behalf
Of Harald Alvestrand
Sent: Thursday, August 11, 2011 5:02 PM
To: rtcweb@ietf.org
Subject: [rtcweb] Fwd: I-D Action: draft-alvestrand-one-rtp-00.txt
 
I have taken some of the information I learned from the discussions in
Quebec City about the issues of putting video and audio into the same
RTP session and created a draft from them outlining a solution to the
problem of signalling this configuration using SDP.

Comments welcome, including the recommended context for processing the
document; in a few days I'll send the same note to AVTCORE and/or
MMUSIC.

                      Harald

-------- Original Message -------- 
Subject: 
I-D Action: draft-alvestrand-one-rtp-00.txt
Date: 
Thu, 11 Aug 2011 04:28:09 -0700
From: 
internet-drafts@ietf.org
Reply-To: 
internet-drafts@ietf.org
To: 
i-d-announce@ietf.org
 
A New Internet-Draft is available from the on-line Internet-Drafts
directories.
 
       Title           : SDP Grouping for Single RTP Sessions
       Author(s)       : Harald Tveit Alvestrand
       Filename        : draft-alvestrand-one-rtp-00.txt
       Pages           : 8
       Date            : 2011-08-11
 
   This document describes an extension to the Session Description
   Protocol (SDP) to describe RTP sessions where media of multiple top
   level types, for example audio and video, are carried in the same RTP
   session.
 
   This document is presented to the RTCWEB, AVTCORE and MMUSIC WGs for
   consideration.
 
 
 
A URL for this Internet-Draft is:
http://www.ietf.org/internet-drafts/draft-alvestrand-one-rtp-00.txt
 
Internet-Drafts are also available by anonymous FTP at:
ftp://ftp.ietf.org/internet-drafts/
 
This Internet-Draft can be retrieved at:
ftp://ftp.ietf.org/internet-drafts/draft-alvestrand-one-rtp-00.txt
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