Re: [MMUSIC] Congestion control

Martin Thomson <martin.thomson@gmail.com> Mon, 10 June 2013 20:26 UTC

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Date: Mon, 10 Jun 2013 13:26:24 -0700
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From: Martin Thomson <martin.thomson@gmail.com>
To: Bernard Aboba <bernard_aboba@hotmail.com>
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Cc: "mmusic@ietf.org" <mmusic@ietf.org>, Cullen Jennings <fluffy@iii.ca>
Subject: Re: [MMUSIC] Congestion control
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On 10 June 2013 12:16, Bernard Aboba <bernard_aboba@hotmail.com> wrote:
> " No O/A is request to stop sending RTP packets on a given stream. "

With my Fluffy-filter on, I read that as saying: "No O/A is *required*
to stop sending RTP packets..."

> [BA]  So you're saying that you don't expect a=sendrecv/recvonly/sendonly to
> be used in Plan A to control streams described by individual m lines?    I
> had assumed that the O/A behavior described in RFC 3264 Sections 5.1 and 6.1
> would apply in Plan A.

I didn't infer anything like that.  I think that there is a distinct
difference between negotiating the possible existence of a stream and
requiring the existence of a stream.  When you use a=sendonly/etc...
you open the possibility of receiving the stream, which in most cases
will be fulfilled.  In a congestion scenario, the sender can (and
should) stop sending.

After all, the envelope established by SDP never excludes the
possibility that zero packets arrive.