Re: [AVTCORE] Multi-party real-time text requiring new RTP payload type

xthe.various.worley@ariadne.com Wed, 06 May 2020 02:41 UTC

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From: xthe.various.worley@ariadne.com (Dale R. Worley)
To: Gunnar =?utf-8?Q?Hellstr=C3=B6m?= <gunnar.hellstrom@ghaccess.se>
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Date: Tue, 05 May 2020 22:40:51 -0400
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Subject: Re: [AVTCORE] Multi-party real-time text requiring new RTP payload type
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Gunnar Hellstr\"om <gunnar.hellstrom@ghaccess.se> writes:
> I propose to add the following last in the introduction:
>
> -------
>
> 1.1.  Considered alternative
>
>     The mechanism specified in the present document makes use of the RTP
>     mixer model specified in [RFC3550].  From some points of view, use of
>     the RTP translator model specified in RFC 3550 would be more
>     efficient, because the text packets can pass the translator with only
>     minor modification.  However, there is no widely supported sdp
>     [RFC4566] specification for the translator model.

It doesn't seem to be that lack of an SDP specification for a
translatory would be needed, but I suspect that's due to my lack of
knowledge of the practical problems involved -- as far as I can tell,
such a connection could be negotiated in the ordinary way, and the fact
that the packets' SSRCs vary would identify that there were various
sources interleaved.

Though given that some protocol action will be necessary anyway (e.g.,
defining a new payload type), would it be difficult to invent an SDP
attribute that means "multiple sources will be interleaved, check the
SSRCs"?

Dale