Re: [rtcweb] draft-alvestrand-one-rtp-00.txt and profile

Harald Alvestrand <harald@alvestrand.no> Mon, 15 August 2011 08:32 UTC

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Date: Mon, 15 Aug 2011 10:33:38 +0200
From: Harald Alvestrand <harald@alvestrand.no>
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To: Christer Holmberg <christer.holmberg@ericsson.com>
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Cc: "rtcweb@ietf.org" <rtcweb@ietf.org>
Subject: Re: [rtcweb] draft-alvestrand-one-rtp-00.txt and profile
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On 08/15/11 09:57, Christer Holmberg wrote:
> Hi,
> There are discussions in other SDOs about using AVPF for video and AVP 
> for audio, within a session.
> However, those discussions are not within the context of multiplex.
I added the following text:

The reason for the requirement for systematic proto is that there are 
many combinations that don't make sense (for instance "RTP/AVPF" in one 
section and "RTP/SAVP" in another would make encryption and availability 
of TMMBR depend on the outcome of negotiation, which seems strange). The 
cases where combinations make sense (RTP/AVPF with UDP/FEC for instance) 
also usually require that separate RTP sessions be used. [[QUESTION IN 
DRAFT: Are there sensible combinations?]]

Makes sense?
> Regards,
> Christer
>
>     ------------------------------------------------------------------------
>     *From:* Harald Alvestrand [mailto:harald@alvestrand.no]
>     *Sent:* 14. elokuuta 2011 23:15
>     *To:* Christer Holmberg; rtcweb@ietf.org
>     *Subject:* RE: draft-alvestrand-one-rtp-00.txt and profile
>
>     The profile affects the protocols available (such as tmmbr, or
>     whether it is rtp or something completely different. Some
>     parameters may be meaningless under a different profile. So making
>     profile dependent on TOGETHER support looked strange to me. Do you
>     see any case where different profiles would be critical?
>     -- 
>     Sent from my Android phone with K-9 Mail. Please excuse my brevity.
>
>     Christer Holmberg <christer.holmberg@ericsson.com> wrote:
>
>         Hi Harald,
>
>         Section 3 of the draft says that the profile of the sections MUST be the same, but there is no justification.
>
>         Could you please explain the reason behind that MUST?
>
>         Regards,
>
>         Christer
>
>