Re: [MMUSIC] BUNDLE: no reason por payload type to be unique within bundled m= lines

Iñaki Baz Castillo <ibc@aliax.net> Thu, 17 March 2016 09:38 UTC

Return-Path: <ibc@aliax.net>
X-Original-To: mmusic@ietfa.amsl.com
Delivered-To: mmusic@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 263AF12D5E9 for <mmusic@ietfa.amsl.com>; Thu, 17 Mar 2016 02:38:45 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.6
X-Spam-Level:
X-Spam-Status: No, score=-2.6 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, RCVD_IN_DNSWL_LOW=-0.7] autolearn=unavailable autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=aliax-net.20150623.gappssmtp.com
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id xHHKes7-T8CJ for <mmusic@ietfa.amsl.com>; Thu, 17 Mar 2016 02:38:45 -0700 (PDT)
Received: from mail-yw0-x232.google.com (mail-yw0-x232.google.com [IPv6:2607:f8b0:4002:c05::232]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 10A5312D5AA for <mmusic@ietf.org>; Thu, 17 Mar 2016 02:30:51 -0700 (PDT)
Received: by mail-yw0-x232.google.com with SMTP id g127so92874226ywf.2 for <mmusic@ietf.org>; Thu, 17 Mar 2016 02:30:50 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=aliax-net.20150623.gappssmtp.com; s=20150623; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=GTiiAWCSRrCv4IgOZcu+znHtretVAosbZLX53/YCDgc=; b=Z8kfn4bKjHRuTzxkKGbldqUKGSMgT7MKRfVmyTQpyb40Oe4SYd1g6Vf/gbQZsN1h1G c11fL/VkBqIU38sWYLf8y6LSTZgngL1SdjDUbJOa8GAUb/ICBm7GNj6R+TxplyGnrlsz 0y1yn32x7wGm5vyFU6iEVlQbc1d0VpGEFMneu5M+FduEmInopEhDhIXtw4JEDPawQlVO yzH64R5A/C/j/25S5aGoNj0wQyiLC9H8GnI8eNidCVabzeD6DV0duxPLUZwPuCAHcYBl RZ0PIVIFBSSOSLocJEnDMmGelhPrLZ8CJ8P1YJNxBjY+UgIcoTXvZaOO6izpDLW6tfj6 yIPA==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=GTiiAWCSRrCv4IgOZcu+znHtretVAosbZLX53/YCDgc=; b=QnjnOtFtZ7qHskcb+cuViGTytDO9JCy4ay1taYcbxnQBpqjgeqFsmftoR915CnK3wD vojQpadWtjCaRbHXDpHVhFcbeQxdT9XPe2waqjXVlsA20BjtLdK1cPxtv0nVvwCdValc ukn5yTJa8a329q+7fk8QGFRU4tH1bDWcZUIEs1OIjGXE20XTdX5iNEwIRoS+FvwYfZg0 ELQqnz+WtZsijOLXsQS7rM6MAxdN7zJounR/TR3CefSb3SahCclGLkVd6FW+Um6fNYub OOZoIxfgB9+pEVaCbDjp8Xsn7wmqhwT1YdFvbl8jor+Vq7K9M6j3nTZKarPcQbm9UF3d SLiw==
X-Gm-Message-State: AD7BkJItXiHMeyHtTRxpb6Ddl+ZcKyrYI7dPwhHZJ8xSP9SBQbg2wbQ8/jSsAJq85QpUhhclT1uaxob+UAToWw==
X-Received: by 10.37.231.8 with SMTP id e8mr3553633ybh.144.1458207050177; Thu, 17 Mar 2016 02:30:50 -0700 (PDT)
MIME-Version: 1.0
Received: by 10.37.201.132 with HTTP; Thu, 17 Mar 2016 02:30:30 -0700 (PDT)
In-Reply-To: <D3103E3F.5BBE%christer.holmberg@ericsson.com>
References: <CALiegfm7Rb4e5DFGycr=EsdigE1XFCUiqNL6+GpRSyrGe=_RWg@mail.gmail.com> <56DED735.1000101@ericsson.com> <CALiegf=G77JOcoR6DORnPsMx4OCgy=_dYQ_r8KfjMy_33vn89A@mail.gmail.com> <7594FB04B1934943A5C02806D1A2204B37E9EA74@ESESSMB209.ericsson.se> <CALiegf=F4z9r+oCO1DMW_nXq7TBJjf-n3N1r6yr5tLoksXtUqg@mail.gmail.com> <7594FB04B1934943A5C02806D1A2204B37E9FDAB@ESESSMB209.ericsson.se> <CALiegf=kzThQ3n+Z-=E8G=ivyL1W=Q4gUcQenihAJ3pmv8udKQ@mail.gmail.com> <7594FB04B1934943A5C02806D1A2204B37EA257B@ESESSMB209.ericsson.se> <CALiegfnLMUZnA=AQEnvFhxKKbwUeg=sFHRiC9R2MxisY-43UFg@mail.gmail.com> <D31037D8.5B90%christer.holmberg@ericsson.com> <CALiegfmWPrai9a1hkj5rpLeyowspAcpr3jNZpNyc4HatXGfo9Q@mail.gmail.com> <D3103E3F.5BBE%christer.holmberg@ericsson.com>
From: Iñaki Baz Castillo <ibc@aliax.net>
Date: Thu, 17 Mar 2016 10:30:30 +0100
Message-ID: <CALiegfmzO_1nuQmE3SYJk-OtYZ2GHzjfTzkgJ=1zwoRcD+NmCw@mail.gmail.com>
To: Christer Holmberg <christer.holmberg@ericsson.com>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Archived-At: <http://mailarchive.ietf.org/arch/msg/mmusic/wErkSMxToPcVDQ9HNsTMn3xwYTM>
Cc: Magnus Westerlund <magnus.westerlund@ericsson.com>, "mmusic@ietf.org" <mmusic@ietf.org>
Subject: Re: [MMUSIC] BUNDLE: no reason por payload type to be unique within bundled m= lines
X-BeenThere: mmusic@ietf.org
X-Mailman-Version: 2.1.17
Precedence: list
List-Id: Multiparty Multimedia Session Control Working Group <mmusic.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/mmusic>, <mailto:mmusic-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/mmusic/>
List-Post: <mailto:mmusic@ietf.org>
List-Help: <mailto:mmusic-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/mmusic>, <mailto:mmusic-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 17 Mar 2016 09:38:46 -0000

2016-03-17 10:09 GMT+01:00 Christer Holmberg <christer.holmberg@ericsson.com>:
>>I just hope that BUNDLE is a required step in order to separate each
>>RTP "sender" and RTP "receiver" within a RTP session, so in the future
>>we can get rid of SDP and design a proper RTP parameters based API for
>>WebRTC.
>
>
> That is not the purpose of BUNDLE. The purpose is to be able to negotiate
> multiplexed media on a single RTP session

- "RTP session" == stuff carried over a single transport (let's assume
rtcp-mux always).

- "media" == audio / video / data, which can be sent and/or received.

So yes, BUNDLE somehow allows defining each RTP sender and/or receiver
in a separate m= section.


> If we want to change the rule saying that PT values must be unique per
> codec/codec configuration, I think that¹s a separate task.

We can't do that because there are a lot of legacy and very expensive
RTP middleboxes made in 20th century that miraculously are suitable
for WebRTC even if they don't even know what a SSRC is. And they must
work without any code update!


-- 
Iñaki Baz Castillo
<ibc@aliax.net>