[MMUSIC] Fwd: SDP review of draft-ietf-avtext-rtp-stream-pause-07

Paul Kyzivat <pkyzivat@alum.mit.edu> Wed, 10 June 2015 18:21 UTC

Return-Path: <pkyzivat@alum.mit.edu>
X-Original-To: mmusic@ietfa.amsl.com
Delivered-To: mmusic@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 8C7541B2ED5 for <mmusic@ietfa.amsl.com>; Wed, 10 Jun 2015 11:21:08 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.235
X-Spam-Level:
X-Spam-Status: No, score=-1.235 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, SPF_SOFTFAIL=0.665] autolearn=no
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 xehjm1_QF3en for <mmusic@ietfa.amsl.com>; Wed, 10 Jun 2015 11:21:07 -0700 (PDT)
Received: from resqmta-ch2-07v.sys.comcast.net (resqmta-ch2-07v.sys.comcast.net [IPv6:2001:558:fe21:29:69:252:207:39]) (using TLSv1.2 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 412791B2E26 for <mmusic@ietf.org>; Wed, 10 Jun 2015 11:21:07 -0700 (PDT)
Received: from resomta-ch2-05v.sys.comcast.net ([69.252.207.101]) by resqmta-ch2-07v.sys.comcast.net with comcast id eiJH1q0072Bo0NV01iM6wo; Wed, 10 Jun 2015 18:21:06 +0000
Received: from Paul-Kyzivats-MacBook-Pro.local ([50.138.229.151]) by resomta-ch2-05v.sys.comcast.net with comcast id eiM51q00h3Ge9ey01iM634; Wed, 10 Jun 2015 18:21:06 +0000
Message-ID: <55788010.8030102@alum.mit.edu>
Date: Wed, 10 Jun 2015 14:21:04 -0400
From: Paul Kyzivat <pkyzivat@alum.mit.edu>
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:31.0) Gecko/20100101 Thunderbird/31.7.0
MIME-Version: 1.0
To: IETF MMUSIC WG <mmusic@ietf.org>
References: <557870CB.9090800@alum.mit.edu>
In-Reply-To: <557870CB.9090800@alum.mit.edu>
Content-Type: text/plain; charset="utf-8"; format="flowed"
Content-Transfer-Encoding: 7bit
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=comcast.net; s=q20140121; t=1433960466; bh=FgledGN7ilcDOnVEVJOle3DFSkiBZRfQhynUK9r8P5U=; h=Received:Received:Message-ID:Date:From:MIME-Version:To:Subject: Content-Type; b=hnK8HsdDpVH4t6g+desNfKoe9gHuytsJgrUwML1Gn1Be5dfhfSbWm8GfIBBq2Y6rP Key6A3u/D4elrR2x6tZ0ttV/xKHqcqVGV9tAN5IuFFX+wnJY4FxjxDrCXe1haU+tY/ SHYYlItsW78a6jpb5lkb5JFvvQRG5YpBmXaLnaGP7AxiSQzw/GBpwkDxIPCsOyDJK5 SRdO0Sai/8hmc3Hl/vmVBEWDnBXEOhKBYwI+pbSgeetMBjWzfknODlJ5pyOXv6UHPt LKO9tlCcL1pohBVfT/dAdidUDaIKWSlXoR5NAdew2uo+zzwfBp5L1HbG3sYuJxWBNc gTu4xY92QmUZg==
Archived-At: <http://mailarchive.ietf.org/arch/msg/mmusic/RNmyUr0iABuQzVNvtkrERIvIg3M>
Subject: [MMUSIC] Fwd: SDP review of draft-ietf-avtext-rtp-stream-pause-07
X-BeenThere: mmusic@ietf.org
X-Mailman-Version: 2.1.15
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: <http://www.ietf.org/mail-archive/web/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: Wed, 10 Jun 2015 18:21:08 -0000

FYI

-------- Forwarded Message --------
Subject: SDP review of draft-ietf-avtext-rtp-stream-pause-07
Date: Wed, 10 Jun 2015 13:15:55 -0400
From: Paul Kyzivat <pkyzivat@alum.mit.edu>
To: draft-ietf-avtext-rtp-stream-pause.all@ietf.org, avtext@ietf.org
CC: SDP Directorate <sdp-directorate-private@ietf.org>

I am the assigned SDP directorate reviewer for this draft.
For background on the SDP directorate, please see the FAQ at
http://www.ietf.org/iesg/directorate/sdp.html

Please wait for direction from your document shepherd or AD before
posting a new version of the draft.

Summary:

The SDP aspects of this draft are well written and clear. In my opinion
it *can* be published in this form.

However, I do have concern about one aspect - that the manner of
configuring the supported options of this feature is obscure and
confusing. (This is of course a matter of taste.)

Details:

I have concerns about the way the configuration of options is specified
using a numeric value. I can see how that might be reasonable if the
numbers represented a pure hierarchy. But that seems not to be the case.
The rules for valid answers are quite complex. (It isn't something that
can be easily remembered.) This is because each number represents a
particular combination of semi-independent properties, each of which has
separate rules for answers vs. offers.

It seems to me that it would be better to configure these distinct
properties independently. Perhaps just declare each of
{PAUSE,RESUME,PAUSED,REFUSED} that can be sent and received. (And for
convenience, perhaps some extra keywords for common combinations. (E.g.
"all".) Then the rules for valid answers for a given offer would be easy
to state and understand.

	Thanks,
	Paul Kyzivat, for the SDP Directorate