Re: [MMUSIC] Review of 4566bis

Paul Kyzivat <pkyzivat@alum.mit.edu> Tue, 02 June 2015 13:50 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 CF9FD1A0113 for <mmusic@ietfa.amsl.com>; Tue, 2 Jun 2015 06:50:51 -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 Qc4WiErPK5UP for <mmusic@ietfa.amsl.com>; Tue, 2 Jun 2015 06:50:50 -0700 (PDT)
Received: from resqmta-ch2-01v.sys.comcast.net (resqmta-ch2-01v.sys.comcast.net [IPv6:2001:558:fe21:29:69:252:207:33]) (using TLSv1.2 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 18AAB1A008F for <mmusic@ietf.org>; Tue, 2 Jun 2015 06:50:49 -0700 (PDT)
Received: from resomta-ch2-08v.sys.comcast.net ([69.252.207.104]) by resqmta-ch2-01v.sys.comcast.net with comcast id bRpG1q0022Fh1PH01RqpL6; Tue, 02 Jun 2015 13:50:49 +0000
Received: from Paul-Kyzivats-MacBook-Pro.local ([50.138.229.151]) by resomta-ch2-08v.sys.comcast.net with comcast id bRqo1q00a3Ge9ey01Rqo6G; Tue, 02 Jun 2015 13:50:49 +0000
Message-ID: <556DB4B7.30502@alum.mit.edu>
Date: Tue, 02 Jun 2015 09:50:47 -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: Christer Holmberg <christer.holmberg@ericsson.com>, Roni Even <ron.even.tlv@gmail.com>, "mmusic@ietf.org" <mmusic@ietf.org>
References: <7594FB04B1934943A5C02806D1A2204B1D873B05@ESESSMB209.ericsson.se> <556B4841.605@alum.mit.edu> <081901d09cb3$6b4c35a0$41e4a0e0$@gmail.com> <7594FB04B1934943A5C02806D1A2204B1D879D41@ESESSMB209.ericsson.se>
In-Reply-To: <7594FB04B1934943A5C02806D1A2204B1D879D41@ESESSMB209.ericsson.se>
Content-Type: text/plain; charset=windows-1252; format=flowed
Content-Transfer-Encoding: 7bit
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=comcast.net; s=q20140121; t=1433253049; bh=4SquqkbanMKO1fw8ecUs53EvL4IRm5C5Au7qBvA9gyk=; h=Received:Received:Message-ID:Date:From:MIME-Version:To:Subject: Content-Type; b=iQEXx1ZHxWsL5ZcAsGInKgI0rmA6H0fndF/FKbNUipjzAAtXD0UROSBR3aXmh2MuN pE3FPFz75IGgF5HQ5FNpYglc7vCNRFHIGiQUmOQZM5Rf+hxUZsVOI477aVUxsBMeyc ltCGKjmDUp4NC/IMu7vx742X176LervWd45XhA1MzsVFzPBsB70nYVR1qiJRTMSxiH LKmbC5FA+9gBPXvAsBKV+8YhbIdnbZdJr0XL1uQKOSJ88tCQMCC59pPCXoOUkHwhwk r9L5DfKDkIHeUwgKtxHDBXjpqp5dRibtlYa0Sqve1vWhvFbJhetFHklXxg2+nkxPOW jIQSBR+oc+zbw==
Archived-At: <http://mailarchive.ietf.org/arch/msg/mmusic/FoCDearzs_NlRjHGzy3tsaOzIfc>
Subject: Re: [MMUSIC] Review of 4566bis
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: Tue, 02 Jun 2015 13:50:52 -0000

On 6/2/15 5:02 AM, Christer Holmberg wrote:
> Hi Roni,
>
>> I do not think that general media level overrides session level value works for the b= attribute Roni
>
> b= is not an attribute :)
>
> Anyway, my suggestion would be that the DEFAULT RULE for all SDP elements that can occur both on session and media level should be that the media level overrides the session level. Then, in cases where it does not apply, it should be explicitly stated.

I do think this *would have been* the right thing to do from the 
beginning. But I am uncertain if it is the right thing to do *now*, for 
backward compatibility reasons.

Before doing so we will need to do an exhaustive study of all current 
attribute definitions that are registered in IANA as valid at both 
session and media level - to ensure that their meaning won't be changed 
by this.

	Thanks,
	Paul

> Regards,
>
> Christer
>
>> -----Original Message-----
>> From: mmusic [mailto:mmusic-bounces@ietf.org] On Behalf Of Paul
>> Kyzivat
>> Sent: 31 May, 2015 8:43 PM
>> To: mmusic@ietf.org
>> Subject: Re: [MMUSIC] Review of 4566bis
>>
>> On 5/31/15 9:38 AM, Christer Holmberg wrote:
>>
>> Good list Christer!
>>
>> I have comments on a few of your issues:
>>
>>> Q6_2:
>>>
>>> In some of the sub-sections, it is indicated that a media-level
>>> attribute value overrides a session-level attribute value. As far as
>>> I know, that applies to all attributes (that can be present both on
>>> the session-level and media-level), so there should be a generic
>>> statement about that.
>>>
>>> This is similar to the comment on the c= line.
>>
>> I used to think this, but I think there are some exceptions. (But I
>> don't
> offhand
>> remember what they are.)
>>
>>> Section 6.7:
>>>
>>> ---------------
>>>
>>> Q6-7_1:
>>>
>>> The text says:
>>>
>>>      "If any one of these appears in a media section then it applies
>>> for
>>>
>>>      that media section.  If none appear in a media section then the
>>> one
>>>
>>>      from session level, if any, applies to that media section."
>>>
>>> There should be a general statement in the draft about session level
>>> information applying to the media level.
>>
>> I wish there could be a general statement, but it is hard, given
> exceptions.
>> Perhaps there could be a general statement with note that it can be
> overridden
>> in particular cases.
>>
>> But in any case, *this* is different, because it says that the
>> presence of
> any
>> *one* of four different attributes at media level overrides the
>> presence
> of any
>> one of those four at session level.
>>
>>> Section 6.11:
>>>
>>> -----------------
>>>
>>> The text says that the attribute "specifies the language" of the
>>> session description.
>>>
>>> There has been some confusion about what that really means, so I
>>> think it would be good to clarify that it applies to any textual
>>> information that may be provided within the description.
>>>
>>> It would also be good to explicitly indicate that the attribute is
>>> not related to languages used in the actual media streams.
>>
>> +1
>>
>> 	Thanks,
>> 	Paul
>>
>> _______________________________________________
>> mmusic mailing list
>> mmusic@ietf.org
>> https://www.ietf.org/mailman/listinfo/mmusic
>
> _______________________________________________
> mmusic mailing list
> mmusic@ietf.org
> https://www.ietf.org/mailman/listinfo/mmusic
>