Re: [MMUSIC] Opsdir last call review of draft-ietf-mmusic-rfc4566bis-34

Paul Kyzivat <> Wed, 10 April 2019 20:23 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id B622C12021D; Wed, 10 Apr 2019 13:23:37 -0700 (PDT)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -1.9
X-Spam-Status: No, score=-1.9 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id EY46DygoMXsR; Wed, 10 Apr 2019 13:23:36 -0700 (PDT)
Received: from ( []) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by (Postfix) with ESMTPS id E8360120165; Wed, 10 Apr 2019 13:23:35 -0700 (PDT)
Received: from PaulKyzivatsMBP.localdomain ( []) (authenticated bits=0) (User authenticated as pkyzivat@ALUM.MIT.EDU) by (8.14.7/8.12.4) with ESMTP id x3AKNRgx021968 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=NOT); Wed, 10 Apr 2019 16:23:27 -0400
To: wangzitao <>, "" <>
Cc: "" <>, "" <>, "" <>
References: <>
From: Paul Kyzivat <>
Message-ID: <>
Date: Wed, 10 Apr 2019 16:24:53 -0400
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:60.0) Gecko/20100101 Thunderbird/60.6.1
MIME-Version: 1.0
In-Reply-To: <>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 8bit
Archived-At: <>
Subject: Re: [MMUSIC] Opsdir last call review of draft-ietf-mmusic-rfc4566bis-34
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Multiparty Multimedia Session Control Working Group <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Wed, 10 Apr 2019 20:23:38 -0000

Please see inline.

On 4/9/19 11:03 PM, wangzitao wrote:
> Hi Paul,
> Please find my comments at [MW].
> B.R.
> -Michael
> -----邮件原件-----
> 发件人: Paul Kyzivat []
> 发送时间: 2019年4月10日 1:11
> 收件人: wangzitao <>om>;
> 抄送:;;
> 主题: Re: [MMUSIC] Opsdir last call review of draft-ietf-mmusic-rfc4566bis-34
> Thank you for the comments. I have some questions:
> On 4/8/19 2:37 AM, Zitao Wang via Datatracker wrote:
>> Reviewer: Zitao Wang
>> Review result: Has Issues
>> Summary:    This memo defines the Session Description Protocol (SDP).  SDP is
>> intended for describing multimedia sessions for the purposes of
>> session announcement, session invitation, and other forms of
>> multimedia session initiation.  This document obsoletes RFC 4566. I
>> think the document make sense and is written very clear, except some small nits:
>> # In Section 5, there are
>> several terms that miss references, such as "US-ASCII subset of
>> UTF-8",  "ASN.1 or XDR", etc.
> There is already a reference to the definition of UTF-8 [RFC3629] in section 4.5. Do you think the reference needs to be included with every use? The US-ASCII subset of UTF-8 is also defined in RFC3629, so I am inclined to use the same reference for that. There are also a couple of uses of US-ASCII without mention of UTF-8. I'm inclined to change those to "the US-ASCII subset of UTF-8".

I changed the naked uses of US-ASCII to reference the US-ASCII subset of 
UTF-8. I also added another reference to RFC3629 to the *first* use of 
"US-ASCII subset of UTF-8". I haven't added references to other places 
with the same usage.

> Regarding ASN.1 and XDR, I can add references if you think it important.
> But their use is very peripheral, and it isn't necessary to know what they are to read the text.
> [MW]: I am OK if it is not commonly used.
> # s/session- specific/session-specific/
> Regarding "session- specific" vs. "session-specific":
> The context for this is:
> "Attribute scopes in addition to media- and session- specific may also..."
> The space was intentional so that there are equivalent constructions for "media" and "session". The intent is as a shorthand for:
> "Attribute scopes in addition to media-specific and session-specific may also..."
> To avoid confusion I think I'll just change to the latter.
> [MW]: I agree.


> # Suggest to add tags on
>> "overview optional items" to identified now-obsolete items, such as
>> "a=cat", "a=keywds", "k=".
> I'm not clear what you want me to do.
> I guess you are suggesting adding something to the first figure in section 5.
> [MW]: Yes, IMO, adding some tag/description to the figure is better.
> I don't see how that would be possible for a=cat and a=keywds, since the figure doesn't mention individual attributes.
> [MW]: Agree. For a=cat and a=keywds, it is difficult to show on the figure.
> While it is possible to add something for k=, IMO it is better to leave that level of detail to the complete description in section 5.12.
> [MW]: Maybe it can be updated as following:
>        Before :
>         k=* (encryption key)
>        After:
>         k=* (encryption key, this line is obsoleted)

I changed these to

           k=* (obsolete)

I have these changes in my working copy for inclusion the next time I 
submit a revision.