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

wangzitao <> Wed, 10 April 2019 03:03 UTC

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From: wangzitao <>
To: Paul Kyzivat <>, "" <>
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Thread-Topic: [MMUSIC] Opsdir last call review of draft-ietf-mmusic-rfc4566bis-34
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Subject: Re: [MMUSIC] Opsdir last call review of draft-ietf-mmusic-rfc4566bis-34
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Hi Paul,

Please find my comments at [MW].


发件人: Paul Kyzivat [] 
发送时间: 2019年4月10日 1:11
收件人: wangzitao <>om>;
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".

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)
       k=* (encryption key, this line is obsoleted)

	Paul Kyzivat