Subject: Re: [MMUSIC] I-D Action: draft-ietf-mmusic-rfc4566bis-04.txt

From: OKUMURA Shinji <[email-masked]>
Date: Wed, 30 Nov 2011 18:34:27 +0900

Hi,

I have some questions concerning draft-ietf-mmusic-rfc4566bis-04.

[Page 25]
    "If the <proto> sub-field is "udp" the <fmt> sub-fields MUST
    reference a media type describing the format under the "audio",
    "video", "text", "application", or "message" top-level media
    types.  The media type registration SHOULD define the packet
    format for use with UDP transport."

Q1. In this document, there are some "media type",
    "top-level media content types", "top-level content type"
    and "top-level media types".

    Which do these mean "MIME media type" or "SDP media type"?
    Or do the both of two have the same meaning?
    I think these are ambiguous expressions.

Q2. As for the "audio", "video", "text", "application", or "message"
    top-level media types, where is the definition of the packet
    format for use with UDP transport?
    Why is it necessary for new media types?

[Page 36]
8.2.3.  Media Formats ("fmt")
    "For the "udp" protocol, new formats SHOULD be registered.  Use of an
    existing media subtype for the format is encouraged.  If no media
    subtype exists, it is RECOMMENDED that a suitable one be registered
    through the IETF process [RFC4288] by production of, or reference to,
    a standards-track RFC that defines the transport protocol for the
    format."

Q3. When a new media format(such as t38) is registered, 
    why should we define a new format for "udp" protocol?
    IMHO all media format don't need the "udp" protocol.

Regards,
Shinji

[email-masked]
Mon, 24 Oct 2011 10:57:30 -0700
>A New Internet-Draft is available from the on-line Internet-Drafts
>directories. This draft is a work item of the Multiparty Multimedia
>Session Control Working Group of the IETF.
>
>	Title			: SDP: Session Description Protocol
>	Author(s)		: Mark Handley
>						   Van Jacobson
>						   Colin Perkins
>						   Ali Begen
>	Filename		: draft-ietf-mmusic-rfc4566bis-04.txt
>	Pages			: 49
>	Date			: 2011-10-24
>
>	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.
>
>
>A URL for this Internet-Draft is:
>http://www.ietf.org/internet-drafts/draft-ietf-mmusic-rfc4566bis-04.txt
>
>Internet-Drafts are also available by anonymous FTP at:
>ftp://ftp.ietf.org/internet-drafts/
>
>This Internet-Draft can be retrieved at:
>ftp://ftp.ietf.org/internet-drafts/draft-ietf-mmusic-rfc4566bis-04.txt