Subject: [MMUSIC] RFC4566 clarification: is 'image' media type registered?

From: "Kevin P. Fleming" <[email-masked]>
Date: Tue, 27 Jul 2010 09:26:53 -0500

While working with the ITU-T study group on a new revision of the T.38
recommendation, a proposal was made to update references in that
document that refer to RFC 2327 (Session Description Protocol) to refer
to RFC 4566 instead, which obsoletes it (and also RFC 3266).

However, in the course of reviewing the differences between RFCs 2327
and 4566, a possible sticking point arose. In RFC 2327, the possible
values for the 'media' type are documented as sharing the name space
with the top-level media content types in the MIME (RFC 2048) registry,
but in RFC 4566 this statement does not appear. RFC 4566 does contain
language that would appear to include such top-level media content types
as valid 'media' types in SDP, but also establishes a new SDP-specific
'media' type registry. The MIME top-level media content registry *does*
have a registration for 'image'.

If necessary, I can ask the relevant parties to send a official liaison
document to MMUSIC to ask this question, but in the meantime: is the
intent of the language in RFC 4566 to still allow all top-level media
content types in the MIME registry to be valid 'media' types in SDP, or
are the valid types only those listed in RFC 4566 itself and any that
might be later registered? I note that IANA does not appear to have
actually created an SDP media type registry (and populated it with the
values from RFC 4566), so the situation appears murky, at best :-)

-- 
Kevin P. Fleming
Digium, Inc. | Director of Software Technologies
445 Jan Davis Drive NW - Huntsville, AL 35806 - USA
skype: kpfleming | jabber: [email-masked]
Check us out at www.digium.com & www.asterisk.org

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From: OKUMURA Shinji <[email-masked]>
Date: Wed, 28 Jul 2010 11:06:37 +0900

Hi Kevin,

Colin Perkins had answered a similar question several years ago.

http://www.ietf.org/mail-archive/web/mmusic/current/msg03396.html

Regards,
Shinji

"Kevin P. Fleming" <[email-masked]>
Tue, 27 Jul 2010 09:26:53 -0500

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From: "Kevin P. Fleming" <[email-masked]>
Date: Fri, 30 Jul 2010 15:31:46 -0500

> http://www.ietf.org/mail-archive/web/mmusic/current/msg03396.html

Thank you for that; we'll proceed with producing a draft for
consideration by MMUSIC to register the 'image' media type for SDP.