Subject: [AVT] [Fwd: I-D ACTION:draft-jones-avt-audio-t38-00.txt]

From: Tom Taylor <[email-masked]>
Date: Tue, 12 Aug 2003 11:10:39 -0400

What's this all about?  First point is that image/t38 is already a registered MIME 
type.  Second point is that T.38 does NOT use RTP transport, in contradiction to the 
statement in the I-D that it does.

-------- Original Message --------
Subject: I-D ACTION:draft-jones-avt-audio-t38-00.txt
Date: Mon, 11 Aug 2003 15:46:16 -0400
From: [email-masked]
Reply-To: [email-masked]
To: IETF-Announce: ;

A New Internet-Draft is available from the on-line Internet-Drafts directories.

	Title		: Real-Time Facsimile (T.38) - audio/t38 MIME Sub-type
                           Registration
	Author(s)	: P. Jones
	Filename	: draft-jones-avt-audio-t38-00.txt
	Pages		: 4
	Date		: 2003-8-11
	
This document defines the MIME sub-type audio/t38.  The packetization
and usage of this MIME type, which is intended for use within SDP [2]
and H.248 [3] systems, is specified within ITU-T Recommendation T.38
[1].

A URL for this Internet-Draft is:
http://www.ietf.org/internet-drafts/draft-jones-avt-audio-t38-00.txt

To remove yourself from the IETF Announcement list, send a message to
ietf-announce-request with the word unsubscribe in the body of the message.

Internet-Drafts are also available by anonymous FTP. Login with the username
"anonymous" and a password of your e-mail address. After logging in,
type "cd internet-drafts" and then
	"get draft-jones-avt-audio-t38-00.txt".

A list of Internet-Drafts directories can be found in
http://www.ietf.org/shadow.html
or ftp://ftp.ietf.org/ietf/1shadow-sites.txt
...

_______________________________________________
Audio/Video Transport Working Group
[email-masked]
https://www1.ietf.org/mailman/listinfo/avt

---

From: "Paul E. Jones" <[email-masked]>
Date: Tue, 12 Aug 2003 22:21:31 -0400

Tom,

The purpose is to register the MIME type "audio/t38".  The reason is that
work is underway within ITU-T Q14/16 to support the carriage of T.38's IFP
packets through RTP.  This will allow us to then signal a single "m=" like
that looks like this:

  m=audio 5600 RTP/AVP 18 98
  a=rtpmap:98 t38/8000

When two media gateways have negotiated this (or similar) SDP and a fax tone
is detected on the line side, a mode shift may occur by simply transmitting
packets with PT=98, rather than PT=18.  This reduces the need for either
consuming additional UDP ports per call for image/t38 or going through a
lengthy exchange of messages to open a fax channel.

Paul

---

From: Colin Perkins <[email-masked]>
Date: Thu, 21 Aug 2003 18:34:51 +0100

Hi,

It seems that this draft needs more motivation and background 
information in the introduction, to make it clear exactly what is being 
registered and the scope of applicability for this MIME type. An 
additional section "Relation to RFC 3362" would also be appropriate, I 
believe.

I also have a number of other comments:

  - Bibliographic citations are not allowed in the abstract, you should 
move
    them into the introduction.
  - The "Conventions used in this document" section should be a numbered
    section, after the introduction.
  - The draft needs copyright and IPR notices adding
  - The current section 2 can probably be included under the "Encoding
    Considerations" header of the MIME registration.
  - Section 3 should be titled "IANA Considerations"
  - Section 3: The RTP timestamp rate is presumably a required parameter?
  - The draft needs a brief section explaining how the MIME name and any
    parameters are mapped onto SDP (e.g. see Section 5.1 of RFC 3557).
  - Security considerations needs to reference the security 
considerations
    of the RTP spec and any applicable profiles, along with any 
equivalent
    section in T.38 itself.
  - References need to be split into Normative and Informative sections.

You might also consider reading http://www.ietf.org/ID-nits.html where 
a lot of these issues are discussed.

Cheers,
Colin

-- 
Colin Perkins
http://csperkins.org/

---

From: "Paul E. Jones" <[email-masked]>
Date: Thu, 21 Aug 2003 13:58:03 -0400

Colin,

Thanks for the feedback.  I will try to incorporate your requests into a new
revision of the draft over the next few days.

Paul