Gen-ART review of draft-ietf-avt-rtp-jpeg2000-beam-10.txt Tue, 17 June 2008 17:31 UTC

Return-Path: <>
Received: from [] (localhost []) by (Postfix) with ESMTP id 0524E3A6B5B; Tue, 17 Jun 2008 10:31:19 -0700 (PDT)
Received: from localhost (localhost []) by (Postfix) with ESMTP id 41A493A69AF; Mon, 16 Jun 2008 09:53:46 -0700 (PDT)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -6.599
X-Spam-Status: No, score=-6.599 tagged_above=-999 required=5 tests=[BAYES_00=-2.599, RCVD_IN_DNSWL_MED=-4]
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id LFtkkoM+F1lB; Mon, 16 Jun 2008 09:53:42 -0700 (PDT)
Received: from ( []) by (Postfix) with ESMTP id E34CA3A6920; Mon, 16 Jun 2008 09:53:41 -0700 (PDT)
Received: from ( []) by (Switch-3.2.5/Switch-3.1.7) with ESMTP id m5GGsG22013010 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Mon, 16 Jun 2008 12:54:16 -0400 (EDT)
Received: from ( []) by (Tablus Interceptor); Mon, 16 Jun 2008 12:35:13 -0400
Received: from ( []) by (Switch-3.2.5/Switch-3.1.7) with ESMTP id m5GGs9t1015360; Mon, 16 Jun 2008 12:54:11 -0400 (EDT)
Received: from ([]) by with Microsoft SMTPSVC(6.0.3790.1830); Mon, 16 Jun 2008 12:54:10 -0400
X-MimeOLE: Produced By Microsoft Exchange V6.5
Content-class: urn:content-classes:message
MIME-Version: 1.0
Subject: Gen-ART review of draft-ietf-avt-rtp-jpeg2000-beam-10.txt
Date: Mon, 16 Jun 2008 12:53:22 -0400
Message-ID: <>
Thread-Topic: Gen-ART review of draft-ietf-avt-rtp-jpeg2000-beam-10.txt
Thread-Index: AcjP0XyY+hZuajfxQ/WYNnXULKp2Qg==
To: <>, <>, <>, <>, <>, <>
X-OriginalArrivalTime: 16 Jun 2008 16:54:10.0609 (UTC) FILETIME=[993D1210:01C8CFD1]
X-Tablus-Inspected: yes
X-Tablus-Classifications: public
X-Tablus-Action: allow
X-Mailman-Approved-At: Tue, 17 Jun 2008 10:31:17 -0700
X-Mailman-Version: 2.1.9
Precedence: list
List-Id: IETF Discussion <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit

I have been selected as the General Area Review Team (Gen-ART) 
reviewer for this draft (for background on Gen-ART, please see 

Please wait for direction from your document shepherd 
or AD before posting a new version of the draft. 

Document: draft-ietf-avt-rtp-jpeg2000-beam-10.txt
Reviewer: David Black
Review Date: 16 June 2008
IESG Telechat date: 19 June 2008


This draft is on the right track, but has open issues,
described in the review.


The authors have only partially addressed the open issues noted in
the Gen-ART review of the -09 version.  More work is needed:

[1] The review of the -09 version stated: "Section 3.2 doesn't provide
information to calculate a packet priority value from layer, resolution
component values.  In fact the example it gives appears to be simple
to also be an example of the component based ordering defined in Section
Section 3.2 needs to explain how the priority value is calculated and
use a
more complex example to illustrate the results of the calculation."

In my opinion, Section 3.2, while improved, is still not clear enough to
be interoperably implemented in its current form.

A more complex example is now used, but the text does not state the
the algorithm used to generate the priority, nor does it provide the
specific algorithm for the example.

The general algorithm is that the ordering is based on the triple
<layer, resolution, component> and the minimum priority is 1, so, if
	- There are ltotal layers (layer value range is 0 to ltotal-1)
	- There are rtotal resolutions (resolution value range is 0 to
	- There are ctotal components (component value range is 0 to
then for a triple <lval, rval, cval>, 
	- priority = 1 + cval + (ctotal*rval) + (ctotal*rtotal*lval)
and for the example where ltotal=1, rtotal=2 and ctotal=3,
	- priority = 1 + cval + 3*rval
because lval=0 hence the  ctotal*rtotal*lval  term is zero (3*2*0)
and hence does not contribute to the priority computation.

[2] The review of the -09 version stated "Section 4.1 contains this
problematic text:

   An initial value of mh_id MUST be selected randomly between 1 and 7
   for security reasons."

This has been partially addressed.  While section 2.1 now requires that
the initial value of mh_id always be zero, the above "problematic text"
remains, and still needs to be removed from Section 4.1.

In addition, Security Considerations paragraph on mh_id concludes with
a rather cryptic statement that "Care should be taken to prevent
implementation bugs with potential security consequences."  Either
more specific guidance should be given, or the entire paragraph should
be removed, as mh_id does not appear to have any security value.

In addition, there is a new open issue:

[3] Section 7 does not appear to instruct IANA on what is to be done.
It appears that IANA should add the new parameters in section 5 to
the existing registration of a media type, but neither section 5
nor section 7 tells IANA what do to or which media type registration
is to be modified.


Reference [1] has still not been corrected.  The Gen-ART review of
the -09 version stated:

  Reference [1] should reference the Internet Draft by name.
   [1]  Futemma, "RTP Payload Format for JPEG 2000 Video Streams",
        RFC XXXY, April 2007.
  I believe this is draft-ietf-avt-rtp-jpeg2000-18.txt.  That should
  be in the reference instead of RFC XXXY.  Then add an RFC Editor
  note asking the RFC Editor to replace all instances of RFC XXXY
  with the RFC number assigned when reference [1] is published as an

The version of this draft has now advanced to -19.

idnits 2.08.04 flagged reference [1] as a possible problem,
and was confused by reference [3].  Reference [3] is fine as-is;
no change is needed.

David L. Black, Distinguished Engineer
EMC Corporation, 176 South St., Hopkinton, MA  01748
+1 (508) 293-7953             FAX: +1 (508) 293-7786        Mobile: +1 (978) 394-7754

IETF mailing list