Subject: [Gen-art] RE: Gen-art review of draft-ietf-rmt-fec-bb-revised-06

From: Elwyn Davies <[email-masked]>
Date: Sun, 15 Apr 2007 20:09:40 +0100

I see this is up for the IESG telechat this week.

For the record I have not seen any response to my comments below to date (15 
April).  These were copied to authors and document shepherd.

/Elwyn

=========================

I have been selected as the General Area Review Team (Gen-ART)
reviewer for this draft (for background on Gen-ART, please see
http://www.alvestrand.no/ietf/gen/art/gen-art-FAQ.html).

Please resolve these comments along with any other Last Call comments
you may receive.

Document: draft-ietf-rmt-fec-bb-revised-06.txt
Reviewer: Elwyn Davies
Review Date:  11 April 2007
IETF LC End Date: 12 April 2007
IESG Telechat date: (if known) -

Summary:
Almost ready for PS.  There are some minor issues and editorial nits that should 
be addressed before it goes to the IESG.

Comments:

Minor Issues:
s6:  As well as data packets, para 1 introduces session-control and
feedback packets, but then para 4 says that we are specifying stuff
about data packets.  Session-control and feedback packets disappear into
the void.  Some words about what is or is not specified about these
other kinds of packets would help - even if only to say they are out of
scope.

s6.1:  The implication of the last para is that an 8 bit field is enough
to hold the FEC Encoding ID (confirmed more or less in 6.2.3).  2 * 128
possible values may be enough but given that proprietary schemes are
allowed and lots of different CDPs might have different schemes, one
wonders if this might be constraining - and I see no means of expanding
the range. Justify?  Also there isn't an experimental range.

s6.2.1, para 4: Make it explicit whether the choice of (a) or (b) for
the encoding is allowed to be per object or per CDP/FEC Scheme.  Even
though it is probably obvious, it would be wise to state that if there
is an option the CDP has to provide means to transmit which choice has
been made.

s6.2.1, last para: The statements about the length of the field read as
if there has been previous statements about the length of Common Object
encodings.  There hasn't been.  Either reword to cover all lengths here
or add words to the earlier paragraphs about the Common Objects.

s6.3:  I would have expected (I think) that a maximum range for FEC
Payload IDs should be given to give a hint to CDPs on the field size
needed, but I may be wrong - perhaps some words of explanation as to why
it is not needed (if that is the case) would help others.

s11: Should we still be, even indirectly, suggesting that MD5 would be a
suitable hash functtion?

Editorial
=========
Global: s/[Aa]n FEC/[Aa] FEC/ (OK, maybe an sounds more euphonious but
it is wrong).  I'm sure the RFC Editor will have a view.

Global: Prefer octet rather than byte.

s1: It would be good to explicitly state the section (4.2 I assume) of
RFC 3048 ([10]) which this draft covers.

s1: Worth expanding RMT for future generations (or remove the note about
the wg that produced it).

s1, para 6: Helpful to add a forward ref to s4 or s6.1 where
Fully/Under-Specified are defined.

s4, para 1:  'A FEC code is a valuable component...':  I am not sure if
this the best phraseology.  Maybe: A FEC coding scheme is a valuable
component...  Actually I found the term 'FEC code' somewhat distracting
throughout - it doesn't sound quite right when referring to the adjuncts
needed to provide the extra FEC information and the encoding used to
generate them.

s4, para 4: s/ancilliary/anciliary/ (last instance)

s5, para 1: Might be good to refer explicitly to s3.2 of RFC 2357.

s6.1, para 5: s/FEc/FEC/

s6.2.2, paras 2 and 3:  It would be better to start these paras with
'Any' rather than 'The'.  At present it is very easy to read paras 2 and
3 as contradictory.

s6.2.4, last para: s/EXT-FTI/EXT_FTI/.  Also need to expand LCT acronym.

s6.3, last para:  The term 'systematic FEC codes' appears to be a term
of art that is not defined.  Explanation would be appreciated.

s11: s/to many receivers/at many receivers/

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---

From: Magnus Westerlund <[email-masked]>
Date: Mon, 16 Apr 2007 09:36:48 +0200

> April).  These were copied to authors and document shepherd.

Elwyn, you need to include the responsible AD also when you send these. 
Otherwise I have no idea that comments has come in and needs to be 
handled. In fact if you want them to really count as IETF last call 
comments they should be sent to [email-masked] list.

Sure, the shepherd should help ensure that I know about these comments 
but to avoid issue when the shepherd is on vacation etc. Please do the 
right thing directly

Having said that, Authors you better respond ASAP and include me in the 
discussion.

Cheers

Magnus Westerlund

IETF Transport Area Director & TSVWG Chair
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