Subject: [Int-dir] INTDIR review of draft-ietf-6lo-deadline-time-02

From: Donald Eastlake <[email-masked]>
Date: Fri, 21 Sep 2018 14:50:30 -0400

I am an assigned INT directorate reviewer for
<raft-ietf-6lo-deadline-time-02.txt>. These comments were written
primarily for the benefit of the Internet Area Directors. Document
editors and shepherd(s) should treat these comments just like they
would treat comments from any other IETF contributors and resolve them
along with any other Last Call comments that have been received. For
more details on the INT Directorate, see
https://datatracker.ietf.org/group/intdir/about/.

This draft looks pretty good but there are a number of minor issues,
many editorial, listed below, that I think should be addressed before
it goes to IETF Last Call:

Section 1: Suggest adding a reference for Wi-SUN and maybe "BLE mesh"
at the end of Section 1.

Section 2: Update the implementation requirement key word boilerplate
and add RFC 8174 as a normative reference.

Section 3: Should there be a more precise definition of Origination
Time? When the packet is de-queued for transmission or when the first
bit is sent, or when the last bit is sent, or whatever...

Section 3: It is unfortunate that the acronyms for Absolute Slot
Number and Autonomous System Number collide but ASN is only used in
the first sense in this document and I assume, due to use in other
documents, it would be impractical to change it.

Section 3, middle of page 4, suggest changing
    Departure time of packet in the network 'x'
to
    Departure time of packet from the network 'x'

Section 4, page 6:
    For DTL and OTL, the example makes it moderately clear, except
when the DT or OT is not present, but I would prefer for it to say
something like "An unsigned integer that is one less than the length
of the XX field when that field is present."
    For "Rsv" bits, need to say "sent as zero and ignored on receipt."
    For DT Value and OT Value, I really don't like the parenthetical
which implies that, for example, the DT Value can be any length from 8
to 64 bits, for example, it might be 13 or 27 bits, since it looks
like it must be an integer number of octets. (At least, if it can be
some odd number of bits, you need to say if it is left justified or
right justified and how the unused bits are filled.) I suggest
something like (for Deadline Time as an example) "An unsigned integer
of DTL octets giving the Deadline Time value."

Section 5.1, top of page 8: suggest using "removed" instead of the
less common word "elided".

Section 5.2, first paragraph, if you are going to say "the new time
synchronized network" then probably the word "New" should be inserted
into the box at the top of Figure 5. Perhaps better to use "Other"
rather than "New" in both places "New" is currenlty used in the text
and in the Figure.

Section 5.3, first paragraph, suggest replacing
   For the route segment from 'S' to 6LBR, 'S' includes the Deadline-
   6LoRHE.  Subsequently, each 6LR will perform hop-by-hop operation to
   forward the packet towards the 6LBR.
with
   'S' includes the Deadline-6LoRHE.  Subsequently, each 6LR will perform
   hop-by-hop operation to forward the packet towards 6LBR1.

Section 5.3, Perhaps this should clarify what the "border router" is.
Maybe "6LBR1 or 6LBR2".

Section 6, suggest replacing "assigns" with "IANA is requested to
assign" and add, at the end of that sentence, "for this purpose".

I did not review the references or change history.

Thanks,
Donald
===============================
 Donald E. Eastlake 3rd   +1-508-333-2270 (cell)
 1424 Pro Shop Court, Davenport, FL 33896 USA
 [email-masked]