Subject: [6lo] Éric Vyncke's No Objection on draft-ietf-6lo-fragment-recovery-13: (with COMMENT)

From: Éric Vyncke via Datatracker <[email-masked]>
Date: Wed, 19 Feb 2020 05:07:03 -0800

Éric Vyncke has entered the following ballot position for
draft-ietf-6lo-fragment-recovery-13: No Objection

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COMMENT:
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Pascal, thank you for the work put into this document.  The idea is simple and
smart, I like the fact that all fragments follow the same path, so they should
be delivered in the right order.

Nevertheless, please find below some non-blocking COMMENTs (and I would
appreciate a response from the authors) and NITS.

I hope that this helps to improve the document,

Regards,

-éric

== COMMENTS ==

A generic question is whether RFC 7112 "Implications of Oversized IPv6 Header
Chains" is applicable ?

-- Section 4.2 and Section 7.1 --
Should default values for the inter-frame gap be given ?

-- Section 5.1 --
With 8 bits in the Datagram_Tag, this means that a node can only
transmit/forward 256 packets over a link. While this seems suffisant, did the
author make some investigation on this limit? The text should also state what
to do when the 8 bits are not enough.

-- Section 5.2 --
I suggest to mention that the use of the Datagram_Tag field will be described
in section 6.

-- Section 6 --
I find it weird to read in the same paragraph "The RFRAG Acknowledgment can
optionally carry an ECN" and later "MUST echo that information by setting the
'E'". I am not a native English speaker but may I suggest to replace the first
part with "The RFRAG Acknowledgment has a ECN"

-- Section 6.1.2 --
"An implementation may receive overlapping fragments as the result of retries
after an MTU change." Is this a security risk (RFC 8200 forbids overlapping
fragments but this is a different layers) ? I also suggest to make it a
normative "MAY" or "MUST accept".

-- Section 7.2 --
Should the network observation installs global states or per destination states
? E.g., typical IP implementations maintain a per destination Path MTU cache.

== NITS ==

-- Section 7 --
Is it "Kbps" or "kbps" ?