Re: [icnrg] draft-irtf-icnrg-icnlowpan-08.txt

Carsten Bormann <> Tue, 25 August 2020 22:26 UTC

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Date: Wed, 26 Aug 2020 00:26:19 +0200
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Subject: Re: [icnrg] draft-irtf-icnrg-icnlowpan-08.txt
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While we are resolving the code point issues, below are a few more questions I had.

Grüße, Carsten

# Major

An experimental RFC might want to specify a bit more about the experiment(s) that are planned to be made based on the protocol being defined.

In 5.3.2, how do I know that a Nonce is present?
(Optional in

8.1: What do these conceptual contexts do?
I find nothing about that in here.
(RFC 6775 Section 7.2 has rules about context state evolution that probably are needed here as well.)
8.3: The meaning of Context ID chaining is not explained.

# Minor

The term “time-value” is used for what appears to be a duration, not an absolute time.  (Also, Figure 29 is highly misleading.)

The discussion in Section 4.2 (as well as the Security Considerations for that) might benefit from a reference to
draft-ietf-6lo-minimal-fragment, in RFC editor queue.
Does icnlowpan have any opinion on fragment forwarding?

The term “link fragmentation” might more properly called “adaptation layer fragmentation”.

The neat unary encoding for NDN types assumes that type numbers stay low.
In uncompressed NDN, all numbers between 253 and 65535 have the same cost (three
bytes); here they have very different cost.
NDN might go ahead and allocate higher numbers without knowledge of the damage inflicted to the unary coding approach.
Looking at
it seems that only the range 800-1000 has been allocated at a (still
small) detriment to this unary scheme.
(I don’t think the design is wrong, I’m just thinking about ways to communicate the importance of small type numbers into the greater NDN space.)

5.2: Only the example says (implies) that the nibbles are used MSN first.

# Editorial

Define byte and nibble at the outset and simplify some of the text.