Subject: [ippm] Éric Vyncke's No Objection on draft-ietf-ippm-ioam-data-12: (with COMMENT)

From: Éric Vyncke via Datatracker <[email-masked]>
Date: Thu, 25 Mar 2021 01:34:46 -0700

Éric Vyncke has entered the following ballot position for
draft-ietf-ippm-ioam-data-12: No Objection

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COMMENT:
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Thank you for the work put into this document and thank you for acknowledging
my comments and advices (as they were minor, I am not recusing myself).
Sometimes the text is difficult to read as paragraphs and sentences are long
and somehow repetitive.

Please find below  some non-blocking COMMENT points (but replies would be
appreciated), and some nits. Like Alvaro, I was hesitating to ballot a DISCUSS
on one point about section 4 (insertion/deletion of data on the flight).

I hope that this helps to improve the document,

Regards,

-éric

== COMMENTS ==

-- Abstract --
"a path between two points in the network" does this mean that this document
cannot be used with a multicast destination address ?

-- Section 2 --
Is the list about 'contributors' (as in the section title) or 'co-authors' (as
in the text) ?

-- Section 3 --
Please use the BCP14 boilerplate

Please note that Geneve is now RFC 8926.

-- Section 4 --
Should the 'deployment domain' include a reference to RFC 8799 ?

I was about to ballot a DISCUSS on this one: While the actual encapsulation is
out of scope, the definition of "IOAM control points" alludes to nodes at the
edge and in the core being able to add/remove data fields. This behavior will
obviously have some impacts on the PMTU discovery and possibly on the handling
of ICMP. Did the authors think of writing a generic section in this document on
how this can be done in a correct way?

What is "live user traffic" ? I guess that this is not about end-user real-time
video ;-) but a better wording would be welcome.

I am afraid that "ships in the night" does not apply here as all ships are
usually on the same layer ;-) (planes do flight at different flight levels)
But, this is not that important. No need to reply.

-- Section 5.1 --
Is it expected to have additional IOAM data types than the 4 in this document?
Text should clarify this.

-- Section 5.2 --
"A transit node MUST NOT add new IOAM-Option-Types" seems to contradict the
"IOAM control points" definition of section 4.

-- Section 5.3 --
If 0x0000 is already reserved, then I would suggest to make it part of the IANA
range (i.e., making IANA range 0x0000 t 0x7FFF).

-- Section 5.4.2.5 --
Should there be a precise definition (or reference) of "time in nanoseconds the
packet spent in the transit node"? E.g., between first bit received and last
bit sent ?

-- Section 5.4.2.7 --
Is there a reason why the queue depth is expressed in buffers and not in
packets? (Both metrics have useful values imho)

-- Section 5.5 --
In "Random: Unique identifier for the packet" how are collisions resolved? Do
they matter at all ?

How can a transit/decaps node can handle the PoT (and also the E2E of section
5.6) as the length is not specified in the header ?

== NITS ==

Usually "e.g." is enclosed between commas.

The sentence "The definition of how IOAM-Data-Fields are encapsulated into
other protocols is outside the scope of this document." or a minor variation of
it occurs multiple times in the document. Please consider avoiding those
repetitions.