Subject: [ippm] Mirja Kühlewind's No Objection on draft-ietf-ippm-model-based-metrics-11: (with COMMENT)

From: Mirja Kühlewind <[email-masked]>
Date: Tue, 01 Aug 2017 05:33:30 -0700

Mirja Kühlewind has entered the following ballot position for
draft-ietf-ippm-model-based-metrics-11: No Objection

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COMMENT:
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High level comment:
I still (compared to an earlier review I did during the first wg last call)
think that the document could benefit from a mayor editorial pass that aims to
remove redundancy (especially in section 8) and hopefully would lead to a much
shorter document in the end. Especially the split between section 6, 7 and 8 is
not always clear. It would actually be nice if the general model aspects and
its applicability to one traffic class with the assumption that self-clocked,
loss/CE-based congestion control is used would be separated more clearly. This
would also help to separate generally reasoning from the test and evaluation
instructions and make those more clear and understandable (in the sense that
concrete implementation guidelines for both the tests and the evaluation seem
quite hidden between all the other text at the moment). However, I understand
that this is a lot of work and probably not appropriate at this state of
processing.

Processing comment:
The references are not split into normative and informative. I guess most
references including draft-ietf-tcpm-rack are informative. Indicating this
clearly in two separate reference sections would also address the editor
comment in 1.1 regarding draft-ietf-tcpm-rack.

Various, mostly editorial comments:
- The terminology mentions open loop. I would recommend to also note in the
intro that these are open loop tests (compared to using TCP traffic directly).
- ECN should be spelled out somewhere and RFC3168 should be referred
(informatively). - It seems that the currently specified metrics and tests
assume ack-clocked and loss/ECN-based congestion control. This might also worth
stating in the intro given quic is experimenting with rate-based schemes. -
Regarding the list at the end of section 4.1 on bursts: Shouldn't the initial
window (which is usually today more than 4 packets) be mentioned additionally?
- Network power could be defined in the terminology section. - It might also be
useful to spell out more clearly in the intro that for these tests both
endpoints (of the subpath under test) need to be under control of the tester. -
As mentioned several times in the document, some of the tests are not intended
for frequent monitoring tests as the high load can impact other traffic
negatively. This should be re-stated clearly  in the security considerations.

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From: Spencer Dawkins at IETF <[email-masked]>
Date: Wed, 2 Aug 2017 12:57:53 -0500

Just checking ...

> https://datatracker.ietf.org/doc/draft-ietf-ippm-model-based-metrics/

This is on tomorrow's telechat. Any thoughts from the authors/working group
about Mirja's comments?

Thanks,

Spencer