Telechat Review of draft-ietf-babel-rtt-extension-05
review-ietf-babel-rtt-extension-05-intdir-telechat-fressancourt-2024-02-12-00

I am an assigned INT directorate reviewer for draft-ietf-babel-rtt-extension in
version 05. 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/
<https://datatracker.ietf.org/group/intdir/about/>.

Based on my review, if I was on the IESG I would ballot this document as YES.

The text of the draft is clearly written, and easy to follow. To the best of my
understanding, the metric, sub-TLVs and mechanisms described in the draft are
consistent with RFC 8966, in particular with the considerations for protocol
extensions in Appendix D.

The following are minor issues (typos, misspelling, minor text improvements)
with the document:

* In some parts of the draft, the authors personalize their text using "we" or
"our" (for instance in section 3.3 or in the introduction of section 4). The
authors might want to rephrase those sentences using a more neutral form.

* In section 4.1, I was frustrated by the use of vague terms like "fairly" or
"somewhat" which gives the impression that the phenomenon described is
difficult to observe, and may not require the use of a proper smoothing
algorithm.

* In section 4.1 and 4.3, the text mentions external references to describe
algorithms that the implementer could be using to avoid strong oscillations in
the route selection algorithm. I would have appreciated to have a rough
intuition of the behavior of those algorithms in the text directly, while
keeping the reference to point to more detailed descriptions.