Last Call Review of draft-ietf-lsr-flex-algo-23
review-ietf-lsr-flex-algo-23-opsdir-lc-dunbar-2022-09-21-00

I have reviewed this document as part of the Ops area directorate's ongoing
effort to review all IETF documents being processed by the IESG.  These
comments were written primarily for the benefit of the Ops area directors.
Document editors and WG chairs should treat these comments just like any other
last call comments.

This document specifies a set of extensions to IGP to enable multiple
topologies within one IGP domain, and each topology has its unique
constraint-based path computation metric.

It would be very helpful if Section 15 (Operational Consideration) included
some considerations on the number of topologies to be created for exemplary
deployments. Even though theoretically, hundreds/thousands of topologies can be
supported by the mechanisms described in the draft, in practice, probably only
a handful of (or even fewer) Flex-Algorithms are needed per IGP domain. It
would be so much easier to follow the document if knowing only two or three
Flex-Algorithm are needed.

Thank you
Linda Dunbar