Early Review of draft-ietf-rtgwg-segment-routing-ti-lfa-09
review-ietf-rtgwg-segment-routing-ti-lfa-09-rtgdir-early-smith-2023-06-25-00

Summary:

Thank you for writing this document.

This document is well written. I think that it is ready to be published,
but there are a few points below that I would like to discuss for
clarification. I also spotted a few nits that should be fixed at some point
before publication.

Comments and Questions:

I would like to see some more detailed examples of capacity planning in
TI-LFA environments.   The document touches on this to some degree, but a
few illustrations showing how to accommodate some topological scenarios -
'valley free' routing, dissimilar interface speeds, cases where ECMP isn't
always feasible, etc would be helpful.   Some topological case studies and
the effect TI-LFA has on the network would be helpful to the operator when
designing the network.

Nits:

 - Avoid gratuitous promotional language (weasel words) like "Thanks to SR"
--> not necessary

 - "it looks interesting to steer the traffic onto the post-convergence
path" --> poor english

 - "w.r.t." --> this is used throughout the document, expand it to 'with
regard to' or rework the sentence

 - "used by the repair path is recored" --> spelling error

 - Rework this sentence:

   "1 SID repair paths are sufficient to protect more than 99% of the
prefix in almost all cases"

   should read:

   "1 SID repair path is sufficient to protect more than 99% of the
prefixes in almost all cases"

 - "only 1 SID is needed to guarantee loop-freeness" --> Awkward use, is
'freeness' a word?