[Int-dir] draft-ietf-tvr-requirements-08 telechat Intdir review

[Darren Dukes via Datatracker <[e-mail]>]

Document: draft-ietf-tvr-requirements
Title: Time-Variant Routing (TVR) Requirements
Reviewer: Darren Dukes
Review result: Ready with Nits

## Overall Observations
The document is  well structured and comprehensive, and the writing was clear
and precise. It provided me a good foundation for understanding the concepts of
TVR and the requirements for the design and implementation of systems which
perform TVR and their different aspects.

It's worth noting I did not find any major issues, but I did find myself
wanting more diagrams to visualize the topic, this is a personal preference to
aid and verify my understanding of the text and my be considered. The remainder
of this review is focused on minor edits and suggestions for improvmement that
don't materially change the document but may help implementers.

## Typo's and minor edits

Section 1.1 s/goverened/governed/ (typo)
Section 2.2 s/invarient/invariant/ (typo)
Section 2.2.1 s/This is the temporality model of [AIXM]./This is the
temporality model of Aeronautical Information Exchange Model [AIXM]./ (missing
acronym expansion) Section 2.4.2 s/may distributed/may be distributed/ (typo)
Section 2.5 s/Specific security considerations are discussed in the Section 6.
later in this document./Specific security considerations are discussed in
Section 6 later in this document./ (extra the) Section 3.1
s/phenomina/phenomena/ (typo) Section 4.3 s/as described in 3.1/as described in
Section 3.1/ (missing link and "Section") Section 6.5 s/Replay Attacks on
Time-Sensitive Data: Time variant network data.../Time-variant network data.../
(title replay and hyphenation) Section 6.6 s/Compromised Time Sources: The
reliance on.../The reliance on.../ (title replay)

## Inconsistencies in normative language
Use of should or must is present in this informational document, which is
understandable in the requirements section. But when should is used the
document provides no clear consequence for non-compliance. Some examples:
section 3.2 (what happens if management entities cannot provide updates as fast
as needed), 4.1 (what happens if a manager does not provide an advertisement
methodology for responding to abnormal changes).

## State propagation
Section 2.3 Topologies - There's some ambiguity/inconsistency with respect to
state propagation from nodes links and TPs. The text says "may define an
interpolation method" for nodes and TPs "should define an interpolation method"
for links It wasn't obvious to me why a node state impacts a link state since
"Nodes also contain termination points that anchor the links."  but in my
experience links are independent of the node or TP state.