[Pce] Shepherd review of draft-ietf-pce-state-sync

[Dhruv Dhody <[e-mail]>]

Hi Authors,

I have done the Shepherd review of the I-D. Once the update is posted, I
will send this to the AD.

# Shepherd review of draft-ietf-pce-state-sync

## Minor

- Section 3.3, "When a PCE receives a new PCRpt from a PCC without the
LSP-DB-VERSION, it SHOULD NOT forward the PCRpt on any state-sync sessions
and SHOULD log such an event on the first occurrence", when can the SHOULD
NOT be ignored? Otherwise make it a MUST NOT.

- Related to above, there are a lot of SHOULD in the draft, check them
against the IESG statement
https://datatracker.ietf.org/doc/statement-iesg-statement-on-clarifying-the-use-of-bcp-14-key-words/

- Section 3.5, "The computation priority is a number...", it is important
to go a little more in detail like an unsigned integer of range 0-7 (same
as delegation-pref in the PCEP YANG model) with 7 reflecting the highest
preference. Update the examples to keep the priority in this range.

- Section 3.5, "the highest IP address has more priority", we need to
handle the case for comparing IPv4 and IPv6 address as well, perhaps say
when comparan IPv4 address MUST first be converted to its IPv4-mapped IPv6
form [RFC4291] before comparison.

- Section 3.5, "...the operator MAY decide to instruct a switch-over to
delegate the LSP to the next highest priority PCE or to take back control
of the LSP. It is a local policy decision", is it the operator or the PCC?

- I suggest explicitly clarifying that the full mesh of PCEP sessions
between PCEs should be okay from scalability point of view. Perhaps in
Section 8.6? Something like - 'The “full mesh” requirement applies only
among PCEs that participate in inter-PCE state synchronization for the same
set of PCCs or associations. In operational deployments, this typically
involves a small number of PCEs (e.g., two or three for redundancy), making
a full mesh feasible for deterministic state consistency and loop
prevention.'


## Nits

- s/updates all PCEs/updates to all PCEs/

- Add reference on first mention of association groups

Thanks!
Dhruv