[pim] draft-ietf-pim-gaap-18 ietf last call Tsvart review

[Tommy Pauly via Datatracker <[e-mail]>]

Document: draft-ietf-pim-gaap
Title: Group Address Allocation Protocol (GAAP)
Reviewer: Tommy Pauly
Review result: Ready with Nits

This document has been reviewed as part of the transport area review team's
ongoing effort to review key IETF documents. These comments were written
primarily for the transport area directors, but are copied to the document's
authors and WG to allow them to address any issues raised and also to the IETF
discussion list for information.

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Thanks to the authors for a clear and detailed document. As an experimental
document (where the experiment is clear, with a plan to update and revise
based on experience), I don't see any major concerns.

Some transport-specific aspects that are worth clarification:

- I appreciate the callout in section 7 for UDP usage guidelines, with
fragmentation called out. The document says that fragmentation SHOULD
be avoided on multi-record claim packets, and provides one example, but
could benefit from a stronger recommendation of a size to fit within
(such as 1232 to fit within a 1280 byte IPv6 packet).

- What are the expected scales of number of nodes participating? When
nodes send out periodic claims, I could imagine this having higher levels
of traffic if there is a very high number of nodes. Likely this is
something that needs to be understood via experimentation, but if there
is anything that can be said now about potential scalability concerns
with large numbers of nodes, that would be useful to call out.