Subject: [Last-Call] Tsvart last call review of draft-ietf-pim-drlb-13

From: Michael Scharf via Datatracker <[email-masked]>
Date: Tue, 29 Oct 2019 10:47:52 -0700

Reviewer: Michael Scharf
Review result: Ready

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.

When done at the time of IETF Last Call, the authors should consider this
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As far as I can see there are no fundamental transport-related issues in this
document. All in all, the impact of selecting a Group Designated Router may be
quite similar to the existing PIM-SM selection of a Designated Router.

A little bit of wordsmithing: In Section 6, it could be useful to replace the
term "enough total capacity" by another term, such as "enough available
capacity" or "enough spare capacity". The router links can obviously also carry
other, non-PIM traffic. Then there must be enough available bandwidth left for
the PIM traffic on top of non-PIM traffic. The term "total capacity" is a bit
vague; it could possibly refer to the physical link capacity (e.g., 1 Gbit/s
for Gigabit Ethernet). Only considering the physical link capacity would not be
correct. Actually, one could write more about the traffic engineering aspects
of GDR selection, e.g., whether it is realistic that traffic distribution is
really equal. Yet, given that there seems to be only one implementation
according to the shepherd write-up, just changing the term may be sufficient.