Last Call Review of draft-ietf-rtgwg-bgp-pic-12
review-ietf-rtgwg-bgp-pic-12-tsvart-lc-trammell-2020-12-18-00

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
review as part of the last-call comments they receive. Please always CC
tsv-art@ietf.org if you reply to or forward this review.

Assuming the routing aspects of it are sound, this document is ready from a
transport standpoint.

This informational document describes an approach to speeding BGP convergence
utilizing multiple next-hops; if widely deployed, it would lead to an increased
prevalence of ECMP on interdomain paths during this convergence. It therefore
trades off more transport-visible reordering for faster convergence time.
However, given the prevalence of ECMP routing inside networks, transport
protocols must already tolerate this reordering, so the marginal impact on
transport of this proposal is minimal.