[trill] Genart last call review of draft-ietf-trill-rbridge-multilevel-06

Stewart Bryant <stewart.bryant@gmail.com> Wed, 28 June 2017 18:06 UTC

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From: Stewart Bryant <stewart.bryant@gmail.com>
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Date: Wed, 28 Jun 2017 11:06:17 -0700
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Subject: [trill] Genart last call review of draft-ietf-trill-rbridge-multilevel-06
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Reviewer: Stewart Bryant
Review result: Ready

I am the assigned Gen-ART reviewer for this draft. The General Area
Review Team (Gen-ART) reviews all IETF documents being processed
by the IESG for the IETF Chair.  Please treat these comments just
like any other last call comments.

For more information, please see the FAQ at


Document: draft-ietf-trill-rbridge-multilevel-??
Reviewer: Stewart Bryant
Review Date: 2017-06-28
IETF LC End Date: 2017-06-28
IESG Telechat date: 2017-07-06


This is a well written document. I do however have a concern with the scaling
text in section 1.2.x, as I think this could be more accessible and ought to
include discussion of MAC Address scaling. More information below.

Major issues: None

Minor issues: The key justification for multi-area is scaling. The scene is set
in Section 1.2.x. However there are no references, the design size parameters
are not articulated for each case, and the equations are not derived. I think
that it would be helpful if the draft either provided some more explanation of
the scaling equations and the associated input assumptions, or provided the
assumptions and  directed the reader to an accessible text to understand the
equations. Although there is some discussion on it later there is no discussion
of the number of addresses to be learned in the single and multi-area cases and
the impact this has on the LSDB. The number of addresses to be learned will
impact the ingress RBridge FIB and the FIB update time so this is just as
significant in understanding the benefit of multi-level as understanding the
link-state convergence time is.

Nits/editorial comments: None