Last Call Review of draft-ietf-trill-rbridge-multilevel-06

Request Review of draft-ietf-trill-rbridge-multilevel
Requested rev. no specific revision (document currently at 07)
Type Last Call Review
Team General Area Review Team (Gen-ART) (genart)
Deadline 2017-06-28
Requested 2017-06-14
Authors Radia Perlman, Donald Eastlake, Mingui Zhang, Anoop Ghanwani, Hongjun Zhai
Draft last updated 2017-06-28
Completed reviews Rtgdir Early review of -01 by Stig Venaas (diff)
Genart Last Call review of -06 by Stewart Bryant (diff)
Opsdir Last Call review of -06 by Will LIU (diff)
Assignment Reviewer Stewart Bryant 
State Completed
Review review-ietf-trill-rbridge-multilevel-06-genart-lc-bryant-2017-06-28
Reviewed rev. 06 (document currently at 07)
Review result Ready
Review completed: 2017-06-28


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
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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