Subject: [bess] Rtgdir last call review of draft-ietf-bess-vpls-multihoming-05

From: Ben Niven-Jenkins via Datatracker <[email-masked]>
Date: Mon, 09 Mar 2020 10:56:08 -0700

Reviewer: Ben Niven-Jenkins
Review result: Has Nits

 Hello,

I have been selected as the Routing Directorate reviewer for this draft. The
Routing Directorate seeks to review all routing or routing-related drafts as
they pass through IETF last call and IESG review, and sometimes on special
request. The purpose of the review is to provide assistance to the Routing ADs.
For more information about the Routing Directorate, please see
​http://trac.tools.ietf.org/area/rtg/trac/wiki/RtgDir

Although these comments are primarily for the use of the Routing ADs, it would
be helpful if you could consider them along with any other IETF Last Call
comments that you receive, and strive to resolve them through discussion or by
updating the draft.

Document: draft-ietf-bess-vpls-multihoming-05.txt
Reviewer: Ben Niven-Jenkins
Review Date: 9th March 2020
IETF LC End Date: 12th March 2020
Intended Status: Standards Track

Summary: This document is basically ready for publication, but has nits that
should be considered prior to publication.

Comments: This document is readable and presents an easy to follow solution to
a complex problem.

Major Issues: No major issues found.

Minor issues:
Section 3.2 - Deployment Considerations. “Note that a CE-ID=0 is invalid and a
PE should discard such an advertisement.” Is that really a SHOULD (or a MUST)?

Section 3.3.2.1 - RD. “Actual process of assigning Route Distinguisher values
must guarantee its uniqueness per PE node.” Is that really a MUST?

Section 6.1 - BGP based VPLS. “For compatibility with PEs that use multiple
VE-IDs with non-zero label block values for multi-homing operation, it is a
requirement that a PE receiving such advertisements must use the labels in the
NLRIs associated with lowest VE-ID for PW creation.” Is that really a MUST?

Nits:
Section 1 - Introduction introduces the abbreviation BGP MH without expanding
it on first use. As this is the only place in the document where the
abbreviation BGP MH is used, I would suggest just expanding it in the
introduction, i.e. s/BGP MH/BGP multi-homing/

Section 1.1 - General Terminology. You repeat the same two sentences at the end
of paragraph 3 that also constitute paragraph 4: ‘A VPLS site is a grouping of
ports on a PE that belong to the same VPLS domain.  The terms "VPLS instance"
and "VPLS domain" are used interchangeably in this document.’. Remove one of
the sets of repeated sentences.

Section 1.1 - General Terminology, paragraph 5. You say that “VPLS site” and
“CE site” are used interchangeably but the definition of VPLS site doesn’t
mention CEs and “CE site” implies (to me) the site of a particular CE device
which isn’t exactly the same as a “VPLS site” as defined by the document. As
there are only 2 instances of “CE site” in the document (outside of where you
say it is used interchangeably with “VPLS site”), you may want to consider just
replacing those 3 instances with “VPLS site” and removing the sentence stating
“VPLS site” and “CE site” are interchangeable in section 1.1.

Section 1.1 - General Terminology, paragraph 6. s/and label base is called as
VE NLRI/and label base is called a VE NLRI/  (i.e. swap “as” for “a”

Section 1.1 - General Terminology, paragraphs 7 & 8. s/Section Section
3.1/Section 3.1/

Section 3.3.3 - Election Procedures. s/specific to designated forwarded
election procedures/specific to designated forwarder election procedures/

Section 3.5 - Pseudowire and Site-ID Binding Properties. The first sentence is
very difficult to parse. I think what you are trying to say is something like
“For the use case where a single PE provides connectivity to a set of CEs where
some CEs are multi-homed and others are not, only a single pseudowire MAY be
established.”

Section 3.5 - Pseudowire and Site-ID Binding Properties. s/PE3 would
establish/PE3 could establish/  (because using a single PW is optional as per
the earlier MAY)

Section 3.5 - Pseudowire and Site-ID Binding Properties. s/Since label
allocation and pseudowire established is tied to site-ID/Since label allocation
and pseudowire establishment is tied to site-ID/

Regards
Ben