Early Review of draft-ietf-softwire-unified-cpe-04
review-ietf-softwire-unified-cpe-04-rtgdir-early-scudder-2016-08-16-00

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-softwire-unified-cpe-04
Reviewer: John Scudder
Review Date:  August 16, 2016
IETF LC End Date:  August 25, 2016
Intended Status: Standards Track

Summary:

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

Comments:

The draft is well-written, clear, readable and concise without being terse. As
a nonexpert, I felt it provided sufficient explanation and context for me to
understand without having to spend a great deal of time chasing references.

Major Issues:

No major issues found.

Minor Issues:

Section 1.3 says:

   4.  When a match is found, the client SHOULD configure the resulting
       S46 mechanism.  Configuration for other S46 mechanisms MUST be
       discarded.

It was not obvious to me why the SHOULD is not a MUST. Under what circumstances
would it be valid for an implementer to disregard the SHOULD? I find it is
often a helpful exercise to explain such exceptions in a MAY clause. If there
are no exceptions, then it's a MUST.

Nits:

-  You use the term "BR/AFTR" but don't define what BR means. A definition
would help. (AFTR is defined in section 1.)

-  Likewise you haven't defined "CE". It's a pretty common term, but I would
think it still needs a definition, or better still you could rewrite to remove
the acronym (you only use it once).

- Likewise "DHCPv6 ORO message". It's reasonably obvious from context, and not
difficult to look up, but would still benefit from being expanded in line
instead of using the acronym.