Last Call Review of draft-ietf-spring-segment-routing-ldp-interop-11
review-ietf-spring-segment-routing-ldp-interop-11-rtgdir-lc-takeda-2018-05-27-00

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-spring-segment-routing-ldp-interop-11
 Reviewer: Tomonori Takeda
 Review Date: May 26th, 2018
 IETF LC End Date: Not known
 Intended Status: Standards Track

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

Major Issues:
None

Minor Issues:
I am a little bit confused about the relationship of SR/LDP interworking and
migration from LDP to SR.

The document says:

   "This document outlines the mechanisms through which SR interworks
   with LDP in cases where a mix of SR-capable and non-SR-capable
   routers co- exist within the same network and more precisely in the
   same routing domain."

My understanding of SR/LDP interworking and migration from LDP to SR is a
different story. Migration from LDP to SR may or may not use SR/LDP
interworking.

Section 3 described migration from LDP to SR, but this migration scenario does
not use SR/LDP interworking (expect for SR-based FRR usage to protect LDP
traffic). This migration scenario uses SR/LDP co-existence, though.

Is section 3 for information purpose only?

Nits:
None

Thanks,
Tomonori Takeda