Last Call Review of draft-ietf-bfd-rfc5884-clarifications-02

Request Review of draft-ietf-bfd-rfc5884-clarifications
Requested rev. no specific revision (document currently at 04)
Type Last Call Review
Team Ops Directorate (opsdir)
Deadline 2015-10-13
Requested 2015-09-28
Authors Vengada Prasad Govindan, Kalyani Rajaraman, Greg Mirsky, Nobo Akiya, Sam Aldrin
Draft last updated 2015-10-19
Completed reviews Genart Telechat review of -03 by Christer Holmberg (diff)
Secdir Last Call review of -02 by Stephen Kent (diff)
Opsdir Last Call review of -02 by Scott Bradner (diff)
Assignment Reviewer Scott Bradner 
State Completed
Review review-ietf-bfd-rfc5884-clarifications-02-opsdir-lc-bradner-2015-10-19
Reviewed rev. 02 (document currently at 04)
Review result Ready
Review completed: 2015-10-19


I have done a OPS-DIR review of "Clarifications to RFC 5884” <draft-ietf-bfd-rfc5884-clarifications-03.txt>

summary - ready for publication

This document clarifies how best to operate multiple BFD (Bidirectional Forwarding Detection) sessions in MPLS environments.  
Any document that purports to clarify operational procedures is, by definition, a good thing when it comes
to operational impact, assuming the document is clear and makes sense.  This document is clear and makes sense.

One suggestion though.
The first observation in Section 2.3 says:

      The BFD session MAY be removed in the egress LSR if the BFD
      session transitions from UP to DOWN.  This can be done after the
      expiry of a configurable timer started after the BFD session state
      transitions from UP to DOWN at the egress LSR.

It might be helpful to specifically say what the aim of using such a timer is.  My guess is that the 
timer is used to introduce hysteresis to reduce flapping - but it would nice to say one way or the other