[mpls] RtgDir review: draft-ietf-mpls-targeted-mldp-03.txt

[Lizhong Jin <[e-mail]>]

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. The purpose of
the review is to provide assistance to the Routing ADs. For more
information about the Routing Directorate, please see
http://www.ietf.org/iesg/directorate/routing.html

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-mpls-targeted-mldp-03.txt
Reviewer: Lizhong Jin
Review Date: 2 September 2013
IETF LC End Date: 05 September 2013
Intended Status: Standards Track

o Summary:
I have some minor concerns about this document that I think should be
resolved before publication.

o Comments:
This document provides the specification for using the LDP P2MP/MP2MP
extensions over a Targeted LDP session. It is clearly written. I only have
some minor issues which need to be clarified.

o Major Issues:
No major issues found.

o Minor Issues:

1. Section 1 is introduction, but section 1.2, 1.3, 1.4 seem to define the
specification, not overview introduction. It is suggest to have a separate
section to describe the introduction.
2. Section 1.1, the reference of mLDP RFC is indexed by [mLDP], not
[RFC6388] (same for [LDP-UP]). I am not quite sure IETF template allows
this, please check.
3. Section 1.2.1, line 176, what if there is IGP neighbors, and there is
targeted LDP session between U and D? This is possible in some deployments.
4. Section 1.2.1, line 188, is there a precedence among the different
methods, and the operator could define the precedence?
5. Section 3, line 356, how does D know to send label request, not label
mapping message? Multicast or unicast from U to D is determined by U, and D
could not get this information automatically. Then is there any static
configuration required here?
 6. Section 3, line 358, the label request messages mentioned in the text
should be upstream label request message. It is better to explicit to say
this.
 7. Section 3, line 382, it is said: While it is possible to do this, it is
highly RECOMMENDED that MP2MP LSPs be tunneled through MP2MP LSPs. I do not
quite understand this statement. This specification does not describe the
mechanism of MP2MP LSPs being tunneled through MP2MP LSPs. From my view,
MP2MP LSPs over MP2MP LSPs is not easy, and should resolve the upstream
label uniqueness among different upstream nodes. It should be caution to
have this recommendations here.

Regards
Lizhong