Last Call Review of draft-ietf-mpls-ldp-yang-06

Request Review of draft-ietf-mpls-ldp-yang-06
Requested rev. 06 (document currently at 07)
Type Last Call Review
Team Routing Area Directorate (rtgdir)
Deadline 2019-11-01
Requested 2019-09-13
Requested by Tarek Saad
Authors Kamran Raza, Rajiv Asati, Xufeng Liu, Santosh Esale, Xia Chen, Himanshu Shah
Draft last updated 2019-11-01
Completed reviews Yangdoctors Early review of -01 by Dean Bogdanović (diff)
Yangdoctors Early review of -02 by Jan Lindblad (diff)
Genart Last Call review of -06 by Theresa Enghardt (diff)
Rtgdir Last Call review of -06 by Yingzhen Qu (diff)
Yangdoctors Last Call review of -06 by Jan Lindblad (diff)
Secdir Telechat review of -07 by Shawn Emery
This document describes a YANG data model for Multi-Protocol Label Switching (MPLS) Label Distribution Protocol (LDP).
Assignment Reviewer Yingzhen Qu
State Completed
Review review-ietf-mpls-ldp-yang-06-rtgdir-lc-qu-2019-11-01
Posted at
Reviewed rev. 06 (document currently at 07)
Review result Has Issues
Review completed: 2019-11-01


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

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-ldp-yang
Reviewer: Yingzhen Qu
Review Date: Nov 1st, 2019
Intended Status: Standards Track


This document is near ready for publication. It has some issues that should be at least considered prior to publication.


Thanks for working on this draft. As an active YANG contributor I appreciate the work here.

Major issues:

I’m not sure whether this should be considered as a major issue, which is how the document is structured. The draft separates the configuration and operation states into two sections, and this seems to be a before NMDA product and a bit redundant to me. The tree structures are used in different ways multiple times in the document, and this significantly reduces the readability of the modules. 

Minor Issues:

I feel the English in this draft could be improved, but I’m not a native speaker. Maybe RFC editor will help with this?

It seems that “model” and “module” are used exchangeable in this document, please make them consistent.

“YANG” should be capital cased, and there are “yang” at multiple places in this document. Please fix them.

Please consider add names to figures.

I understand inheritance is an important feature of document. I’d suggest maybe add a section/paragraph in “overview” to introduce the concept and how it works instead of repeating the idea with examples in every major container design. 

Nits for your consideration:

Section 1.1 
Whereas, the "extended" category contains all other non-base features.
Please consider remove “all” because not all other features are covered.

Section 3
extended "ietf-mpls-ldp-extended" module that models the extended
      LDP features and augments the base LDP
Please consider removed “extended” at the beginning, and add “module” at the end, “augments the base LDP module”.

There are four main containers in our module(s):
I suppose you meant “four types of containers”?

Section 4
under LDP base and extended.
Please add a “module” at the end.

Section 5
Following is the high-level configuration organization for base LDP:
Please add a “module” at the end.

Typo in figure 3 “targeteted”

Typo in figure 4 “targeteted”

Given the configuration hierarchy, the model allows inheritance such
   that an item in a child tree is able to derive value from a similar
   or related item in one of the parent.
for grammar, it should be “one of the parents”, but this sentence is a bit confusing. I’d suggest add a bit more explanation how inheritance work.

Missing period “.” at the end of the first sentence.

The tree showing here is not a complete tree, just want to make sure whether this is intentional?

Missing period “.” at the end of the first sentence.
“LSR id” and “LSR Id” both are used here, please keep them consistent.
Missing “.” at the end of the first paragraph.

“A peer is uniquely identified using its
 LSR Id and hence LSR Id is the key for peer list”
Please consider simplify the sentence to “A peer is uniquely identified by its LSR Id.”

Section 6
“  Operational state of LDP can be queried and obtained from read-only
   state containers that fall under the same tree (/rt:routing/
   rt:control-plane-protocols/) as the configuration.”
This sentence is a bit confusing. Please consider revise it.