Early Review of draft-ietf-mpls-mldp-in-band-wildcard-encoding-01

Request Review of draft-ietf-mpls-mldp-in-band-wildcard-encoding
Requested rev. no specific revision (document currently at 03)
Type Early Review
Team Routing Area Directorate (rtgdir)
Deadline 2014-11-23
Requested 2014-08-05
Authors IJsbrand Wijnands, Eric Rosen, Arkadiy Gulko, Uwe Joorde, Jeff Tantsura
Draft last updated 2014-08-14
Completed reviews Genart Last Call review of -02 by Elwyn Davies (diff)
Genart Last Call review of -02 by Elwyn Davies (diff)
Secdir Last Call review of -02 by Ólafur Guðmundsson (diff)
Rtgdir Early review of -01 by Lizhong Jin (diff)
Assignment Reviewer Lizhong Jin
State Completed
Review review-ietf-mpls-mldp-in-band-wildcard-encoding-01-rtgdir-early-jin-2014-08-14
Reviewed rev. 01 (document currently at 03)
Review result Ready
Review completed: 2014-08-14



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.




mLDP In-Band Signaling with Wildcards


Reviewer: Lizhong Jin

Review Date: Aug. 8, 2014.

IETF LC End Date: Aug. 8, 2014.

Intended Status: Standards Track


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


Before WG draft adoption, I also reviewed this draft as MPLS RT review. This draft solves a real problem, and it is easy to read and understand. I only have some minor concerns and some editorial issues. 

Major Issues:


Minor Issues:


Section 1

When an MP-LSP is being set up, the procedures of [RFC6826] and

   [I-D.ietf-l3vpn-mldp-vrf-in-band-signaling] , known as "mLDP In-Band

   Signaling", allow the Egress LSRs of the MP-LSP to encode the

   identifier of an IP multicast tree in the "Opaque Value" field of the

   mLDP FEC Element that identifies the MP-LSP.

[Lizhong] The reference [I-D.ietf-l3vpn-mldp-vrf-in-band-signaling] should be moved to the next section, right? This section is talking about RFC6826.

Section 3.2

Please note that, as always, the structure of the Opaque

   Value TLVs does not actually affect the operation of mLDP, but only

   affects the interface between mLDP and IP multicast at the Ingress 


[Lizhong] the interface between mLDP and IP multicast at the egress LSR is also affected. So it is better to say "...at the Ingress and Egress LSR".

Section 3.2

   Note that the Bidir TLVs do not have a "Source Address" sub-field,

   and hence the notion of a wildcard source is not applicable to them.

[Lizhong] since Bidir TLV is out of the scope, then it is not necessary to have the above note.

Section 3.3

However, if an Ingress LSR supports

   [RFC6826] and/or [I-D.ietf-l3vpn-mldp-vrf-in-band-signaling], but

   does not support this document, it has no choice but to treat any

   such received FEC elements as invalid; the procedures specified in

   [RFC6826] and [I-D.ietf-l3vpn-mldp-vrf-in-band-signaling] do not work

   when the Opaque values contain zeroes in the Source Address or Group

   Address sub-fields.

[Lizhong] I went throught RFC6826 and RFC7246, there is no definition of "zeroes". Then the above statement will be treated as an update to RFC6826 and RFC7246. If that is true, then the draft header needs to indicate that update.

Section 5.

If PIM is not enabled for the identified group, the Ingress LSR 

       acts as if it had received a (*,G) IGMP/MLD report from a

       downstream node, and the procedures as defined in [RFC4605] are



It seems the dataplane processing is missing here. E.g., add something like, the ingress LSR should forward the specified multicast stream to the downstream node through the MP-LSP identified by 

the Opaque Value TLV. That is not described in RFC4605.


Section 1.


Section 1 is a bit too long, and include both introduction and problem statement. It is suggested to separate two sections. But I will not object if you want to keep it. 

Section 4.2





Lizhong Jin