Re: [mpls] MPLS-RT review of draft-kompella-mpls-larp

Sriganesh Kini <> Thu, 16 July 2015 01:11 UTC

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From: Sriganesh Kini <>
To: Loa Andersson <>, Lucy yong <>, "Kamran Raza (skraza)" <>, "Aissaoui, Mustapha (Mustapha)" <>, "" <>, "" <>, "" <>
Thread-Topic: MPLS-RT review of draft-kompella-mpls-larp
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Date: Thu, 16 Jul 2015 01:11:26 +0000
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Subject: Re: [mpls] MPLS-RT review of draft-kompella-mpls-larp
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This is the MPLS-RT review of draft-kompella-mpls-larp -

The document is coherent.

Regarding whether it is useful (i.e., is it likely to be actually useful in operational networks), the yet to do be defined reference [TODO-MPLS-FABRIC] would be needed before commenting on it. Also if any host NIC vendors can chime in or any evidence of host operating systems that plan to support this is present, it will help to answer this question. I don't see any technical reason why MPLS shouldn't be useful in DC networks. 

The document is technically sound for most parts, but as sec 4 points out there are a number of issues still left. I would add a couple issues -
	1.	The restarts should address control-plane restart as well. Though there is no session between server and client, the action (if any) to be performed when control-plane restarts should be specified.

	2.	If a LSR (L-ARP server) goes down, then there should be a proposed resiliency mechanism (e.g. using BFD).

Other comments:
	1.	It would be very useful to list the use-cases where a host wants to participate in the fabric through a simpler mechanism than RSVP-TE UNI. Additionally, even though label distribution itself may become simpler using ARP, doesn't the host have to do other MPLS OAM functionality? Some discussion of this topic is needed.

	2.	Section 3.4 "... presence of a complex topology...". Which topology is this referring to ? Is it the underlying ethernet network topology ? Pls state it explicitly and also why it would cause a problem to LARP.

	1.	Section 1, page 1 s/Centre/Center

	2.	The node 'T' should be shown in the MPLS Fabric of Fig 1.

	3.	Missing reference [TODO-MPLS-FABRIC]

	4.	Sec 3.4 "Seamless MPLS" reference is missing.

Since [TODO-MPLS-FABRIC] seems to the primary driver for this document, it would be better to consider this for a WG document after that document is published.

- Sri
From: Loa Andersson []
Sent: Tuesday, 30 June 2015 9:18 AM
To: Lucy yong; Kamran Raza (skraza); Sriganesh Kini; Aissaoui, Mustapha (Mustapha);;
Subject: MPLS-RT review of draft-kompella-mpls-larp

Lucy, Kamran, Sri and Mustapha;

You have be selected as MPLS-RT reviewers for draft-kompella-mpls-larp.

Note to authors: You have been CC'd on this email so that you can know
that this review is going on. However, please do not review your own

Reviews should comment on whether the document is coherent, is it
useful (ie, is it likely to be actually useful in operational networks),
and is the document technically sound?

We are interested in knowing whether the document is ready to be
considered for WG adoption (ie, it doesn't have to be perfect at this
point, but should be a good start).

Reviews should be sent to the document authors, WG co-chairs and WG
secretary, and CC'd to the MPLS WG email list. If necessary, comments
may be sent privately to only the WG chairs.

If you have technical comments you should try to be explicit about what
needs to be resolved before adopting it as a working group document, and
what can wait until the document is a working group document and the
working group has the revision control.

Are you able to review this draft by 14, 2015? Please respond in a
timely fashion.

Thanks, Loa
(as MPLS WG chair)

Loa Andersson                        email:
Senior MPLS Expert                
Huawei Technologies (consultant)     phone: +46 739 81 21 64