Shepherd writeup

    The MPLS working group request that:

                 Use of Multipath with MPLS and MPLS-TP

   Is published as an Informational RFC

As required by RFC 4858, this is the current template for the Document 
Shepherd Write-Up.

Changes are expected over time. This version is dated 24 February 2012.

(1) What type of RFC is being requested (BCP, Proposed Standard,
Internet Standard, Informational, Experimental, or Historic)?  Why
is this the proper type of RFC?  Is this type of RFC indicated in the
title page header?

    The requested type of RFC is Informational. This document does not
    specify any protocol or mechanisms, but discusses some mechanisms
    we have, how they have been used and gives recommendations on 
    how they could and should be used.

    The type of RFC is clearly indicated in the document header.

(2) The IESG approval announcement includes a Document Announcement
Write-Up. Please provide such a Document Announcement Write-Up. Recent
examples can be found in the "Action" announcements for approved
documents. The approval announcement contains the following sections:

Technical Summary

  Relevant content can frequently be found in the abstract 
  and/or introduction of the document. If not, this may be 
  an indication that there are deficiencies in the abstract 
  or introduction.

   Many MPLS implementations have supported multipath techniques and
   many MPLS deployments have used multipath techniques, particularly in
   very high bandwidth applications, such as provider IP/MPLS core
   networks.  MPLS-TP has strongly discouraged the use of multipath
   techniques.  Some degradation of MPLS-TP OAM performance cannot be
   avoided when operating over many types of multipath implementations.

   Using MPLS Entropy label, MPLS Label Switched Paths (LSPs) can be
   carried over multipath links while also providing a fully MPLS-TP
   compliant server layer for MPLS-TP LSPs.  This document describes the
   means of supporting MPLS as a server layer for MPLS-TP.  The use of
   MPLS-TP LSPs as a server layer for MPLS LSPs is also discussed.

Working Group Summary

  Was there anything in WG process that is worth noting? For 
  example, was there controversy about particular points or 
  were there decisions where the consensus was particularly 

   Nothing in particular to note, no controversies and the working is solidlybehind this document.

Document Quality

  Are there existing implementations of the protocol? Have a 
  significant number of vendors indicated their plan to 
  implement the specification? Are there any reviewers that 
  merit special mention as having done a thorough review, 
  e.g., one that resulted in important changes or a 
  conclusion that the document had no substantive issues? If 
  there was a MIB Doctor, Media Type or other expert review, 
  what was its course (briefly)? In the case of a Media Type 
  review, on what date was the request posted?

    This is an Informational document that has been well reviewed in the
    working, but not external reviews have been necessary.

    As part of the working group reviews it has also been reviewed by 
    the MPLS review team (MPLS-RT) prior to adoption as a working 
    group document.

    No specific implementation review has been done on this 
    document since we don't expect any direct vendor implementations
    of the document; instead the document discusses how the mechanisms
    that have been implemented can  be use. We know of operators
    that has deployed the techniques discussed in the document. 

   The MPLS-RT reviewers has been Mach Chen, Markus Jork, David Allan
   and Carlos Pignataro.


  Who is the Document Shepherd? Who is the Responsible Area

    Loa Andersson is the Document Shepherd
    Adrian Farrel is the Responsible Area Director

(3) Briefly describe the review of this document that was performed by
the Document Shepherd.  If this version of the document is not ready
for publication, please explain why the document is being forwarded to
the IESG.

    The Document Shepherd has reviewed the document in full three
    times, prior to that the document were accepted as a working group
    document, in preparation for working group last cal and the updated 
    document after working group last call.

(4) Does the document Shepherd have any concerns about the depth or
breadth of the reviews that have been performed?  

    No such concerns

(5) Do portions of the document need review from a particular or from
broader perspective, e.g., security, operational complexity, AAA, DNS,
DHCP, XML, or internationalization? If so, describe the review that
took place.

     No such reviews are necessary.

(6) Describe any specific concerns or issues that the Document Shepherd
has with this document that the Responsible Area Director and/or the
IESG should be aware of? For example, perhaps he or she is uncomfortable
with certain parts of the document, or has concerns whether there really
is a need for it. In any event, if the WG has discussed those issues and
has indicated that it still wishes to advance the document, detail those
concerns here.

    No such concerns.
    The working group is behind this document.

(7) Has each author confirmed that any and all appropriate IPR
disclosures required for full conformance with the provisions of BCP 78
and BCP 79 have already been filed. If not, explain why.

    The author has stated that he is unaware of any IPRs related to this

(8) Has an IPR disclosure been filed that references this document?
If so, summarize any WG discussion and conclusion regarding the IPR

    No IPRs has been filed against this document.

    The data-tracker list one potential IPR; however this  is not correct.
    This document in a very wide sense "replaced" an earlier document that
    addressed the same issues. This document is not a direct successor of
    the earlier document but has been re-worked in such away that the IPR
    disclosure is no relevant for this document. The party that filed the first
    IPR has not re-disclosed for this document. 

(9) How solid is the WG consensus behind this document? Does it 
represent the strong concurrence of a few individuals, with others
being silent, or does the WG as a whole understand and agree with it? 

    This document is pretty much mainstream MPLS, and there is a
    very good support for the document.  

(10) Has anyone threatened an appeal or otherwise indicated extreme 
discontent? If so, please summarise the areas of conflict in separate
email messages to the Responsible Area Director. (It should be in a
separate email because this questionnaire is publicly available.) 

    No such threats.

(11) Identify any ID nits the Document Shepherd has found in this
document. (See and the Internet-Drafts
Checklist). Boilerplate checks are not enough; this check needs to be

    The nits tool says that this document use RFC 2119 language, but does
    not have a reference to RFC 2119. The reference is in the document.
    The nits tool also correctly says that "MAY NOT" is not RFC 2119 
    language; this will be updated to proper RFC 2119 language if a 
    revised ID is needed for other reasons of through an RFC Editors note.

(12) Describe how the document meets any required formal review
criteria, such as the MIB Doctor, media type, and URI type reviews.

    No formal review needed.

(13) Have all references within this document been identified as
either normative or informative?

    Yes - all the references has been correctly identified.

(14) Are there normative references to documents that are not ready for
advancement or are otherwise in an unclear state? If such normative
references exist, what is the plan for their completion?

    All normative references are to existing RFCs.

(15) Are there downward normative references references (see RFC 3967)?
If so, list these downward references to support the Area Director in 
the Last Call procedure. 

    No downward references.

(16) Will publication of this document change the status of any
existing RFCs? Are those RFCs listed on the title page header, listed
in the abstract, and discussed in the introduction? If the RFCs are not
listed in the Abstract and Introduction, explain why, and point to the
part of the document where the relationship of this document to the
other RFCs is discussed. If this information is not in the document,
explain why the WG considers it unnecessary.

    No other RFC will be changed when this document is published.

(17) Describe the Document Shepherd's review of the IANA considerations
section, especially with regard to its consistency with the body of the
document. Confirm that all protocol extensions that the document makes
are associated with the appropriate reservations in IANA registries.
Confirm that any referenced IANA registries have been clearly
identified. Confirm that newly created IANA registries include a
detailed specification of the initial contents for the registry, that
allocations procedures for future registrations are defined, and a
reasonable name for the new registry has been suggested (see RFC 5226).

    This document include no request for IANA actions.

(18) List any new IANA registries that require Expert Review for future
allocations. Provide any public guidance that the IESG would find
useful in selecting the IANA Experts for these new registries.

    There are no new registries that require expert review.

(19) Describe reviews and automated checks performed by the Document
Shepherd to validate sections of the document written in a formal
language, such as XML code, BNF rules, MIB definitions, etc.

    No such automated checks necessary.