Document Shepherd Write-Up
(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 document presents the results of an implementation survey of
technology developed within the PWE3 WG. It
does not define any new protocol or recommend any particular design
or specifically impact interoperability. Informational is therefore appropriate.
This is indicated in the title page 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:
Most Pseudowire Emulation Edge-to-Edge (PWE3) encapsulations mandate
the use of the Control Word (CW) in order to better emulate the
services for which the encapsulations have been defined. However,
some encapsulations treat the Control Word as optional. As a result,
implementations of the CW, for encapsulations for which it is
optional, vary by equipment manufacturer, equipment model and service
provider network. Similarly, Virtual Circuit Connectivity
Verification (VCCV) supports three Control Channel (CC) types and
multiple Connectivity Verification (CV) Types. This flexibility has
led to reports of interoperability issues within deployed networks
and associated drafts to attempt to remedy the situation. This
survey of the PW/VCCV user community was conducted to determine
implementation trends. The survey and results is presented herein.
Working Group Summary
RFC5085 defines 3 VCCV channel types. These are essentially the mechanisms
for transport of the PW associated channel that is used to carry e.g. PW OAM
messages. In addition, RFC6423 adds a 4th mechanism which uses the GAL. There
is currently no clear definition of which modes are mandatory and which modes
are optional to implement. This has caused concerns by some participants in
the operator community that the proliferation of modes causes interoperability
issues between vendors. As a first step to rationalising the number of modes,
the WG conducted a survey to try to quantify which modes are in use today and so
determine which ones could be either deprecated, or made optional in a possible
future update to RFC5085. This draft contains the results of that survey. Since the
survey contains useful information pertaining to the current state of PW deployments,
there was consensus to record the results of the survey in an Informational RFC.
Note that the draft spent an extended amount of time in AD review while additional
editorial help was sought to address the comments from the AD. During this period the
draft went dormant. Additional editorial help was eventually found, and the draft progressed
as it was felt that the survey results contained therein were still relevant. The WG
has also been using these results as a basis for on-going work, and it was felt that a
permanent record of the results is desirable.
Note that the name of the document that was originally last called by the WG was
draft-ietf-pwe3-pw-vccv-impl-survey-results, but this was updated to
draft-ietf-pwe3-vccv-impl-survey-results as a result of a comment from
The document describes a service provider implementation survey, sampling the deployments
of PWs and their respective VCCV types. There is likely to be a skew in the results towards
operators that are willing to divulge details of their network deployments, and towards
those that participate in the IETF. However,
the results were anonymised, and a broad cross-section of both large and smaller
operators participated, which may help to mitigate any skew. I have no concerns
about the quality of the document.
The document does not specify any MIB changes or additions which would need review.
The document shepherd is Matthew Bocci.
The responsible Area Director is Stewart Bryant.
(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 document has been reviewed by the document shepherd and some minor
comments addressed. The document is now ready for forwarding to the IESG.
(4) Does the document Shepherd have any concerns about the depth or
breadth of the reviews that have been performed?
No. The document has received adequate review and was discussed over a
period of a number of IETFs.
(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
(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
(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.
Yes. The author has indicated that they are not aware of any IPR.
(8) Has an IPR disclosure been filed that references this document?
If so, summarize any WG discussion and conclusion regarding the IPR
(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?
The consensus behind this document is solid.
(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.)
(11) Identify any ID nits the Document Shepherd has found in this
document. (See http://www.ietf.org/tools/idnits/ and the Internet-Drafts
Checklist). Boilerplate checks are not enough; this check needs to be
There are no ID Nits issues.
(12) Describe how the document meets any required formal review
criteria, such as the MIB Doctor, media type, and URI type reviews.
There are no formal review criteria.
(13) Have all references within this document been identified as
either normative or informative?
(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?
There are no normative references.
(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.
There are no normative 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.
There are no changes proposed to the status of existing RFCs.
(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).
There are no IANA requests.
(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 IANA requests.
(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.
There are no sections of the document that use formal languages.