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Shepherd writeup

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 draft is intended to be at, and requests, Informational status.

(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

Technical Summary:

This document summarizes NAT64 function deployment scenarios and
operational experience.  Both NAT64 Carrier Grade NAT (NAT64-CGN) and
NAT64 server Front End (NAT64-FE) are considered in this document.

Working Group Summary:

The original discussion is derived from the presentation of Afterwards, it
was documented as draft-chen-v6ops-nat64-experience in Feb 2012. The
working group document is a report developed by several operators on
the use of a NAT64 between an IPv6-only mobile network and the larger
IPv4-only network.

The draft has been discussed at length and in detail. There are some
operators in the working group that have a problem with it because it
openly discusses the use of RFC 6052/6144-6147 IPv4/IPv6 translation
and RFC 4193 ULAs; they hold the viewpoint that translation and the
use of non-global address space is philosophically and operationally
problematic. For example, a matter dealt with in the draft in response
to working group discussion, it often sacrifices geolocation
information that is important to certain types of services. The
authors of the draft also point out that running a dual stack mobile
network is expensive for reasons specific to mobile networks, and view
the trade-offs as acceptable given the economics.

Document Quality:

As specified in the abstract, the document is not a protocol or
procedure; it is a report of operational deployment and testing of a
NAT64 service between an IPv6-only mobile network and the larger IPv4
Internet as well as a NAT64 service in an IDC environment. This
testing includes the use of NAT64 CGN and NAT64 FE, its coexistence
with more traditional NAT44, Reliability, Availability, and
Maintainability issues, the transparency or lack of it regarding
source addresses, Quality of Experience, MTU issues, and ULA-related


The document shepherd is Fred Baker. The responsible AD is Joel

(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.

In the view of the chairs, this document is ready for publication,
having been largely beaten up in the working group. The shepherd
tracked working group commentary, often discussing it privately with
the commentators or the authors, and sometimes publicly. The shepherd
also read the document and ran it through idnits.

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


(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. One could imagine the Operations Directorate getting involved, but
the document had detailed operational review in the working group.

(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.

I have no issues with the document as it stands.

(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 authors tell me that they know of no outstanding IPR disclosures.

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

=draft-ietf-v6ops-nat64-experience, there are no relevant 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?

As noted, there are some in the working group who have philosophical
differences with the authors regarding the service. It is probably
most fair to say that the strongest proponents of the service are
those that have deployed it or are contemplating doing so. This is a
fact of operational networks - they are not all deployed the same way,
and the proponents of various approaches tend to like their approaches
better than others for the reasons for which they chose them. As a
report on testing and operational experience, though, in the view of
the chairs and many of those who have commented on the list, the
report has operational and archival value.

(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 and the Internet-
(Drafts Checklist). Boilerplate checks are not enough; this check
(needs to be thorough.

idnits shows no issues. I didn't find other issues.

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


(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 is a normative reference to draft-ietf-appsawg-http-forwarded,
which is currently in IESG review.

(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.

The normative references are all to informational, BCP, or standards
track documents. As an informational document, these are not downward

(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.

The document doesn't change the status of any 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).

This memo includes no request to IANA, and says as much.

(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 none.

(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.

None. There is no formal language in the document.