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Shepherd writeup

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?

PS - This is a standards track specification. It describes the protocol
extensions needed for the SCTP endpoints and the mechanisms for NAT functions
necessary to provide similar features of NAPT in the single point and
multipoint traversal scenario.

(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:

The Stream Control Transmission Protocol (SCTP) provides a reliable
communications channel between two end-hosts in many ways similar to the
Transmission Control Protocol (TCP). With the widespread deployment of Network
Address Translators (NAT), specialized code has been added to NAT functions for
TCP that allows multiple hosts to reside behind a NAT function and yet share a
single IPv4 address, even when two hosts (behind a NAT function) choose the
same port numbers for their connection.

Working Group Summary:

This document started life as draft-stewart-behave-sctpnat in 2005, and was
later added to the behave WG charter in 2013.. TSVWG inherited the work of the
former behave WG when this concluded.  draft-stewart-natsupp-tsvwg was brought
to tsvwg and adopted in 2010.

The ID completes a series of specifications that specify how core IETF
transports interact with NAT.  This work item was developed, but in 2015 the
specifications were rewritten to follow the current approach. The document was
also restructured to more clearly separate the text for endpoint implementors
and SCTP transport maintainers. In 2018, there was a discussion in the WG about
whether to continue work on legacy support for NAT, and the working group
concluded that this document should be published, and this was still in
charter. The WG finally decided to add  a yang model, which was developed
separately and added to this spec in revision 16, in 2020. The WG is pleased
that this long cycle of development has finally resulted in a complete and
useful spec!

Document Quality:

This document has been reviewed in multiple rounds by the working group. It
represents the current consensus of this WG.

A YANG Doctor review, has been completed (draft-ietf-tsvwg-natsupp-16) and the
document was updated after finalising this model.

Gorry Fairhurst is the Document Shepherd
Magnus Westerlund 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.

This document has completed review by the TSVWG and is considered ready for
publication. The draft was updated following experience: FreeBSD contains the
middlebox implementation based on an older version.

(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.


(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.

RFCs published by the TSVWG can contain informative as well as normative
sections. This is the case for many of the SCTP specifications, including this

(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, no IPR is known - Irene, Michael, Randall.

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

No IPR disclosures were observed for this or its predecessor drafts.

(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 TSVWG LC progressed to a clear outcome. Issues were raised by interested
parties and these were resolved post-WGLC. There is a consensus to publish this

(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.


Note this is about NAT, and therefore there are instances of lines with private
range IPv4 addresses. The document is IPv4 only.

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

Yang review done (rev-16).

(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?


(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


(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.


(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 8126).

IANA updates are noted.

(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.

None - it refers to existing SCTP registries.

(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, YANG modules, etc.

Yang review done.

(20) If the document contains a YANG module, has the module been checked with
any of the recommended validation tools
( for syntax and
formatting validation? If there are any resulting errors or warnings, what is
the justification for not fixing them at this time? Does the YANG module comply
with the Network Management Datastore Architecture (NMDA) as specified in