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Shepherd writeup

This is the Publication Request and document shepherd write-up for

UDP Checksum Complement in OWAMP and TWAMP

This questionnaire version is dated 24 February 2012.

Al Morton is the Document Shepherd, and prepared this form: April 2015.

(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?

Experimental, as indicated on the title page.
No changes to the protocol are required to use this option.

(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:

In many IP measurement protocols, timestamps are required to calculate
packet transfer delay, and these timestamps occupy fields above the IP
layer. When implementors prefer to avoid the delay of stack processing,
it is preferred to insert the timestamps as close to the network
interface as possible, but this also requires maintaining sanity
among checksums and other integrity checks.  This memo defines one way
to assign an optional field at the end of the UDP payload of test packets
to complement the timestamp and populate that field to keep checksum accuracy.

Working Group Summary:

There has been sufficient review during 2 years of development,
and the comments were both constructive and supportive of this simple idea.
The draft can serve a useful purpose for the industry.

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?

One chip vendor has implemented the procedure in the draft from a hardware
perspective, and another chip vendor has indicated their plans (privately)
to do the same.  There are no known HW and SW implementations with TWAMP or
OWAMP at this time.

As far as expert reviews, there was sufficient review from the community
of TWAMP experts.


Who is the Document Shepherd? Who is the Responsible Area Director?

Al Morton is Shepherd, Spencer Dawkins is AD.

(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.

I've reviewed this draft at WGLC. Nits check is now clean, except
for one line which is 8 characters too long.
All my comments have been addressed, and those of the WG have been addressed,

(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.

There is sufficient cross-participation between IPPM, BMWG, and TICTOC
to ensure broad review.

(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.


(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?

There is one related IPR disclosure by the author's company:

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

There is one IPR disclosure:

The WG was informed of the IPR on the list, and there were no comments in

(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 WG appears satisfied that this simple/valuable idea is
sufficiently described. The name of the feature was
changed to Checksum Complement from Checksum Trailer
based on WG feedback, and this appears suitable to all.

(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.

Nits check indicates one line is 8 characters too long.

(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?


(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 5226).

There are no IANA actions required, and the section can be deleted.

(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.


(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.