Shepherd writeup

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?

=> Proposed Standard. This document specifies the behaviour of a stateful
   encoder/decoder and fragmenter/defragmenter for extreme types of ioT links.
   The type is correctly indicated in the document.

(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

   This document defines the Static Context Header Compression (SCHC)
   framework, which provides both header compression and fragmentation
   functionalities.  SCHC has been tailored for Low Power Wide Area
   Networks (LPWAN).

   SCHC compression is based on a common static context stored in both
   the LPWAN devices and the network side.  This document defines a
   header compression mechanism and its application to compress IPv6/UDP

   This document also specifies a fragmentation and reassembly mechanism
   that is used to support the IPv6 MTU requirement over the LPWAN
   technologies.  Fragmentation is needed for IPv6 datagrams that, after
   SCHC compression or when such compression was not possible, still
   exceed the layer two maximum payload size.

   The SCHC header compression and fragmentation mechanisms are
   independent of the specific LPWAN technology over which they are
   used.  Note that this document defines generic functionalities and
   advisedly offers flexibility with regard to parameter settings and
   mechanism choices.  Such settings and choices are expected to be made
   in other technology-specific documents.

Working Group Summary

  There was nothing rough about it. The WGLC comments were rich but did not show
  fundamental issues in the design. The 30 open tickets lead mostly to editorial
  changes that helped clarify the text ann avoid misinterpretation. We spent the
  last IETF meeting and multiple interim going through the tickets and addressed
  them consensually. 

Document Quality
  The protocol was implemented and demonstrated over LoRa and SigFox
  technologies. There is only one vendor proposing a stack at this point.
  The reviewers are acknowledged in the document. The original
  shepherd was Dominique Barthel. He went so deep in the process, proposing
  edits and helping with the corrected text, that the chairs asked him to move
  to a co-author position, and took over shepherding, not because he was not
  good enough, but because he did too well at it.


  Document Shepherd: Pascal Thubert
  Responsible Area Director: Suresh Krishnan 
(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 shepherd performed 2 reviews, one at WGLC time, and one on version 16 
  which was pubished after WGLC comments wer all addressed. Considering the
  extent of the edition work, the chairs asked for a second WGLC, extending
  the WGLC to 3 weeks till the LPWAN meeting at IETF 102.

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

=> No doubt. This was implemented by a team working together and layed with at 
   IETF hackathons.


(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.

  The one element that may trigget discussion is the UDP checksum. This document
  emulates RFC 6282 and an implementation may elide the UDP checkum if a better
  protection such as a Message Inergety check of a same or larger size protects
  the compressed form of the UDP pseudo header and data.

(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.

  The shepherd is perfectly happy with the document as it stands. Note that 
  additional work is pending to adapt this to particular technologies, as well
  as to compress CoAP and other upper layer protocols.

(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

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

=> 	No IPR disclosures have been submitted directly on 
	No IPR disclosures have been submitted directly on 

(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?   

=> It is mostly the former, but there was a large working group following.

(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 conflict

(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

=> No nit on version 16

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

=> No such required formal review

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

=> Yes

(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?

=> No such case

(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. 

=> None

(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 such case

(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).

=> No IANA requirement

(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.

=> No IANA requirement

(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 case