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Shepherd writeup
rfc7251-08

(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?

<response to (1)>
i) Type of RFC Requested: Informational
ii) It is the proper type of RFC because it is essentially the same document as
RFC 5289 using a different AEAD algorithm (AES-CCM instead of AES-GCM) iii) The
type of RFC is indicated in the title page header </response to (1)>

(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:

Relevant content can frequently be found in the abstract and/or introduction of
the document. If not, this may be an indication that there are deficiencies in
the abstract or introduction.

<response to (2) Technical Summary>
The document describes the use of Advanced Encryption Standard (AES) in Counter
with CBC-MAC Mode (CCM) in several TLS ciphersuites. AES-CCM provides both
authentication and confidentiality and uses as its only primitive the AES
encrypt operation (the AES decrypt operation is not needed).  This makes it
amenable to compact implementations, which is advantageous in constrained
environments. The use of AES-CCM has been specified for IPsec ESP and 802.15.4
wireless networks. The document utilizes the AEAD facility within TLS 1.2
(RFC5246) and the AES-CCM-based AEAD algorithms defined in RFC5116 and RFC6655.
All of these algorithms use AES-CCM; some have shorter authentication tags, and
are therefore more suitable for use across networks in which bandwidth is
constrained and message sizes may be small. The ciphersuites defined in this
document use Ephemeral Elliptic Curve Diffie-Hellman (ECDHE) as their key
establishment mechanism; these ciphersuites can be used with DTLS (RFC6347).
</response to (2) Technical Summary>

Working Group Summary:

Was there anything in WG process that is worth noting? For example, was there
controversy about particular points or were there decisions where the consensus
was particularly rough?

<response to (2) Working Group Summary>
The document was proposed to the TLS working group. The TLS working group did
not believe it needed WG adoption and suggested publication as an individual
submission. It was suggested that the intended status be informational to bring
it inline with RCC 5289. There was some concern regarding adding yet more
ciphersuites for TLS however RFC 6655 was published which does set a precedent
for the use of AES-CCM-based ciphersuites. </response to (2) Working Group
Summary>

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?

<response to (2) Document Quality>
There are numerous existing implementations of the protocol as it is currently
being adopted and tested by ZigBee Alliance members involved in the development
of the ZigBee IP stack and Smart Energy Profile version 2 (SEP2). There are
currently 7 independent vendors implemeting the protocol for ZigBee IP and over
20 for SEP2. The ciphersuites are also specified for use with CoAP
(draft-ietf-core-coap) in conjunction with DTLS. </response to (2) Document
Quality>

Personnel:

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

<response to (2) Personnel>
The Document Shepherd is Robert Cragie. The Responsible Area Director is Sean
Turner. </response to (2) Personnel>

(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.

<response to (3)>
The Document Shepherd has reviewed the draft document and has been party to the
interoperability testing events undertaken by the vendors to confirm
interoperable implementation of the protocol and its fitness for purpose.
</response to (3)>

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

<response to (4)>
The document has been submitted for review on all relevant WG mailing lists and
has had discussion. It has also been through practical implementations subject
to continuous review by the implementors, who have fed back comments to the
authors, who have subsequently incorporated the comments into the latest draft.
</response to (4)>

(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.

<response to (5)>
As the protocol describes a ciphersuite security, the Document Shepherd
recommends the document is reviewed by the Security area. However, it is
fundamentally the same in function as RFC 5289 except for the different AEAD
ciphersuite. </response to (5)>

(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.

<response to (6)>
The Document Shepherd has not indicated any specific concerns or issues with
the document. The Responsible Area Director has raised concerns regarding the
section on MTI (mandatory-to-implement) curves and suggests removal of the
section or making it an informative annex. </response to (6)>

(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?

<response to (7)>
The authors have confirmed that all appropriate IPR disclosures required for
full conformance with BCP 78 and BCP 79. </response to (7)>

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

<response to (8)>
IPR disclosure #1443 and the IPR disclosures it updates have been filed that
references the document. These are inline with IPR disclosures filed for RFC
5289 (#1485 and the IPR disclosures it updates). </response to (8)>

(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?

<response to (9)>
The interested community as a whole understands and agrees with the document,
proven by implementation. </response to (9)>

(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.)

<response to (10)>
No.
</response to (10)>

(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 thorough.

<response to (11)>
There are no significant nits found from a verbose nits check of draft-06.
</response to (11)>

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

<response to (12)>
No formal review required.
</response to (12)>

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

<response to (13)>
Yes.
</response to (13)>

(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?

<response to (14)>
All normative references are in a clear state.
</response to (14)>

(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.

<response to (15)>
There are no downward normative references.
</response to (15)>

(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.

<response to (16)>
The publication of this document will not affect the status of any existing
RFCs. </response to (16)>

(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).

<response to (17)>
The IANA considerations section identifies the requirements of 4 additional
ciphersuites. </response to (17)>

(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.

<response to (18)>
There are no new IANA registries that require Expert Review for future
allocations. </response to (18)>

(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.

<response to (19)>
There are no parts of the document written in a formal language.
</response to (19)>
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