Shepherd writeup
rfc7788-10

As required by RFC 4858, this is the current template for the Document 
Shepherd Write-Up.

Please try and keep answers in regular type, and original questions in italics.

(1) What type of RFC is being requested (BCP, Proposed Standard,
Internet Standard, Informational, Experimental, or Historic)?  

Proposed Standard.

Why is this the proper type of RFC?  

HNCP is a protocol specification for configuration of a home network interacting with other standard track protocols such as DHCP, IPv6, DNS, etc. Two interoperable and independent implementations are known. 

Is this type of RFC indicated in the title page header?

Yes, the type of RFC is indicated in the title page header.

(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.

This document describes the Home Networking Control Protocol (HNCP), an extensible distributed configuration protocol for “unmanaged” (e.g., functions that are not configured manually or by a central management server of some kind) home network devices. The intent is to provide a distributed protocol for flooding of basic configuration state essential to IP network functionality. 

HNCP is described as a profile of and extension to the Distributed Node Consensus Protocol (DNCP).  HNCP enables discovery of network topology and borders, automated configuration of addresses (using the algorithm defined in draft-ietf-homenet-prefix-assignment-08), name resolution, and service discovery. 

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?

The earliest roots of HNCP are in draft-acee-ospf-ospfv3-autoconfig-00 (Oct 2011) which was eventually published as Standards Track RFC 7503,  with the expectation that other documents would define HOMENET-specific TLVs to be carried inside OSPFv3.

Strong resistance from the WG (as well as open source router software developers) to this tight coupling between a specific routing protocol and network configuration led to the split of HNCP as a standalone protocol first defined in draft-stenberg-homenet-hncp-00.

Later, DNCP (generic aspects of HNCP concerning synchronization of state among a set of nodes using Trickle[RFC6206]) were split from the main HNCP document to allow for modularity and potential reuse. After this final split, the HNCP document describes the HOMENET-specific TLVs and the DNCP profile used to synchronize them across the home network. 

Document Quality

  Are there existing implementations of the protocol? 

The reference “hnetd” implementation is at https://github.com/sbyx/hnetd/ (project homepage at http://www.homewrt.org/doku.php). 

There is a second (fully independent and interoperable) implementation available at https://github.com/jech/shncpd developed entirely from the specification documents without referal to the reference implementation.

There is a partial third implementation, though not fully independent, available here: https://github.com/fingon/pysyma


  Have a significant number of vendors indicated their plan to 
  implement the specification? 


The reference implementation has been a part of routing feed of OpenWrt since Barrier Breaker (14.07) release in July, 2014.

Google Nest, Comcast Xfinity, D-Link, Freebox, Technicolor, and Cisco have all expressed interest in implementing and/or shipping HNCP. HNCP is referenced in version 1.0 of the Thread Specification (Nest, Samsung, etc.)

“Homenet” running either the early OSPF version and later HNCP (with DNCP) has been demonstrated publicly at 9 IETF BnB events (every BnB since BnB began, plus at least one “pre BnB” event), HNCP split off from OSPF has been demontrated at the last 5 IETF BnB events. In addition to IETF, Homenet Implementations have been presented at:

3 IPv6 World Congress events in Paris
1 CES Event in Las Vegas
1 Cablelabs Meeting in Denver, Co

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?

Thomas Clausen provided an exhaustive review on behalf of Routing Area resulting in a number of changes to the document. Review (and coding effort) by Juliusz Chroboczek indicated that a second interoperable implementation was doable, and he provided only some minor clarifications that were incorporated later on. A number of other people have also reviewed the document. 

Personnel

  Who is the Document Shepherd? 

Mark Townsley

  Who is the Responsible Area Director?

Terry Manderson

(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 document shepherd reviewed the document, and comments of other reviewers, in particular one independent implementor who provided excellent review comments which have been incorporated. While not a work of Shakespeare, this is the working document upon which multiple independent interoperable implementations have now been based. 

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

No.

(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 working group (mailing list) seems to have diverging views on how distributed DNS in a home network should be handled; there has been no explicit criticism of the design within the document, but there seem to be alternatives (e.g. TSIG-based centralized server with proxied or host-sourced updates).

(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.

Modularization of DNCP from HNCP led to readabiliity and scope issues by some reviewers, in particular those reading DNCP alone with no background as to its origin. As such, it may be beneficial to advance the two as a cluster. 

(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
disclosures.

No.

(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 overall design seems to be approved by majority; some details (e.g. choice of routing protocol to use) seemed unsolvable and were left outside the document.

(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.) 

TBD

(11) Identify any ID nits the Document Shepherd has found in this
document. (See https://www.ietf.org/tools/idnits/ and the Internet-Drafts
Checklist). Boilerplate checks are not enough; this check needs to be
thorough.

No Nits.

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

N/A

(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?

Prefix assignment RFC reference refers to the old draft; the document is in RFC Editor queue.

(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. 

No downward normative references.


(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 status changes indicated.

(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).

Document requests one IANA registry for TLV-types with action “RFC required”,
initial contents and policies are given. Furthermore allocation of two UDP ports and a well-known IPv6 link-local multicast group are requested, the purpose of the allocation is mentioned.

(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 registries with “Expert Review” requested. Only requested IANA registry has policy “RFC Required”.

(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.

There is no formal language used in this document.

Back