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Shepherd writeup

# Document Shepherd Write-Up for Group Documents

Thank you for your service as a document shepherd. Among the responsibilities is
answering the questions in this write-up to give helpful context to Last Call
and Internet Engineering Steering Group ([IESG][1]) reviewers, and your
diligence in completing it is appreciated. The full role of the shepherd is
further described in [RFC 4858][2]. You will need the cooperation of the authors
and editors to complete these checks.

Note that some numbered items contain multiple related questions; please be sure
to answer all of them.

## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
   few individuals, with others being silent, or did it reach broad agreement?

Broad agreement. DNSSD has historically been a pretty small WG with a very small
number of vocal participants, but this draft is required for Matter (part of
CSA) and that brought in vocal participants and implementers. The draft in its
current shape represents the broad agreement of these folks.

2. Was there controversy about particular points, or were there decisions where
   the consensus was particularly rough?

None in the WG. Apple have used this since 2005 but didn't seek standardisation
at the time. They brought it to the WG at IETF111 as it's a component of SRP.
There was brief debate about whether it should sit in DNSSD. It was discussed
with DNSOP chairs and agreed to call for adoption into DNSSD. The adoption call
went to both groups, but there was no pushback.

3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
   so, please summarize 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.)


4. For protocol documents, are there existing implementations of the contents of
   the document? Have a significant number of potential implementers indicated
   plans to implement? Are any existing implementations reported somewhere,
   either in the document itself (as [RFC 7942][3] recommends) or elsewhere

We're aware of at least two implementations already in production or going into
production soon, with more to come after publication. It is a mandatory part of
the Matter spec, so implementations are likely to expand greatly over the next
few years.

## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
   IETF working groups or external organizations, and would it therefore benefit
   from their review? Have those reviews occurred? If yes, describe which
   reviews took place.

We have obtained reviews from multiple individuals involved with Matter. They
support publication of the draft. No directorate reviews performed but we have
agreed with our AD that he will request INT and IoT directorate review at IETF
Last Call stage.

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

It does not contain any of the above.

7. If the document contains a YANG module, has the final version of the module
   been checked with any of the [recommended validation tools][4] 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 [RFC 8342][5]?

Not applicable.

8. Describe reviews and automated checks performed to validate sections of the
   final version of the document written in a formal language, such as XML code,
   BNF rules, MIB definitions, CBOR's CDDL, etc.

It does not contain any of the above.

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
   document is needed, clearly written, complete, correctly designed, and ready
   to be handed off to the responsible Area Director?

* Needed
        Yes, there is demand for this coming from Matter and the IoT space.

* Clearly written
        In general, yes. It's a short and simple document.

* Complete

* Correctly designed
        Yes, ascertained by agreement from the WG and the mechanism making
        sense to me.

* Ready for AD

10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent

I identified the following areas in draft -03, which are now resolved from -05.

* SEC area states '"This document introduces no new security considerations [on
top of the base protocol spec]" is rarely true.'. The document's sentence 'The
addition of a record lifetime to facilitate automated garbage collection does
not itself add any significant new security concerns.' required expanding.

* TSV area states 'If a protocol contains timers, the reviewer should consider
whether there is a default value given, or a formula/algorithm for managing the
timer. Is there potential for multiple nodes, connections, or other protocol
instances have their timers synchronize and cause undesirable effects? E.g.
should the timer be randomly dithered.' Draft -03 contained potential for
message synchronization after power failure, so the requirements for timer
behaviour in -05 have been significantly tightened up.

11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])? Why is this the proper type
    of RFC? Do all Datatracker state attributes correctly reflect this intent?

Proposed Standard. This makes sense for a protocol definition with multiple
implementations. Datatracker is up to date.

12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]? To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.

The disclosed IPR is at I raised this
before I was a chair, in July 2021:
There hasn't been any pushback from the WG about this IPR.

Both authors have explicitly confirmed no additional IPR:

13. Has each author, editor, and contributor shown their willingness to be
    listed as such? If the total number of authors and editors on the front page
    is greater than five, please provide a justification.

Confirmation received from the authors, Roger Pantos, Gabriel, Jonathan, Abtin,
Kangping, Nathan, Steve, Esko, Peter, Marc and Tim. I was unable to find
current contact details for Kiren Sekar & Chris Sharp.

14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)

ID Nits
No nits found, other than referring to srp-18 rather than srp-19.

Content Guidelines
Draft -03 contained the issues described below. None of these remain in -06, so
they are included only for interest.

* The Security Considerations didn't meet the standard of "meaningful".

* IANA Considerations weren't entirely clear.

* Two abbreviations lacked expansions on first use. They are not considered
well-known in the RFC Editor's abbreviations list:
        EDNS(0)         Extension Mechanisms for DNS (EDNS(0))
        DNS-SD      DNS-based Service Discovery (DNS-SD)

* The following uses of SHOULD failed to state valid reasons for varying from
the recommendation, and the implications of doing so.
        4.1 DNS Update requestors SHOULD send an Update Lease option with any
        DNS Update that is not intended to be present indefinitely. 4.1 The
        Update Lease option SHOULD specify a time interval that is no shorter
        than 30 minutes (1800 seconds). 5.1 The Refresh message SHOULD NOT
        include any update prerequisites that would, if the state produced by
        the previous update or Refresh is still in effect, fail. 5.1 The update
        SHOULD NOT be constructed to fail in the case that the state produced
        by the previous update or Refresh has for some reason been garbage
        collected. 5.2 Requestors SHOULD Refresh resource records after 75% of
        the original lease has elapsed. 5.2 If the requestor uses UDP and does
        not receive a response from the server, the requestor SHOULD retry
        after 2 seconds. 5.2 The requestor SHOULD continue to retry, doubling
        the length of time between each retry, or retry using TCP. 5.2.1 If the
        requestor uses UDP, the requestor MUST NOT coalesce Refresh messages if
        doing so would cause truncation of the message; in this case, either
        multiple messages or TCP SHOULD be used.

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].


16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative


17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.


18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?


19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.


20. 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 aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).

The considerations section was made clearer. No other issues arise.

21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.