# Document Shepherd Write-Up for Group Documents
## 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?
The document has been discussed extensively within the BESS Working Group over
multiple years and revisions, including review from participants in both the
BESS and BFD communities. During Working Group Last Call, multiple participants
expressed support for publication and technical comments raised throughout the
document's development were addressed through subsequent revisions. I believe
the document has achieved broad working group agreement.
2. Was there controversy about particular points, or were there decisions where
the consensus was particularly rough?
The document generated technical discussion regarding the operational
implications of EVPN BFD deployment, including scaling considerations and
service-layer actions following BFD session failures. The working group
converged on keeping service-layer reactions outside the scope of the
specification and focusing the document on fault-detection procedures. These
discussions led to improvements in the document.
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.)
None indicated.
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
(where)?
The mechanisms described in the document are based on existing EVPN and BFD
technologies that are widely deployed. During working group development and last
call, multiple vendors participated in the review process and expressed support
for the document. However, although I am aware of implementation interest, there
were no known implementations declared. The document status was therefore
changed from Proposed Standard to Experimental, since it does require some code
point allocation from IANA registries to allow for interoperable and publicly
verifiable implementation.
## 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.
Yes.
The document specifies EVPN fault-management procedures built upon BFD and
therefore directly interacts with technology maintained by the BFD Working
Group. The BFD Working Group was explicitly invited to review the document
during WG Last Call and participated in the review process. In addition, the
document received Routing Directorate review during its development.
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.
The document contains no MIB modules, YANG modules, media type registrations,
URI schemes, or similar constructs requiring specialized expert review.
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. The document contains no YANG modules.
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.
The document does not contain any formal language specifications requiring such
validation.
## 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?
I believe that the document addresses an important operational
need for EVPN deployments by defining procedures for proactive network-layer
fault detection using BFD. The document is clearly written, technically sound,
and has received sufficient review to be forwarded to the responsible Area
Director.
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
reviews?
The document has received review from EVPN and BFD experts and has also
received Routing Directorate review. Comments identified during those reviews
were incorporated into subsequent revisions. I am not aware of any outstanding
issues.
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?
The requested publication type is Experimental.
The document specifies mechanisms for EVPN network-layer fault management using
BFD. Although the procedures are fully specified, and a desire to implement was
expressed, no actual implementations were publically declared and so according
to the BESS implementation policy the document could not be progressed as a
Proposed Standard. Experimental publication is therefore appropriate to
encourage implementation and operational validation of the mechanisms in a
variety of EVPN deployment scenarios. The Datatracker metadata reflects the
Experimental publication intent
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.
An IPR poll was conducted during Working Group Last Call. The authors responded
to the poll and confirmed that they were not aware of any undisclosed IPR
relating to the document. I am not aware of any undisclosed IPR. No IPR
disclosures have been filed against the document.
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.
Yes.
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
authors.ietf.org][15]. (Also note that the current idnits tool generates
some incorrect warnings; a rewrite is underway.)
I am not aware of any remaining issues that would prevent publication. There
are a couple of remaining nits that are editorial in nature and can be
addressed during IESG review or RFC Editor processing.
15. Should any informative references be normative or vice-versa? See the [IESG
Statement on Normative and Informative References][16].
The normative and informative references are appropriately classified.
16. List any normative references that are not freely available to anyone. Did
the community have sufficient access to review any such normative
references?
I am not aware of any normative references that are not publicly available.
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.
I am not aware of any normative downward references requiring special handling.
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?
All normative references are to published RFCs.
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.
No.
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]).
I reviewed this section and noted one comment. The draft originally requested an
allocation of a PW associated channel type for the PW ACH registry, which has
been replaced by the "MPLS Generalized Associated Channel (G-ACh) Types
(including Pseudowire Associated Channel Types) ". Teh draft was corrected
accordingly.
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.
No new registries required.