Advertising Seamless Bidirectional Forwarding Detection (S-BFD) Discriminators in IS-IS
draft-ietf-isis-sbfd-discriminator-02

[Ballot comment]
The BFD WG has come to consensus on the path forward resulting in the requirement to know about discriminators assigned, and not explicit mapping to individual functions.  The base S-BFD document (draft-ietf-bfd-seamless-base) has been updated appropriately.

I'm clearing my DISCUSS.

[Ballot discuss]
It has been pointed out during the processing of this document (and other similar ones, draft-ietf-ospf-sbfd-discriminator, for example) that the functionality provided is only the advertisement of S-BFD discriminators, but not a mechanism to map these discriminators to specific applications or use-cases in the nodes.  That mapping has been declared out of scope.

However, the Base S-BFD draft (draft-ietf-bfd-seamless-base) assumes that the advertisers of the multiple discriminators will in fact provide the ability for the mapping.  Specifically, the base S-BFD document reads in Section 3. (Seamless BFD Overview):

  An S-BFD module on each network node allocates one or more S-BFD
  discriminators for local entities, and creates a reflector BFD
  session.  Allocated S-BFD discriminators may be advertised by
  applications (e.g., OSPF/IS-IS).  Required result is that
  applications, on other network nodes, possess the knowledge of the
  mapping from remote entities to S-BFD discriminators.

This text reads to me that S-BFD is expecting the mapping to be somehow provided by the "applications (e.g., OSPF/IS-IS)".  There's no other explicit discussion about the mapping in that document.

I'm putting a DISCUSS on this document to hold its processing while the requirements from the S-BFD point of view are clarified.  The answer to that question should be a discussion in the BFD WG (cc'd in this message), in coordination with the providers of the advertisements (so far the isis, ospf and l2tpext WGs have active drafts in this area).

One possible outcome of this required discussion is clearly that the mapping is in fact outside the scope of advertising protocols (such as IS-IS).  Other possible outcomes may require this document to be modified.

[Ballot comment]
As mentioned by Menachem in his OPS DIR review:
NITS
====

The NITS Tool founds the following warnings:

== The document seems to contain a disclaimer for pre-RFC5378 work, but was
    first submitted on or after 10 November 2008.  The disclaimer is usually
    necessary only for documents that revise or obsolete older RFCs, and that
    take significant amounts of text from those RFCs.  If you can contact all
    authors of the source material and they are willing to grant the BCP78
    rights to the IETF Trust, you can and should remove the disclaimer.
    Otherwise, the disclaimer is needed and you can ignore this comment.
    (See the Legal Provisions document at
    http://trustee.ietf.org/license-info for more information.)


== Outdated reference: A later version (-05) exists of
    draft-ietf-bfd-seamless-base-04


-----------------------------------------

In addition the following sentence may need clarification:

"When multiple S-BFD discriminators are advertised how a given discriminator is mapped to a specific use case is out of scope for this document."

It was not clear to me whether this is defined or will be defined in a different document or whether this is left open for each implementation.

[Ballot comment]
Please expand S-BFD, both in the abstract and the body. (I see an expansion of BFD in the body, but not one for S-BFD)

(Via drafts-lastcall-comment@iana.org): IESG/Authors/WG Chairs:

IANA has completed its review of draft-ietf-isis-sbfd-discriminator-02.txt. If any part of this review is inaccurate, please let us know.

IANA understands that, upon approval of this document, there is a single action which IANA must complete.

In the Sub-TLVs for TLV 242 subregistry of the IS-IS TLV Codepoints registry located at:

http://www.iana.org/assignments/isis-tlv-codepoints/

a new Sub-TLV will be registered as follows:

Value: [ TBD-at-Registration ]
Description: S-BFD Discriminators
Reference: [ RFC-to-be ]

IANA notes that the authors have suggested a value of 20 be used for this registration.

As this document requests registrations in an Expert Review or Specification Required (see RFC 5226) registry, we will initiate the required Expert Review via a separate request. Expert review will need to be completed before your document can be approved for publication as an RFC.

IANA understands that this is the only action required to be completed upon approval of this document.

Note:  The actions requested in this document will not be completed until the document has been approved for publication as an RFC. This message is only to confirm what actions will be performed. 

Please note that IANA cannot reserve specific values. However, early allocation is available for some types of registrations. For more information, please see RFC 7120.

The following Last Call announcement was sent out:

From: The IESG
To: "IETF-Announce"
CC: draft-ietf-isis-sbfd-discriminator@ietf.org, isis-wg@ietf.org, chopps@chopps.org, isis-chairs@ietf.org, akatlas@gmail.com
Reply-To: ietf@ietf.org
Sender:
Subject: Last Call:  (Advertising S-BFD Discriminators in IS-IS) to Proposed Standard


The IESG has received a request from the IS-IS for IP Internets WG (isis)
to consider the following document:
- 'Advertising S-BFD Discriminators in IS-IS'
  as Proposed Standard

The IESG plans to make a decision in the next few weeks, and solicits
final comments on this action. Please send substantive comments to the
ietf@ietf.org mailing lists by 2015-11-16. Exceptionally, comments may be
sent to iesg@ietf.org instead. In either case, please retain the
beginning of the Subject line to allow automated sorting.

Abstract


  This document defines a means of advertising one or more S-BFD
  Discriminators using the IS-IS Router Capability TLV.





The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-isis-sbfd-discriminator/

IESG discussion can be tracked via
https://datatracker.ietf.org/doc/draft-ietf-isis-sbfd-discriminator/ballot/


No IPR declarations have been submitted directly on this I-D.

    (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.

    (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:

Utilize IS-IS router capability TLV to advertise per-node S-BFD discriminator.

    Working Group Summary:

Good consensus in the working group.

    Document Quality:

Implementations are being planned, dependent on the general S-BFD feature.

    Personnel:

Shepherd: Christian Hopps
AD: Alia Atlas

    (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.

Reviewed by the shepherd.

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

None

    (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.

No broader review required.

    (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.

None

    (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?

No new IPR related to IS-IS document.

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

No see above.

    (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?

Solid consensus.

    (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.

    (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.

None.

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

No formal review required.

    (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.

    (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.

    (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.

    (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).

Confirmed registry association and identification.

    (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.

None.

    (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.

None.