Template date: 24 February 2012.
(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?
(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:
This document defines a way for a Border Gateway Protocol Link-State
(BGP-LS) speaker to advertise multiple types of supported Maximum SID
Depths (MSDs) at node and/or link granularity.
Such advertisements allow entities (e.g., centralized controllers) to
determine whether a particular Segment Identifier (SID) stack can be
supported in a given network.
Working Group Summary
Was there anything in WG process that is worth noting?
2 IPR filed on this work
2 implementation are only cisco
WG LC is at:
For example, was there controversy about particular points or
were there decisions where the consensus was particularly
rough? WG consensus was postive with indications of
that this feature was needed in BGP-LS neworks.
Are there existing implementations of the protocol?
2 Cisco implementations have indicated support for the protocol.
see report at:
Have a significant number of vendors indicated their plan to
implement the specification?
Additional vendors with segment routing implementations
have indicated they which to add the MSD feature.
No additional vendors indicated a plan to implement the IDR MSD feature.
However, there is support for this feature in SR in the LSR WG.
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?
RTG-DIR: Mach Chen
If there was a MIB Doctor, Media Type or other expert review,
what was its course (briefly)?
OPS-DIR early review requested: pending
Who is the Document Shepherd? Susan Hares
Who is the Responsible AD? Alvaro Retana
RTG-DIR early review: Mach Chen
(3) Briefly describe the review of this document that was performed by
the Document Shepherd.
1. NITS run on each version.
2. Review of entire document and dependents
(-04.txt, -05.txt, -06.txt, -07.txt, -08.txt)
Current text in shepherd:
The document lacks error handling section that indicates
what happens if the TLVS are incorrectly parsed.
Needs draft-ietf-idr-rfc7752bis-00 reference and clarified
management based on yang models.
3. RTG-DIR QA: Mach Chen
Ready. Minor nits he mentioned addressed in -08.txt
If this version of the document is not ready
for publication, please explain why the document is being forwarded to
(4) Does the document Shepherd have any concerns about the depth or
breadth of the reviews that have been performed?
No. The WG has been asked about
(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
This is a normal SR draft so the following suggestions are made for the reviewers:
RTG-DIR Review should look LSR documents linked.
OPS-DIR review should look at operational support of the SR function.
To this shepherd, MSD seems to improve the manageability of the
SR functions in a network.
(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
RFC7752 is being revised by IDR to clarify sections in the draft
based on implementation experience. Rushing RFC7752bis to
completion is unwise since it takes careful review of the implementation
reports to address the places where RFC7752 is unclear.
RFC7752 and segment routing (SR) are in use with
centralized controllers. This specification addresses a known
need in deployed SR. Therefore it is unwise to hold this
specification back or hurry RFC7752bis.
There may not be substantial discussion on this point
because the people developing BGP and the people operating
BGP realize we have a balancing act as we deploy segment routing features.
We must balance sending forward features that aid deployments
and clarify the RFC752bis specification so that new implementations
may be interoperable with existing implementations.
(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.
Jeff Tantsura (Apstra, Inc.)
Uma Chunduri (Futurewei)
Ketan Talaulikar (Cisco Systems)
Contributor: Siva Sivabalan
(8) Has an IPR disclosure been filed that references this document?
If so, summarize any WG discussion and conclusion regarding the IPR
WG Call for the WG approval of IPR on drafts:
Please note that the IPR on this feature may preclude open source
implementations from creating it.
(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?
11 people indicated a strong support.
There are 2 Cisco interoperable implementations.
WG Approval of 2 Cisco implementations to send to IESG.
WG response is at:
(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 public appeals or discontent on mail list.
(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
No NITS founds.
(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.
(13) Have all references within this document been identified as
either normative or informative?
All references are normative.
(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?
All normative references are RFCS.
(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 normative references are downward 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.
(17) Describe the Document Shepherd's review of the IANA considerations
section, especially with regard to its consistency with the body of the
This document requests assigning code-points from the registry "BGP-
LS Node Descriptor, Link Descriptor, Prefix Descriptor, and Attribute
TLVs" based on table below. Early allocation for these code-points
have been done by IANA.
| Code Point | Description | IS-IS TLV/Sub-TLV |
| 266 | Node MSD | 242/23 |
| 267 | Link MSD | (22,23,25,141,222,223)/15 |
(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.
(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.
No XML code, BNF rules, MIB definitions.
References to all Yang models have been checked.