As required by RFC 4858, this is the current template for the Document
Changes are expected over time. This version is dated 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?
Proposed Standard is requested. This is in the Document header.
This is appropriate because this Document specifies the generic functions of the architecture,
when applied to MPLS, even if no change is made to the MPLS data plane.
(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:
Segment Routing (SR) leverages the source routing paradigm. A node
steers a packet through a controlled set of instructions, called
segments, by prepending the packet with an SR header. In the MPLS
dataplane, the SR header is instantiated through a label stack. A
segment can represent any instruction, topological or service-based.
Additional segments can be defined in the future. SR allows to
enforce a flow through any topological path and/or service chain
while maintaining per-flow state only at the ingress node to the SR
Segment Routing can be directly applied to the MPLS architecture with
no change in the forwarding plane. This drafts describes how Segment
Routing operates on top of the MPLS data plane.
Working Group Summary
There is consensus amongst the Working Group to progress this Document towards becoming a Proposed Standard RFC
The Document is quite well written and has undergone editing work to become more focused on its key aspect.
Several implementations of Segment Routing exist.
Shraddha Hegde is the Document Shepherd
Martin Vigoureux is the Responsible Area Director
(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 Document Shepherd has done a full review of the Document following up the reviews which were made as part of the WG LC.
There was active WG involvement in the review of the document which resulted in an appendix with clear examples.
(4) Does the document Shepherd have any concerns about the depth or
breadth of the reviews that have been performed?
(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
(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
(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.
All the authors have confirmed that.
(8) Has an IPR disclosure been filed that references this document?
If so, summarize any WG discussion and conclusion regarding the IPR
3 IPR disclosures exist against this Document. No specific opinion was expressed with regard to these disclosures.
(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 Working Group consensus is solid.
(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.)
(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
IDnits is clean (except for the absence of IPv6 addresses in the illustration examples)
(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 criteria applies to this Document.
(13) Have all references within this document been identified as
either normative or informative?
(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 standards.
(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.
(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.
This Document will not change the status of any pre-existing RFC.
(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).
This Document makes no request to IANA.
(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.