The MPLS Working Group requests that
SR-MPLS over IP
is published as an RFC on the standards track
(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?
- we request that the document is published as a Proposed Standard.
- the title page header says "Standards Track"
- PS is the proper type of RFC since the document specifies new
protocol procedures for SR-MPLS capable LSRs.
(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:
- SR-MPLS is a source routing paradigm for the MPLS data plane.
SR-MPLS allows the sender of the packet to (partly or completely)
specify the route the packet takes through an MPLS network, this is
done by encapsulating the packet in a label stack.
- SR-MPLS may be used realize a source routing mechanism across MPLS,
IPv4, and IPv6 data planes. While SR-MPLS works seamlessly over
MPLS and SRv6 capable networks, it does not work over IPv4 networks
without this mechanism. The MPLS label stack is used as a
set of source routing instructions, being backward compatible with
- This document describes how SR-MPLS capable LSRs, non-SR MPLS
capable LSRs and IP-only routers can seamlessly co-exist and
interoperate through the use of SR-MPLS label stacks and IP
encapsulation, such as MPLS-in-UDP as defined in RFC 7510.
Working Group Summary
Was there anything in WG process that is worth noting? For
example, was there controversy about particular points or
were there decisions where the consensus was particularly
- The working group process has been very smooth and straight
forward. We have very good support for the document.
- Early there were two competing individual documents, and the
discussion was quite heated. The WG chairs for both the SPRING and
MPLS working groups early suggested to merge the documents. That
this merge actually could take place is very much thanks to the strong
leadership of Zhenbin (Robin) Li who worked with the the two author
teams to make this happen.
- Most of the discussion on which working group should progress the
draft took place before making the draft a working group document.
That discussion was whether the document should be progressed
in SPRING or MPLS, since this builds on RFC 7510 (an MPLS RFC) and
describes how the MPLS label stack is used as a set of source
routing instructions, the discussion converged on progressing the
document in the MPLS WG.
Are there existing implementations of the protocol? Have a
significant number of vendors indicated their plan to
implement the specification? 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? If
there was a MIB Doctor, Media Type or other expert review,
what was its course (briefly)? In the case of a Media Type
review, on what date was the request posted?
- we do not currently know for certain if there are implementations
of this specification. An implementation poll has been sent to the
MPLS working group, the shepherd write-up will be updated as soon
as we get further information.
- there were no special reviews outside the normal working group
process (MPLS-RT review, adoption poll, mailing list discussion
Who is the Document Shepherd? Who is the Responsible Area
- Loa Anderson is the Document Shepherd
- Deborah Brungard 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 reviewed the document basically at the
steps in the working group process, when the documents that were
merged were posted, when the documents were merged, before the WGAP
(4) Does the document Shepherd have any concerns about the depth or
breadth of the reviews that have been performed?
- No such concerns
(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
- No such reviews needed.
(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
- No such concerns
(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 co-authors have stated on the MPLS mailing list that they
are unaware of any non-disclosed IPRs relating to this document.
- All the contributors has stated on the MPLS mailing list that they
are unaware of any non-disclosed IPRs relating to this document.
- There are 6 co-authors and 13 contributors, the process to get
responses to the IPR poll were lengthy. When we sent the document
to WGLC one of the contributors had not responded to the IPR poll.
The working group was notified about this, but it generated no
discussion, and during the WGLC we got the final response in.
- the high number of authors/contributors is becasue this is a merge
of two documents, and both document contributed both authors and
contributors, the number of authors has been decrease to an
acceptable number (6), by moving former "authors" to
"contributors". This has been done even though we know that among
the listed contributors there are people that have independently
contributed text. The process of reducing the number of authors
has required quite a bit discussion, and the WG chairs and the
WG very appreciate the spirit of cooperation that made this
(8) Has an IPR disclosure been filed that references this document?
If so, summarize any WG discussion and conclusion regarding the IPR
- There are two IPR disclosures against documents that were
predecessors to the working group document, they are both pointing
to the same US patent.
The working group has been notified of the IPR disclosures, but no
discussion toom place. The customary interpretation of this is is
that the conditions listed in the IPR disclosures are acceptable to
the working group.
(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 support for this document is very strong.
(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 such threats
(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
- The document passes ID nits clean
(12) Describe how the document meets any required formal review
criteria, such as the MIB Doctor, media type, and URI type reviews.
- No such formal reviews necessary
(13) Have all references within this document been identified as
either normative or informative?
- All references are correctly split into Normative and 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 the normative references (with one exception) are to published
standard track RFCs.
- The exception is ietf-spring-segment-routing-mpls, which has been
submitted to the IESG for publication.
(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 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.
- the publication of this document will not change the status of any
(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).
- There are no request for IANA actions in this document
(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.
- No new regisgtries are specified in the document
(19) Describe reviews and automated checks performed by the Document
Shepherd to validate sections of the document written in a forchecks or mal
language, such as XML code, BNF rules, MIB definitions, etc.
- No such automated checks or reviews are necessary.