MPLS Transport Encapsulation for the Service Function Chaining (SFC) Network Service Header (NSH)
draft-ietf-mpls-sfc-encapsulation-04

[Ballot comment]
Without having looked before I was thinking this was Standard Track, I'm surprised it is not.

You say:
  1.  Push zero or more labels that are interpreted by the destination
      MPLS node on to the packet,
and then say:
  The receiving MPLS node then pops the SFF Label (and any labels
  beneath it)
So it looks like that any label which might have been pushed before the SFF label is/are simply ignored at the other end.
I'm not asking for the behaviour to be specified and I understand that strictly speaking the text is not forbidding something to happen based on these labels but still it might be useful to explicitly say that these labels may be processed.

[Ballot discuss]
Thanks for this clear and concise document!  I just have one concern,
which will hopefully be easy to resolve (since there is a good chance
that all the text necessary to do so is already written).

As far as I can tell, the comment made by the secdir reviewer of
draft-ietf-mpls-sfc-04 about circular references between that document
and RFCs 7665 and 8300 regarding security properties, is also somewhat
applicable to this document.  I do recognize the validity of first
paragraph of the security considerations here (the NSH is an opaque
payload for MPLS), but that in and of itself does not present a security
analysis of the NSH in the MPLS environment.  The last paragraph of the
security considerations of this document attempts to provide some
analysis, but it seems to be incomplete and perhaps overly optimistic,
particularly with respect to the use of MPLS with Inter-Carrier
Interconnect and the processing of MPLS traffic from external
interfaces.  Is there any reason not to fully harmonize (i.e.,
synchronize) the security considerations of draft-ietf-mpls-sfc and
draft-ietf-mpls-sfc-encapsulation?  (I guess the first paragraph of this
document's security considerations doesn't apply to the other document,
that allocates extended-special-purpose label values, but that's the
only thing I saw.)

[Ballot comment]
Section 1

  This encapsulation is equivalent from an SFC perspective to other
  transport encapsulations of packets using the NSH.  This can be
  illustrated by adding an additional line to the example of a next-hop
  SPI/SI-to-network overlay network locator mapping in Table 1 of
  [RFC8300]:

We probably should expand SPI and SI, since we haven't yet hit a
terminiology section or a note that (implies that) readers should be
familiar with the standard SFC terminology.
Also, Table 1 of RFC 8300 is labeled "SFF NSH Mapping Example"; it's not
really clear that specifically that table is the best way to illustrate
how the MPLS encapsulation would work.

(side note) We use the strings "VPN" and "virtual private" here, which
in some contexts will cause an (uninformed) reader to assume that data
privacy (confidentiality) is involved; our uses do not seem to be for
cases that would involve such a confidentiality property.  As a general
matter, not necessarily involving changes to this document, it may be
good to try to reserve these terms for cases where the confidentiality
is in fact provided, to help disambiguate the cases for the reader.

Section 2.1

nit: s/The TTL For/The TTL for/ (twice)

Section 3

  For SFC, ECMP may or may not be desirable.  To prevent ECMP when it
  is not desired, the NSH Base Header was carefully constructed so that
  the NSH could not look like IPv4 or IPv6 based on its first nibble.
  See Section 2.2 of [RFC8300] for further details.

nit: this paragraph might flow better into the next one if we add a note
that "Accordingly, the default behavior for MPLS-encapsulated SFC will
not use ECMP."

Section 6

  However, it can be argued that carrying the NSH over MPLS is more

re: "it can be argued" -- is this document attempting to make that argument?

  secure than using other encapsulations, as it is extremely difficult,
  due to the MPLS architecture, for an attempted attacker to inject

It's not entirely clear to me how much of this is the MPLS architecture
vs. implementation/deployment; I suppose to some extent it is true of
both.

  unexpected MPLS packets into a network, as MPLS networks do not by
  design accept MPLS packets from external interfaces, and an attacker

What about Inter-Carrier Interconnect?

  would need knowledge of the specific labels allocated by control and/
  or management plane protocols.  Thus, an attacker attempting to spoof
  MPLS-encapsulated NSH packets would require insider knowledge of the

An attacker in a position to inject traffic seems likely to also be able
to observe legitimate traffic and correspondingly their valid label
values (if not necessarily the mapping from label to behavior).

  network's control and management planes and a way to inject packets
  into internal interfaces.  This is compared to, for example, NSH over
  UDP over IP, which could be injected into any external interface in a
  network that was not properly configured to filter out such packets
  at the ingress.

The NSH security considerations already (essentially) require this
filtering at ingress behavior; the practical question relevant here
seems to just be a matter of scale -- how hard it is to misconfigure
this filtering or how likely it is that the relevant filtering is
present as a consequence of factors external to SFC.

[Ballot comment]
Not sure about the document's intended status as informational. The doc does not specify a new protocol but it does give normative instructions on the used of protocols. However, I leave this decision to the responsible AD and WG.

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

The IANA Functions Operator has reviewed draft-ietf-mpls-sfc-encapsulation-02, which is currently in Last Call, and has the following comments:

We understand that this document doesn't require any registry actions.

While it's often helpful for a document's IANA Considerations section to remain in place upon publication even if there are no actions, if the authors strongly prefer to remove it, we do not object.

If this assessment is not accurate, please respond as soon as possible.

Thank you,

Amanda Baber
Lead IANA Services Specialist

The following Last Call announcement was sent out (ends 2019-02-26):

From: The IESG
To: IETF-Announce
CC: mpls@ietf.org, db3546@att.com, draft-ietf-mpls-sfc-encapsulation@ietf.org, mpls-chairs@ietf.org, Loa Andersson , loa@pi.nu
Reply-To: ietf@ietf.org
Sender:
Subject: Last Call:  (MPLS Encapsulation For The SFC NSH) to Informational RFC


The IESG has received a request from the Multiprotocol Label Switching WG
(mpls) to consider the following document: - 'MPLS Encapsulation For The SFC
NSH'
  as Informational RFC

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 2019-02-26. 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 describes how to use a Service Function Forwarder (SFF)
  Label (similar to a pseudowire label or VPN label) to indicate the
  presence of a Service Function Chaining (SFC) Network Service Header
  (NSH) between an MPLS label stack and the packet payload.  This
  allows SFC packets using the NSH to be forwarded between SFFs over an
  MPLS network, and to select one of multiple SFFs in the destination
  MPLS node.




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-mpls-sfc-encapsulation/

IESG discussion can be tracked via
https://datatracker.ietf.org/doc/draft-ietf-mpls-sfc-encapsulation/ballot/


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

  The MPLS working group requests that

                    MPLS Encapsulation For The SFC NSH
                  draft-ietf-mpls-sfc-encapsulation-02

  is published as an Informational RFC

(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 are requesting the document is published as an
  Informational RFC
- It is the proper type of the RFC since no new protocol is
  specified
- The title page says Informational

(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

- This document describes how a SFF Label can be used to indicate
    the presence of a SFC Network Service Header (NSH)) between
    an MPLS label stack and the packet payload. The SFF Label is in
    many ways similar to a pseudowire label or VPN label. This allows
    SFC packets to be forwarded between SFFs across an MPLS network.
    The SFF Label allows for one or more SFFs in the destination LSR.

Working Group Summary

- The working group process has been swift and there is strong
  support for the document.

Document Quality

  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?

- This informational document follows well-established MPLS
  procedures and does not require any actions by IANA or any new
  protocol extensions.

- no expert reviews necessary.

Personnel

- Loa Andersson 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 IESG.

- The Document Shepherd has reviewed the document
  -- when it was first posted
  -- when we were preparing wgap
  -- when the wglc was prepared

(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
took place.

- no such reviews necessary.

(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.

- nu 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 authors have confirmed that they are unaware of any existing
  IPRs that would be necessary for this document.

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

- there are no IPR disclosures against this document

(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
thorough.

- the document passes the nits tool 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 reviews necessary

(13) Have all references within this document been identified as
either normative or informative?

- the 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 are to existing Standard Track 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.

(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 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 does not request any IANA actions

(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 IANA registries, that requires Expert Reviews or otherwise
  are defined in this document

(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 such automated checks necessary

  The MPLS working group requests that

                    MPLS Encapsulation For The SFC NSH
                  draft-ietf-mpls-sfc-encapsulation-02

  is published as an Informational RFC

(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 are requesting the document is published as an
  Informational RFC
- It is the proper type of the RFC since no new protocol is
  specified
- The title page says Informational

(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

- This document describes how a SFF Label can be used to indicate
    the presence of a SFC Network Service Header (NSH)) between
    an MPLS label stack and the packet payload. The SFF Label is in
    many ways similar to a pseudowire label or VPN label. This allows
    SFC packets to be forwarded between SFFs across an MPLS network.
    The SFF Label allows for one or more SFFs in the destination LSR.

Working Group Summary

- The working group process has been swift and there is strong
  support for the document.

Document Quality

  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?

- This informational document follows well-established MPLS
  procedures and does not require any actions by IANA or any new
  protocol extensions.

- no expert reviews necessary.

Personnel

- Loa Andersson 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 IESG.

- The Document Shepherd has reviewed the document
  -- when it was first posted
  -- when we were preparing wgap
  -- when the wglc was prepared

(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
took place.

- no such reviews necessary.

(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.

- nu 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 authors have confirmed that they are unaware of any existing
  IPRs that would be necessary for this document.

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

- there are no IPR disclosures against this document

(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
thorough.

- the document passes the nits tool 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 reviews necessary

(13) Have all references within this document been identified as
either normative or informative?

- the 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 are to existing Standard Track 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.

(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 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 does not request any IANA actions

(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 IANA registries, that requires Expert Reviews or otherwise
  are defined in this document

(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 such automated checks necessary

  The MPLS working group requests that

                    MPLS Encapsulation For The SFC NSH
                  draft-ietf-mpls-sfc-encapsulation-02

  is published as an Informational RFC

(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 are requesting the document is published as an
  Informational RFC
- It is the proper type of the RFC since no new protocol is
  specified
- The title page says Informational

(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

- This document describes how a SFF Label can be used to indicate
  the presence of a SFC NSH) between an MPLS label stack and the
  packet payload. The SFF Label is in many ways similar to a
  pseudowire label or VPN label. This allows SFC packets to be
  forwarded between SFFs across an MPLS network. The SFF Label
  allows for one or more SFFs in the destination LSR..

Working Group Summary

- The working group process has been swift and there is strong
  support for the document.

Document Quality

  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?

- This informational document follows well-established MPLS
  procedures and does not require any actions by IANA or any new
  protocol extensions.

- no expert reviews necessary.

Personnel

- Loa Andersson 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 IESG.

- The Document Shepherd has reviewed the document
  -- when it was first posted
  -- when we were preparing wgap
  -- when the wglc sere prepared

(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
took place.

- no such reviews necessary.

(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.

- nu 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 authors have confirmed that they are unaware of any existing
  IPRs that would be necessary for this document.

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

- there are no IPR disclosures against this document

(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
thorough.

- the document passes the nits tool 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 reviews necessary

(13) Have all references within this document been identified as
either normative or informative?

- the 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 are to existing Standard Track 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.

(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 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 does not request any IANA actions

(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 IANA registries, that requires Expert Reviews or otherwise
  are defined in this document

(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 such automated checks necessary

  The MPLS working group requests that

                    MPLS Encapsulation For The SFC NSH
                  draft-ietf-mpls-sfc-encapsulation-02

  is published as an Informational RFC

(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 are requesting the the document is published as an
  Informational RFC
- It is the proper type of the RFC since no new protocol is
  specified
- The title page says Informational

(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

- This document describes how a SFF Label can be used to indicate
  the presence of a SFC NSH) between an MPLS label stack and the
  packet payload. The SFF Label is in many ways similar to to a
  pseudowire label or VPN label. This allows SFC packets to be
  forwarded between SFFs across an MPLS network. The SFF Label
  allows for one or more SFFs in the destination LSR..

Working Group Summary

- The working group process has been swift and there is strong
  support for the ducment.

Document Quality

  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?

- This informational document follows well-established MPLS
  procedures and does not require any actions by IANA or any new
  protocol extensions.

- no expert reviews necessary.

Personnel

- Loa Andersson 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 IESG.

- The Document Shepherd has reviewed the document
  -- when it was first posted
  -- when we were preparing wgap
  -- when the wglc sere prepared

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

- no such concderns

(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 such reviews necessary.

(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.

- nu such concderns

(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 authors has confirmed that they are unaware of any existing
  IPRs that would be necessary for this document.

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

- there are no IPR disclosures against this document

(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
thorough.

- the document passes the nits tool 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 reviews necessary

(13) Have all references within this document been identified as
either normative or informative?

- the refrences 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 refrences are to existing Standard Track 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.

(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 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 does not request any IANA actions

(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 IANA registries, that requires Expert Reviews or otherwise
  are defined in this document

(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 such automated checks necessary