Path Computation Element Communication Protocol (PCEP) Extensions for Segment Routing (SR) Policy Candidate Paths
draft-ietf-pce-segment-routing-policy-cp-18

IESG/Authors/WG Chairs:

IANA has completed its review of draft-ietf-pce-segment-routing-policy-cp-18. If any part of this review is inaccurate, please let us know.

IANA understands that, upon approval of this document, there are eight actions which we must complete.

First, in the ASSOCIATION Type Field registry in the Path Computation Element Protocol (PCEP) Numbers registry group located at:

https://www.iana.org/assignments/pcep/

the existing early allocation for Type: 6; Description SR Policy Association will be made permanent and its reference changed to [ RFC-to-be ].

Second, in the PCEP TLV Type Indicators also in the Path Computation Element Protocol (PCEP) Numbers registry group located at:

https://www.iana.org/assignments/pcep/

the eight early allocations for the following type indicators will be made permanent and their references changed to [ RFC-to-be ]:

| 56 | SRPOLICY-POL-NAME
| 57 | SRPOLICY-CPATH-ID
| 58 | SRPOLICY-CPATH-NAME
| 59 | SRPOLICY-CPATH-PREFERENCE
| 68 | COMPUTATION-PRIORITY
| 69 | EXPLICIT-NULL-LABEL-POLICY
| 70 | INVALIDATION
| 71 | SRPOLICY-CAPABILITY

Third, in the PCEP-ERROR Object Error Types and Values TE-PATH-BINDING TLV Flag field also in the Path Computation Element Protocol (PCEP) Numbers registry group located at:

https://www.iana.org/assignments/pcep/

the existing, temporary registrations for one new Error-Value within the "Mandatory Object Missing" Error-Type and two new Error-Values within the "Association Error" Error-Type will be made permanent and their references changed to [ RFC-to-be ]:

+------------+------------------+-----------------------+----------------+
| Error-Type | Meaning | Error-value | Reference |
+------------+------------------+-----------------------+----------------+
| 6 | Mandatory Object | | [RFC5440] |
| | Missing | | |
+------------+------------------+-----------------------+----------------+
| | | 21: Missing SR | [ RFC-to-be ] |
| | | Policy Mandatory TLV | |
+------------+------------------+-----------------------+----------------+
| 26 | Association | | [RFC8697] |
| | Error | | |
+------------+------------------+-----------------------+----------------+
| | | 20: SR Policy | [ RFC-to-be ] |
| | | Identifers Mismatch | |
+------------+------------------+-----------------------+----------------+
| | | 21: SR Policy | [ RFC-to-be ] |
| | | Candidate Path | |
| | | Identifier Mismatch | |
+------------+------------------+-----------------------+----------------+

Fourth, in the TE-PATH-BINDING TLV Flag field also in the Path Computation Element Protocol (PCEP) Numbers registry group located at:

https://www.iana.org/assignments/pcep/

the early allocation for Bit Position: 1; Description: S (Specified-BSID-only) will be made permanent and its reference changed to [ RFC-to-be ].

Fifth, a new registry is to be created called the SR Policy Protocol Origin registry. The new registry will be located in the Segment Routing registry group located at:

https://www.iana.org/assignments/segment-routing/

The new registry will be managed via Specification Required as defined in RFC8126. There are initial registrations in the new registry as follows:

+--------------+----------------------------------------+----------------+
| Value | Description | Reference |
+--------------+----------------------------------------+----------------+
| 0 | Reserved (not to be used) | [ RFC-to-be ] |
+--------------+----------------------------------------+----------------+
| 1-9 | Unassigned | [ RFC-to-be ] |
+--------------+----------------------------------------+----------------+
| 10 | PCEP (in PCEP) | [ RFC-to-be ] |
+--------------+----------------------------------------+----------------+
| 11-19 | Unassigned | [ RFC-to-be ] |
+--------------+----------------------------------------+----------------+
| 20 | BGP SR Policy (in PCEP) | [ RFC-to-be ] |
+--------------+----------------------------------------+----------------+
| 21-29 | Unassigned | [ RFC-to-be ] |
+--------------+----------------------------------------+----------------+
| 30 | Configuration (CLI, YANG model via | [ RFC-to-be ] |
| | NETCONF, etc.) (in PCEP) | |
+--------------+----------------------------------------+----------------+
| 31-250 | Unassigned | [ RFC-to-be ] |
+--------------+----------------------------------------+----------------+
| 251 - 255 | Private Use (not to be assigned by | [ RFC-to-be ] |
| | |ANA) | |
+--------------+----------------------------------------+----------------+

Sixth, another new registry is to be created called the SR Policy ENLP Values registry. The new registry will be located in the Segment Routing registry group located at:

https://www.iana.org/assignments/segment-routing/

The new registry will be managed via Standards Action as defined in RFC8126. There are initial registrations in the new registry as follows:

+----------+--------------------------------------------+----------------+
| Value | Description | Reference |
+----------+--------------------------------------------+----------------+
| 0 | Reserved (not to be used). | [ RFC-to-be ] |
+----------+--------------------------------------------+----------------+
| 1 | Push an IPv4 Explicit NULL label on an | [ RFC-to-be ] |
| | unlabeled IPv4 packet, but do not push an | |
| | IPv6 Explicit NULL label on an unlabeled | |
| | IPv6 packet. | |
+----------+--------------------------------------------+----------------+
| 2 | Push an IPv6 Explicit NULL label on an | [ RFC-to-be ] |
| | unlabeled IPv6 packet, but do not push an | |
| | IPv4 Explicit NULL label on an unlabeled | |
| | IPv4 packet. | |
+----------+--------------------------------------------+----------------+
| 3 | Push an IPv4 Explicit NULL label on an | [ RFC-to-be ] |
| | unlabeled IPv4 packet, and push an IPv6 | |
| | Explicit NULL label on an unlabeled IPv6 | |
| | packet. | |
+----------+--------------------------------------------+----------------+
| 4 | Do not push an Explicit NULL label. | [ RFC-to-be ] |
+----------+--------------------------------------------+----------------+
| 5 - 255 | Reserved. | [ RFC-to-be ] |
+----------+--------------------------------------------+----------------+

Seventh, another new registry is to be created called the SR Policy Invalidation Operational Flags registry. The new registry will be located in the Segment Routing registry group located at:

https://www.iana.org/assignments/segment-routing/

The new registry will be managed via Standards Action as defined in RFC8126. There are initial registrations in the new registry as follows:

+-------+-----------------------------------------------+----------------+
| Bit | Description | Reference |
+-------+-----------------------------------------------+----------------+
| 0 - 6 | Unassigned | [ RFC-to-be ] |
+-------+-----------------------------------------------+----------------+
| 7 | D: dropping - the LSP is currently attracting | [ RFC-to-be ] |
| | traffic and actively dropping it. | |
+-------+-----------------------------------------------+----------------+

Eighth, another new registry is to be created called the SR Policy Invalidation Configuration Flags registry. The new registry will be located in the Segment Routing registry group located at:

https://www.iana.org/assignments/segment-routing/

The new registry will be managed via Standards Action as defined in RFC8126. There are initial registrations in the new registry as follows:

+-------+-----------------------------------------------+----------------+
| Bit | Description | Reference |
+-------+-----------------------------------------------+----------------+
| 0 - 6 | Unassigned. | [ RFC-to-be ] |
+-------+-----------------------------------------------+----------------+
| 7 | D: drop enabled - the Drop-upon-invalid is | [ RFC-to-be ] |
| | enabled on the LSP. | |
+-------+-----------------------------------------------+----------------+

We understand that these are the only actions 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 meant only to confirm the list of actions that will be performed.

For definitions of IANA review states, please see:

https://datatracker.ietf.org/help/state/draft/iana-review

Thank you,

David Dong
IANA Services Sr. Specialist

The following Last Call announcement was sent out (ends 2024-11-11):

From: The IESG
To: IETF-Announce
CC: dd@dhruvdhody.com, draft-ietf-pce-segment-routing-policy-cp@ietf.org, pce-chairs@ietf.org, pce@ietf.org, rdd@cert.org
Reply-To: last-call@ietf.org
Sender:
Subject: Last Call:  (Path Computation Element Communication Protocol (PCEP) Extensions for Segment Routing (SR) Policy Candidate Paths) to Proposed Standard


The IESG has received a request from the Path Computation Element WG (pce) to
consider the following document: - 'Path Computation Element Communication
Protocol (PCEP) Extensions for
  Segment Routing (SR) Policy Candidate Paths'
  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
last-call@ietf.org mailing lists by 2024-11-11. 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


  Segment Routing (SR) allows a node to steer a packet flow along any
  path.  SR Policy is an ordered list of segments (i.e., instructions)
  that represent a source-routed policy.  Packet flows are steered into
  an SR Policy on a node where it is instantiated called a headend
  node.  An SR Policy is made of one or more candidate paths.

  This document specifies the Path Computation Element Communication
  Protocol (PCEP) extension to signal candidate paths of the SR Policy.
  Additionally, this document updates RFC 8231 to allow stateful bring
  up of an SR Label Switched Path (LSP), without using the path
  computation request and reply messages.  This document is applicable
  to both Segment Routing over MPLS (SR-MPLS) and Segment Routing over
  IPv6 (SRv6).




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-pce-segment-routing-policy-cp/



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

# Document Shepherd Write-Up for Group Documents

*This version is dated 4 July 2022.*

Thank you for your service as a document shepherd. Among the responsibilities is
answering the questions in this write-up to give helpful context to Last Call
and Internet Engineering Steering Group ([IESG][1]) reviewers, and your
diligence in completing it is appreciated. The full role of the shepherd is
further described in [RFC 4858][2]. You will need the cooperation of the authors
and editors to complete these checks.

Note that some numbered items contain multiple related questions; please be sure
to answer all of them.

## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

It represents a strong concurrence of a few with no objections from others.

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

WG debated the use of a fixed value for association ID (and innovative use of Extended Association ID) but converged on the current solution to handle any possibility of a race condition in case of multiple PCE.

3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
  so, please summarize 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

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

The Implementation Status section notes that there are 2 known implementations at the least.

## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.

No

6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

No

7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation? If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time? Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

No

8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

N/A

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

This document has been reviewed by the chair. The document is clear and ready
to be shipped.

10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?

N/A

11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])? Why is this the proper type
    of RFC? Do all Datatracker state attributes correctly reflect this intent?

Proposed Standard
This I-D defines a protocol extension and thus the standards track makes sense.
All attributes in Datatracker are set correctly.

12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]? To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.

There are no IPRs. Poll was conducted during adoption and WGLC.

13. Has each author, editor, and contributor shown their willingness to be
    listed as such? If the total number of authors and editors on the front page
    is greater than five, please provide a justification.


Yes

14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)

None

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].

No

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?

N/A

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.

None

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?

None

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.

This document updates RFC 8231, it is captured in the metadata and abstract.

20. 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 aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).

The IANA section is consistent with the document's body and has been reviewed.
Some coordination is needed with draft-ietf-idr-bgp-ls-sr-policy as both documents are trying to create the same registry. Whichever document gets to the IESG approval first keeps the registry and the other would need to update the IANA section. 


21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.

https://www.ietf.org/archive/id/draft-ietf-pce-segment-routing-policy-cp-17.html#section-6.5
The guidance is the same as RFC 9256.

[1]: https://www.ietf.org/about/groups/iesg/
[2]: https://www.rfc-editor.org/rfc/rfc4858.html
[3]: https://www.rfc-editor.org/rfc/rfc7942.html
[4]: https://wiki.ietf.org/group/ops/yang-review-tools
[5]: https://www.rfc-editor.org/rfc/rfc8342.html
[6]: https://wiki.ietf.org/group/iesg/ExpertTopics
[7]: https://www.rfc-editor.org/info/bcp79
[8]: https://www.ietf.org/tools/idnits/
[9]: https://www.rfc-editor.org/rfc/rfc3967.html
[10]: https://www.rfc-editor.org/info/bcp97
[11]: https://www.rfc-editor.org/rfc/rfc8126.html
[12]: https://www.rfc-editor.org/rfc/rfc2026.html#section-5
[13]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.1
[14]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.2
[15]: https://authors.ietf.org/en/content-guidelines-overview
[16]: https://www.ietf.org/about/groups/iesg/statements/normative-informative-references/
[17]: https://datatracker.ietf.org/doc/downref/

# Document Shepherd Write-Up for Group Documents

*This version is dated 4 July 2022.*

Thank you for your service as a document shepherd. Among the responsibilities is
answering the questions in this write-up to give helpful context to Last Call
and Internet Engineering Steering Group ([IESG][1]) reviewers, and your
diligence in completing it is appreciated. The full role of the shepherd is
further described in [RFC 4858][2]. You will need the cooperation of the authors
and editors to complete these checks.

Note that some numbered items contain multiple related questions; please be sure
to answer all of them.

## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

It represents a strong concurrence of a few with no objections from others.

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

WG debated the use of a fixed value for association ID (and innovative use of Extended Association ID) but converged on the current solution to handle any possibility of a race condition in case of multiple PCE.

3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
  so, please summarize 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

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

The Implementation Status section notes that there are 2 known implementations at the least.

## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.

No

6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

No

7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation? If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time? Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

No

8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

N/A

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

This document has been reviewed by the chair. The document is clear and ready
to be shipped.

10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?

N/A

11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])? Why is this the proper type
    of RFC? Do all Datatracker state attributes correctly reflect this intent?

Proposed Standard
This I-D defines a protocol extension and thus the standards track makes sense.
All attributes in Datatracker are set correctly.

12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]? To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.

There are no IPRs. Poll was conducted during adoption and WGLC.

13. Has each author, editor, and contributor shown their willingness to be
    listed as such? If the total number of authors and editors on the front page
    is greater than five, please provide a justification.


Yes

14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)

None

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].

No

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?

N/A

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.

None

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?

None

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.

This document updates RFC 8231, it is captured in the metadata and abstract.

20. 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 aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).

The IANA section is consistent with the document's body and has been reviewed.
Some coordination is needed with draft-ietf-idr-bgp-ls-sr-policy as both documents are trying to create the same registry. Whichever document gets to the IESG approval first keeps the registry and the other would need to update the IANA section. 


21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.

https://www.ietf.org/archive/id/draft-ietf-pce-segment-routing-policy-cp-17.html#section-6.5
The guidance is the same as RFC 9256.

[1]: https://www.ietf.org/about/groups/iesg/
[2]: https://www.rfc-editor.org/rfc/rfc4858.html
[3]: https://www.rfc-editor.org/rfc/rfc7942.html
[4]: https://wiki.ietf.org/group/ops/yang-review-tools
[5]: https://www.rfc-editor.org/rfc/rfc8342.html
[6]: https://wiki.ietf.org/group/iesg/ExpertTopics
[7]: https://www.rfc-editor.org/info/bcp79
[8]: https://www.ietf.org/tools/idnits/
[9]: https://www.rfc-editor.org/rfc/rfc3967.html
[10]: https://www.rfc-editor.org/info/bcp97
[11]: https://www.rfc-editor.org/rfc/rfc8126.html
[12]: https://www.rfc-editor.org/rfc/rfc2026.html#section-5
[13]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.1
[14]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.2
[15]: https://authors.ietf.org/en/content-guidelines-overview
[16]: https://www.ietf.org/about/groups/iesg/statements/normative-informative-references/
[17]: https://datatracker.ietf.org/doc/downref/

# Document Shepherd Write-Up for Group Documents

*This version is dated 4 July 2022.*

Thank you for your service as a document shepherd. Among the responsibilities is
answering the questions in this write-up to give helpful context to Last Call
and Internet Engineering Steering Group ([IESG][1]) reviewers, and your
diligence in completing it is appreciated. The full role of the shepherd is
further described in [RFC 4858][2]. You will need the cooperation of the authors
and editors to complete these checks.

Note that some numbered items contain multiple related questions; please be sure
to answer all of them.

## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

It represents a strong concurrence of a few with no objections from others.

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

WG debated the use of a fixed value for association ID (and innovative use of Extended Association ID) but converged on the current solution to handle any possibility of a race condition in case of multiple PCE.

3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
  so, please summarize 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

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

The Implementation Status section notes that there are 2 known implementations at the least.

## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.

No

6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

No

7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation? If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time? Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

No

8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

N/A

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

This document has been reviewed by the chair. The document is clear and ready
to be shipped.

10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?

N/A

11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])? Why is this the proper type
    of RFC? Do all Datatracker state attributes correctly reflect this intent?

Proposed Standard
This I-D defines a protocol extension and thus the standards track makes sense.
All attributes in Datatracker are set correctly.

12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]? To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.

There are no IPRs. Poll was conducted during adoption and WGLC.

13. Has each author, editor, and contributor shown their willingness to be
    listed as such? If the total number of authors and editors on the front page
    is greater than five, please provide a justification.


Yes

14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)

None

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].

No

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?

N/A

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.

None

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?

None

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.

None

20. 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 aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).

The IANA section is consistent with the document's body and has been reviewed.
Some coordination is needed with draft-ietf-idr-bgp-ls-sr-policy as both documents are trying to create the same registry. Whichever document gets to the IESG approval first keeps the registry and the other would need to update the IANA section. 


21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.

https://www.ietf.org/archive/id/draft-ietf-pce-segment-routing-policy-cp-17.html#section-6.5
The guidance is the same as RFC 9256.

[1]: https://www.ietf.org/about/groups/iesg/
[2]: https://www.rfc-editor.org/rfc/rfc4858.html
[3]: https://www.rfc-editor.org/rfc/rfc7942.html
[4]: https://wiki.ietf.org/group/ops/yang-review-tools
[5]: https://www.rfc-editor.org/rfc/rfc8342.html
[6]: https://wiki.ietf.org/group/iesg/ExpertTopics
[7]: https://www.rfc-editor.org/info/bcp79
[8]: https://www.ietf.org/tools/idnits/
[9]: https://www.rfc-editor.org/rfc/rfc3967.html
[10]: https://www.rfc-editor.org/info/bcp97
[11]: https://www.rfc-editor.org/rfc/rfc8126.html
[12]: https://www.rfc-editor.org/rfc/rfc2026.html#section-5
[13]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.1
[14]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.2
[15]: https://authors.ietf.org/en/content-guidelines-overview
[16]: https://www.ietf.org/about/groups/iesg/statements/normative-informative-references/
[17]: https://datatracker.ietf.org/doc/downref/

# Document Shepherd Write-Up for Group Documents

*This version is dated 4 July 2022.*

Thank you for your service as a document shepherd. Among the responsibilities is
answering the questions in this write-up to give helpful context to Last Call
and Internet Engineering Steering Group ([IESG][1]) reviewers, and your
diligence in completing it is appreciated. The full role of the shepherd is
further described in [RFC 4858][2]. You will need the cooperation of the authors
and editors to complete these checks.

Note that some numbered items contain multiple related questions; please be sure
to answer all of them.

## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

It represents a strong concurrence of a few with no objections from others.

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

WG debated the use of a fixed value for association ID (and instead innovative use of Extended Association ID) but converged on this solution to handle any possibility of a race condition in case of multiple PCE.

3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
  so, please summarize 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

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

The Implementation Status section notes that there are 2 known implementations at the least.

## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.

No

6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

No

7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation? If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time? Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

No

8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

N/A

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

This document has been reviewed by the chair. The document is clear and ready
to be shipped.

10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?

N/A

11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])? Why is this the proper type
    of RFC? Do all Datatracker state attributes correctly reflect this intent?

Proposed Standard
This I-D defines a protocol extension and thus the standards track makes sense.
All attributes in Datatracker are set correctly.

12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]? To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.

There are no IPRs. Poll was conducted during adoption and WGLC.

13. Has each author, editor, and contributor shown their willingness to be
    listed as such? If the total number of authors and editors on the front page
    is greater than five, please provide a justification.


Yes

14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)

None

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].

No

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?

N/A

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.

None

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?

None

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.

None

20. 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 aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).

The IANA section is consistent with the document's body and has been reviewed.
Some coordination is needed with draft-ietf-idr-bgp-ls-sr-policy as both documents are trying to create the same registry. Whichever document gets to the IESG approval first keeps the registry and the other would need to update the IANA section. 


21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.

https://www.ietf.org/archive/id/draft-ietf-pce-segment-routing-policy-cp-17.html#section-6.5
The guidance is the same as RFC 9256.

[1]: https://www.ietf.org/about/groups/iesg/
[2]: https://www.rfc-editor.org/rfc/rfc4858.html
[3]: https://www.rfc-editor.org/rfc/rfc7942.html
[4]: https://wiki.ietf.org/group/ops/yang-review-tools
[5]: https://www.rfc-editor.org/rfc/rfc8342.html
[6]: https://wiki.ietf.org/group/iesg/ExpertTopics
[7]: https://www.rfc-editor.org/info/bcp79
[8]: https://www.ietf.org/tools/idnits/
[9]: https://www.rfc-editor.org/rfc/rfc3967.html
[10]: https://www.rfc-editor.org/info/bcp97
[11]: https://www.rfc-editor.org/rfc/rfc8126.html
[12]: https://www.rfc-editor.org/rfc/rfc2026.html#section-5
[13]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.1
[14]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.2
[15]: https://authors.ietf.org/en/content-guidelines-overview
[16]: https://www.ietf.org/about/groups/iesg/statements/normative-informative-references/
[17]: https://datatracker.ietf.org/doc/downref/