PCEP Extensions for sid verification for SR-MPLS
draft-chen-pce-sr-mpls-sid-verification-08

PCE                                                              R. Chen
Internet-Draft                                           ZTE Corporation
Intended status: Standards Track                                S. Sidor
Expires: 25 August 2024                              Cisco Systems, Inc.
                                                                  C. Zhu
                                                         ZTE Corporation
                                                                A. Tokar
                                                            M. Koldychev
                                                     Cisco Systems, Inc.
                                                        22 February 2024

            PCEP Extensions for sid verification for SR-MPLS
               draft-chen-pce-sr-mpls-sid-verification-08

Abstract

   This document defines a new flag for indicating the headend is
   explicitly requested to verify SID(s) by the PCE.

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   This Internet-Draft will expire on 25 August 2024.

Copyright Notice

   Copyright (c) 2024 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Requirements Language . . . . . . . . . . . . . . . . . .   2
   2.  SID verification flag(V-Flag) . . . . . . . . . . . . . . . .   3
     2.1.  V-Flag in SR-ERO Subobject  . . . . . . . . . . . . . . .   3
     2.2.  V-Flag in SR-RRO Subobject  . . . . . . . . . . . . . . .   3
     2.3.  SID verification Processing . . . . . . . . . . . . . . .   3
   3.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   3
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   3
     4.1.  SR-ERO Subobject  . . . . . . . . . . . . . . . . . . . .   3
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   4
   6.  Normative References  . . . . . . . . . . . . . . . . . . . .   4
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   4

1.  Introduction

   [RFC9256] describes the "SID verification" bit usage.  SID
   verification is performed when the headend is explicitly requested to
   verify SID(s) by the controller via the signaling protocol used.
   Implementations MAY provide a local configuration option to enable
   verification on a global or per policy or per candidate path basis.

   [RFC8664] specifies extensions to the Path Computation Element
   Communication Protocol (PCEP) that allow a stateful PCE to compute
   and initiate Traffic-Engineering (TE) paths, as well as a Path
   Computation Client (PCC) to request a path subject to certain
   constraints and optimization criteria in SR networks.

   This document defines a new flag for indicating the headend is
   explicitly requested to verify SID(s) by the PCE.

1.1.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in BCP
   14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

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2.  SID verification flag(V-Flag)

2.1.  V-Flag in SR-ERO Subobject

   Section 4.3.1 in Path Computation Element Communication Protocol
   (PCEP) Extensions for Segment Routing [RFC8664] describes a new ERO
   subobject referred to as the "SR-ERO subobject" to carry a SID and/or
   NAI information.  A new flag is proposed in this doucument in the SR-
   ERO Subobject [RFC8664] for indicating the pcc is explicitly
   requested to verify SID(s) by the PCE.

   V（1bit。TBD）: When the V-Flag is set then PCC MUST consider the "SID
   verification".

2.2.  V-Flag in SR-RRO Subobject

   The format of the SR-RRO subobject is the same as that of the SR-ERO
   subobject, but without the L-Flag, per [RFC8664].

   The V flag has no meaning in the SR-RRO and is ignored on receipt at
   the PCE.

2.3.  SID verification Processing

   On receiving an SR-ERO with the V-flag is set, a PCC MUST verify
   SID(s) as described in Section 5.1 in [RFC9256].

   If a PCC "Verification fails" for a SID, it MUST report this error by
   including the LSP-ERROR-CODE TLV with LSP error-value "SID
   Verification fails" in the LSP object in the PCRpt message to the
   PCE.

3.  Acknowledgements

   We would like to thank Dhruv Dhody and John Scudder for their useful
   comments and suggestions.

4.  IANA Considerations

4.1.  SR-ERO Subobject

   This document defines a new bit value in the sub-registry "SR-ERO
   Flag Field" in the "Path Computation Element Protocol (PCEP) Numbers"
   registry.

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            Bit     Name                         Reference
            ---   -----------------------      --------------
            TBD     SID verification(V)          This document

                                  Figure 1

5.  Security Considerations

   TBD.

6.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [RFC8664]  Sivabalan, S., Filsfils, C., Tantsura, J., Henderickx, W.,
              and J. Hardwick, "Path Computation Element Communication
              Protocol (PCEP) Extensions for Segment Routing", RFC 8664,
              DOI 10.17487/RFC8664, December 2019,
              <https://www.rfc-editor.org/info/rfc8664>.

   [RFC9256]  Filsfils, C., Talaulikar, K., Ed., Voyer, D., Bogdanov,
              A., and P. Mattes, "Segment Routing Policy Architecture",
              RFC 9256, DOI 10.17487/RFC9256, July 2022,
              <https://www.rfc-editor.org/info/rfc9256>.

Authors' Addresses

   Ran Chen
   ZTE Corporation
   Nanjing
   China
   Email: chen.ran@zte.com.cn

   Samuel Sidor
   Cisco Systems, Inc.
   Email: ssidor@cisco.com

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   Chun Zhu
   ZTE Corporation
   Nanjing
   China
   Email: zhu.chun1@zte.com.cn

   Alex Tokar
   Cisco Systems, Inc.
   Email: atokar@cisco.com

   Mike Koldychev
   Cisco Systems, Inc.
   Email: mkoldych@cisco.com

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