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Traffic Steering using BGP FlowSpec with SR Policy
draft-ietf-idr-ts-flowspec-srv6-policy-03

Document Type Active Internet-Draft (idr WG)
Authors Jiang Wenying , Yisong Liu , Shunwan Zhuang , Gyan Mishra , Shuanglong Chen
Last updated 2024-03-20 (Latest revision 2023-06-16)
Replaces draft-jiang-idr-ts-flowspec-srv6-policy
RFC stream Internet Engineering Task Force (IETF)
Intended RFC status Informational
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Document shepherd Keyur Patel
Shepherd write-up Show Last changed 2023-09-08
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Send notices to shares@ndzh.com, keyur@arrcus.com
draft-ietf-idr-ts-flowspec-srv6-policy-03
Network Working Group                                           W. Jiang
Internet-Draft                                                    Y. Liu
Intended status: Informational                              China Mobile
Expires: 19 December 2023                                      S. Zhuang
                                                     Huawei Technologies
                                                               G. Mishra
                                             Verizon Communications Inc.
                                                                 S. Chen
                                                     Huawei Technologies
                                                            17 June 2023

           Traffic Steering using BGP FlowSpec with SR Policy
               draft-ietf-idr-ts-flowspec-srv6-policy-03

Abstract

   BGP Flow Specification (FlowSpec) [RFC8955] and [RFC8956] has been
   proposed to distribute BGP [RFC4271] FlowSpec NLRI to FlowSpec
   clients to mitigate (distributed) denial-of-service attacks, and to
   provide traffic filtering in the context of a BGP/MPLS VPN service.
   Recently, traffic steering applications in the context of SR-MPLS and
   SRv6 using FlowSpec also attract attention.  This document introduces
   the usage of BGP FlowSpec to steer packets into an SR Policy.

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 RFC 2119 [RFC2119] [RFC8174] when, and only when, they appear in
   all capitals, as shown here.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

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   This Internet-Draft will expire on 19 December 2023.

Copyright Notice

   Copyright (c) 2023 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents (https://trustee.ietf.org/
   license-info) in effect on the date of publication of this document.
   Please review these documents carefully, as they describe your rights
   and restrictions with respect to this document.  Code Components
   extracted from this document must include Revised BSD License text as
   described in Section 4.e of the Trust Legal Provisions and are
   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Definitions and Acronyms  . . . . . . . . . . . . . . . . . .   3
   3.  Operations  . . . . . . . . . . . . . . . . . . . . . . . . .   4
   4.  SR-MPLS Application Examples  . . . . . . . . . . . . . . . .   5
   5.  SRv6 Application Examples . . . . . . . . . . . . . . . . . .   6
   6.  Running Code  . . . . . . . . . . . . . . . . . . . . . . . .   8
     6.1.  Interop-test Status . . . . . . . . . . . . . . . . . . .   9
     6.2.  Deployment Status . . . . . . . . . . . . . . . . . . . .  10
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  10
   8.  Security Considerations . . . . . . . . . . . . . . . . . . .  10
   9.  Contributors  . . . . . . . . . . . . . . . . . . . . . . . .  10
   10. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  10
   11. References  . . . . . . . . . . . . . . . . . . . . . . . . .  11
     11.1.  Normative References . . . . . . . . . . . . . . . . . .  11
     11.2.  Informative References . . . . . . . . . . . . . . . . .  12
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  13

1.  Introduction

   SR-MPLS [RFC8660] forwards data packets using the source routing
   model.  The core idea of SR-MPLS is to divide a packet forwarding
   path into different segments, allocate segment identifiers (SIDs) to
   the segments, and encapsulate segment information into packets at the
   ingress of the path to guide packet forwarding.

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   Segment Routing IPv6 (SRv6) is a protocol designed to forward IPv6
   data packets on a network using the source routing model.  SRv6
   enables the ingress network device to add a segment routing header
   (SRH) [RFC8754] to an IPv6 packet and push an explicit IPv6 address
   stack into the SRH.  After receiving the packet, each transit node
   updates the IPv6 destination IP address in the packet and segment
   list to implement hop-by-hop forwarding.

   SR Policy (includes SR-MPLS and SRv6 Policy) [RFC9256] is a tunneling
   technology based on SR-MPLS and SRv6.  An SR Policy is a set of
   candidate paths consisting of one or more segment lists, that is,
   segment ID (SID) lists.  Each SID list identifies an end-to-end path
   from the source node to the destination node, instructing a network
   device to forward traffic through the path rather than the shortest
   path computed using an IGP.  The header of a packet steered into an
   SR Policy is augmented with an ordered list of segments associated
   with that SR Policy, so that other devices on the network can execute
   the instructions encapsulated into the list.

   The headend of an SR Policy may learn multiple candidate paths for an
   SR Policy.  Candidate paths may be learned via a number of different
   mechanisms, e.g., CLI, NetConf,
   PCEP[I-D.ietf-pce-segment-routing-policy-cp], or
   BGP[I-D.ietf-idr-segment-routing-te-policy].

   [RFC8955] and [RFC8956] define the BGP [RFC4271] Flow Specification
   (FlowSpec) that allows conveying flow specifications and traffic
   Action/Rules associated (rate- limiting, redirect, remark ...).  BGP
   Flow specifications are encoded within the MP_REACH_NLRI and
   MP_UNREACH_NLRI attributes[RFC4760].  Rules (Actions associated) are
   encoded in Extended Community attribute[RFC4360].  The BGP Flow
   Specification function allows BGP Flow Specification routes that
   carry traffic policies to be transmitted to BGP Flow Specification
   peers to steer traffic.

   This document proposes BGP flow specification usage that are used to
   steer data flow into an SR Policy as well as to indicate Tailend
   function for SRv6 scenarios.  This work is helpful for promoting the
   deployment of SR-MPLS and SRv6 networks.

2.  Definitions and Acronyms

   *  FlowSpec: Flow Specification

   *  SR: Segment Routing

   *  SR-MPLS: SR over the MPLS data plane

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   *  SRv6: SR over the IPv6 data plane

   *  SID: Segment Identifier

   *  SRH: Segment Routing Header

   *  TE: Traffic Engineering

   *  USD: Ultimate Segment Decapsulation

3.  Operations

   An SR Policy [RFC9256] is identified through the tuple <headend,
   color, endpoint>.  In the context of a specific headend, one may
   identify an SR Policy by the <color, endpoint> tuple.  The headend is
   the node where the SR Policy is instantiated/implemented.  The
   headend is specified as an IPv4 or IPv6 address and is expected to be
   unique in the domain.  The endpoint indicates the destination of the
   SR Policy.  The endpoint is specified as an IPv4 or IPv6 address and
   is expected to be unique in the domain.  The color is a 32-bit
   unsigned numerical value that associates with the SR policy, and it
   defines an application-level network Service Level Agreement (SLA)
   policy or intent.

   Assume one or multiple SR Policies are already setup/instantiated in
   the SR HeadEnd device.  In order to steer traffic into a specific SR
   Policy at the Headend, one can use the SR Color Extended community
   [RFC9012] and endpoint to map to a satisfying SR Policy, and steer
   the traffic into this specific SR Policy.

   [I-D.ietf-idr-flowspec-redirect-ip] defines the redirect to IPv4 and
   IPv6 Next-hop action.  The IPv4 next-hop address in the Flow-spec
   Redirect to IPv4 Extended Community can be used to specify the
   endpoint of the SR Policy, and the IPv6 next-hop address in the Flow-
   spec Redirect to IPv6 Extended Community[RFC5701] can be used to
   specify the endpoint of the SRv6 Policy.  When the packets reach the
   TailEnd device, some specific function information identifiers can be
   used to decide how to further process the flows in SRv6 scenarios.
   Several endpoint functions are already defined, e.g., End.DT6:
   Endpoint with decapsulation and IPv6 table lookup, and End.DX6:
   Endpoint with decapsulation and IPv6 cross-connect.  The BGP Prefix-
   SID defined in [RFC8669] is utilized to enable SRv6 VPN services
   [RFC9252].  SRv6 Services TLVs within the BGP Prefix-SID Attribute
   can be used to indicate the endpoint functions.

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   For SR-MPLS scenarios, this document proposes carrying the Color
   Extended Community and the Flow-spec Redirect to IPv4 Extended
   Community in the context of a Flowspec NLRI [RFC8955] [RFC8956] to an
   SR-MPLS Headend to steer traffic into one SR-MPLS Policy.

   For SRv6 scenarios, this document proposes carrying the Color
   Extended Community, the Flow-spec Redirect to IPv6 Extended Community
   and BGP Prefix-SID Attribute in the context of a Flowspec NLRI
   [RFC8955] [RFC8956] to an SRv6 Headend to steer traffic into one SRv6
   Policy, as well as to indicate specific Tailend functions.

   For the case where a FlowSpec route carries multiple Color Extend
   Communities, the Color Extended community with the highest numerical
   value will be given higher preference per the description in
   Section 8.4.1 of [RFC9256].

   The method proposed in this document supports load balancing to the
   tailend device.  To achieve that, the headend device CAN set up
   multiple paths in one SR Policy, and use a FlowSpec route to indicate
   the specific SR Policy.

4.  SR-MPLS Application Examples

   In following scenario, BGP FlowSpec Controller signals the filter
   rules, the Flow-spec Redirect to IPv4 action, and the policy color to
   the SR-MPLS HeadEnd device.

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      +------------+
      |  BGP FS    |
      | Controller |
      +------------+
         | FlowSpec route to HeadEnd:
         |   NLRI: Filter Rules
         |   Redirect to IPv4 Nexthop: TailEnd's Address
         |   Policy Color: C0
         |
         |          .-----.
         |         (       )
         V     .--(         )--.
   +-------+  (                 )  +-------+
   |       |_(  SR-MPLS Network  )_|       |
   |HeadEnd| ( ================> ) |TailEnd|
   +-------+  (SR List<S1,S2,S3>)  +-------+
               '--(         )--'
                   (       )
                    '-----'

         Figure 1: Steering the Traffic Flow into SR-MPLS Policy

   When the SR-MPLS HeadEnd device (as a FlowSpec client) receives such
   instructions from BGP FS Controller, it will steer the traffic flows
   matching the criteria in the FlowSpec route into the SR-MPLS Policy
   matching the tuple (Endpoint: TailEnd's Address, Color: C0).  And the
   packets of such traffic flows will be encapsulated with an MPLS stack
   using the SR List <S1, S2, S3> in the HeadEnd device, then send the
   packets to the TailEnd device along the path indicated by the SR
   list.

5.  SRv6 Application Examples

   In following scenario, BGP FlowSpec Controller signals the filter
   rules, the redirect to IPv6 Nexthop action, the policy color and the
   function information (SRv6 SID: Service_id_x) to the HeadEnd device.

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      +------------+
      |  BGP FS    |
      | Controller |
      +------------+
         | FlowSpec route to HeadEnd:
         |   NLRI: Filter Rules
         |   Redirect to IPv6 Nexthop: TailEnd's Address
         |   Policy Color: C1
         |   PrefixSID: Service_id_x
         |          .-----.
         |         (       )
         V     .--(         )--.
   +-------+  (                 )  +-------+
   |       |_( SRv6 Core Network )_|       |
   |HeadEnd| ( ================> ) |TailEnd|
   +-------+  (SR List<S1,S2,S3>)  +-------+
               '--(         )--'   Service SID: Service_id_x
                   (       )       (e.g.: End.DT4 or End.DT6 or others)
                    '-----'

         Figure 2: Steering the Traffic Flow into SRv6 Policy (Option 1)

   When the HeadEnd device (as a FlowSpec client) receives such
   instructions from BGP FS Controller, it will steer the traffic flows
   matching the criteria in the FlowSpec route into the SRv6 Policy
   matching the tuple (Endpoint: TailEnd's Address, Color: C1).  And the
   packets of such traffic flows will be encapsulated with an SRH
   (Segment Routing Header) using the SR List <S1, S2, S3,
   Service_id_x>.  When the packets reach to the TailEnd device, they
   will be further processed per the function denoted by the
   Service_id_x.

   When the HeadEnd device determines (with the help of SRv6 SID
   Structure) that the Service SID belongs to the same SRv6 Locator as
   the last SRv6 SID of the TailEnd device in the SRv6 Policy segment
   list, it MAY exclude that last SRv6 SID when steering the service
   flow.  For example, the effective segment list of the SRv6 Policy
   associated with SID list <S1, S2, S3> would be replaced with <S1, S2,
   Service_id_x>.

   If the last SRv6 SID (for example, we use S3 here) of the TailEnd
   device in the SRv6 Policy segment list is USD-flavored, an SRv6
   Service SID (e.g., End.DT4 or End.DT6) is not required when a BGP
   FlowSpec Controller sends the FlowSpec route to the HeadEnd device
   (as a FlowSpec client).

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      +------------+
      |  BGP FS    |
      | Controller |
      +------------+
         | FlowSpec route to HeadEnd:
         |   NLRI: Filter Rules
         |   Redirect to IPv6 Nexthop: TailEnd's Address
         |   Policy Color: C2
         |          .-----.
         |         (       )
         V     .--(         )--.
   +-------+  (                 )  +-------+
   |       |_( SRv6 Core Network )_|       |
   |HeadEnd| ( ================> ) |TailEnd|
   +-------+  (SR List<S1,S2,S3>)  +-------+
               '--(         )--'
                   (       )
                    '-----'
   Note: S3 MUST be a USD-flavored SRv6 SID of the TailEnd

         Figure 3: Steering the Traffic Flow into SRv6 Policy (Option 2)

   When the HeadEnd device (as a FlowSpec client) receives such
   instructions from a BGP FS Controller, it will steer the traffic
   flows matching the criteria in the Flowspec route into the SRv6
   Policy matching the tuple (Endpoint: TailEnd's Address, Color: C2).
   And the packets of such traffic flows will be encapsulated with an
   SRH (Segment Routing Header) using the SR List <S1, S2, S3>.  When
   the packets reach to the TailEnd device, they will be further
   processed per the function denoted by the USD-flavored SRv6 SID S3.

   For the cases of intra-AS and inter-AS traffic steering using this
   method, the usages of Flowspec Color Extended Community with BGP
   prefix SID are the same for both scenarios.  The difference lies
   between the local SRv6 policy configurations.  For the inter-domain
   case, the operator can configure an inter-domain SRv6 policy/path at
   the Headend device.  For the intra-domain case, the operator can
   configure an intra-domain SRv6 policy/path at the Headend device.

6.  Running Code

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6.1.  Interop-test Status

   This section records the status of known implementations of the
   protocol defined by this specification at the time of posting of this
   document.  The description of implementations in this section is
   intended to assist the IETF in its decision processes in progressing
   drafts to RFCs.  Please note that the listing of any individual
   implementation here does not imply endorsement by the IETF.
   Furthermore, no effort has been spent to verify the information
   presented here that was supplied by IETF contributors.  This is not
   intended as, and must not be construed to be, a catalog of available
   implementations or their features.  Readers are advised to note that
   other implementations may exist.

   The Traffic Steering using BGP FlowSpec with SR-MPLS / SRv6 Policy
   mechanism has been implemented on the following hardware devices,
   Network Operating System software, and SDN controllers.  They have
   also successfully participated in the series of joint
   interoperability testing events hosted by China Mobile from July 2021
   to October 2021.  The following hardware devices and Network
   Operating System software had successfully passed the
   interoperability testing (in alphabetical order).

   Routers:
   +---------+---------------+--------------------------------+
   | Vendors | Device Model  | Version                        |
   +---------+---------------+--------------------------------+
   | Huawei  | NE40-X8A      | NE40E V800R021C00SPC091T       |
   +---------+---------------+--------------------------------+
   | New H3C | CR16010H-FA   | Version 7.1.075, ESS 8305      |
   +---------+---------------+--------------------------------+
   | Ruijie  | RG-N8010-R    | N8000-R_RGOS 12.8(1)B08T1      |
   +---------+---------------+--------------------------------+
   | ZTE     | M6000-8S Plus | V5.00.10(5.60.5)               |
   +---------+---------------+--------------------------------+

   Controllers:
   +----------------+---------------+-------------------------+
   | Vendors        | Device Model  | Version                 |
   +----------------+---------------+-------------------------+
   | China Unitechs | I-T-E SC      | V1.3.6P3                |
   +----------------+---------------+-------------------------+
   | Huawei         | NCE-IP        | V100R021C00             |
   +----------------+---------------+-------------------------+
   | Ruijie         | RG-ONC-AIO-H  | RG-ION-WAN-CLOUD_2.00T1 |
   +----------------+---------------+-------------------------+
   | ZTE            | ZENIC ONE     | R22V16.21.20            |
   +----------------+---------------+-------------------------+

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6.2.  Deployment Status

   As of August 2022, this feature has been deployed on the IP backbone
   network of China Mobile.

7.  IANA Considerations

   No IANA actions are required for this document.

8.  Security Considerations

   This document does not change the security properties of SRv6 and
   BGP.

9.  Contributors

   The following people made significant contributions to this document:

   Yunan Gu
   Huawei Technologies
   Email: guyunan@huawei.com

   Haibo Wang
   Huawei Technologies
   Email: rainsword.wang@huawei.com

   Jie Dong
   Huawei Technologies
   Email: jie.dong@huawei.com

   Xue Yang
   China Mobile
   Email: yangxuewl@chinamobile.com

10.  Acknowledgements

   The authors would like to acknowledge the review and inputs from
   Jeffrey Haas, Susan Hares, Weiqiang Cheng, Kaliraj Vairavakkalai,
   Robin Li, Acee Lindem, Gunter Van De Velde, John Scudder, Rainbow Wu,
   Linda Dunbar, Gang Yan, Feng Yang, Wim Henderickx, Robert Raszuk,
   Ketan Talaulikar, Changwang Lin, Aijun Wang, Hao Li, Huaimo Chen,
   Sheng Fang, Yuanxiang Qiu, Ran Chen, Cheng Li, Zheng Zhang, Xuewei
   Wang, Yanrong Liang, Xuhui Cai, Haojie Wang, Lili Wang and Nan Geng.

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   Special thanks to Nat Kao, who suggested adding SR-MPLS use cases to
   this document.

   Special thanks to Donald E.  Eastlake, 3rd, who thoroughly reviewed
   the entire document and made many useful suggestions for improvement.

11.  References

11.1.  Normative References

   [I-D.ietf-idr-flowspec-redirect-ip]
              Uttaro, J., Haas, J., Texier, M., akarch@cisco.com, Ray,
              S., Simpson, A., and W. Henderickx, "BGP Flow-Spec
              Redirect to IP Action", Work in Progress, Internet-Draft,
              draft-ietf-idr-flowspec-redirect-ip-02, 5 February 2015,
              <https://datatracker.ietf.org/doc/html/draft-ietf-idr-
              flowspec-redirect-ip-02>.

   [I-D.ietf-idr-segment-routing-te-policy]
              Previdi, S., Filsfils, C., Talaulikar, K., Mattes, P.,
              Jain, D., and S. Lin, "Advertising Segment Routing
              Policies in BGP", Work in Progress, Internet-Draft, draft-
              ietf-idr-segment-routing-te-policy-20, 27 July 2022,
              <https://datatracker.ietf.org/doc/html/draft-ietf-idr-
              segment-routing-te-policy-20>.

   [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>.

   [RFC4271]  Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A
              Border Gateway Protocol 4 (BGP-4)", RFC 4271,
              DOI 10.17487/RFC4271, January 2006,
              <https://www.rfc-editor.org/info/rfc4271>.

   [RFC4360]  Sangli, S., Tappan, D., and Y. Rekhter, "BGP Extended
              Communities Attribute", RFC 4360, DOI 10.17487/RFC4360,
              February 2006, <https://www.rfc-editor.org/info/rfc4360>.

   [RFC4760]  Bates, T., Chandra, R., Katz, D., and Y. Rekhter,
              "Multiprotocol Extensions for BGP-4", RFC 4760,
              DOI 10.17487/RFC4760, January 2007,
              <https://www.rfc-editor.org/info/rfc4760>.

   [RFC5701]  Rekhter, Y., "IPv6 Address Specific BGP Extended Community
              Attribute", RFC 5701, DOI 10.17487/RFC5701, November 2009,
              <https://www.rfc-editor.org/info/rfc5701>.

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   [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>.

   [RFC8660]  Bashandy, A., Ed., Filsfils, C., Ed., Previdi, S.,
              Decraene, B., Litkowski, S., and R. Shakir, "Segment
              Routing with the MPLS Data Plane", RFC 8660,
              DOI 10.17487/RFC8660, December 2019,
              <https://www.rfc-editor.org/info/rfc8660>.

   [RFC8669]  Previdi, S., Filsfils, C., Lindem, A., Ed., Sreekantiah,
              A., and H. Gredler, "Segment Routing Prefix Segment
              Identifier Extensions for BGP", RFC 8669,
              DOI 10.17487/RFC8669, December 2019,
              <https://www.rfc-editor.org/info/rfc8669>.

   [RFC8955]  Loibl, C., Hares, S., Raszuk, R., McPherson, D., and M.
              Bacher, "Dissemination of Flow Specification Rules",
              RFC 8955, DOI 10.17487/RFC8955, December 2020,
              <https://www.rfc-editor.org/info/rfc8955>.

   [RFC8956]  Loibl, C., Ed., Raszuk, R., Ed., and S. Hares, Ed.,
              "Dissemination of Flow Specification Rules for IPv6",
              RFC 8956, DOI 10.17487/RFC8956, December 2020,
              <https://www.rfc-editor.org/info/rfc8956>.

   [RFC9012]  Patel, K., Van de Velde, G., Sangli, S., and J. Scudder,
              "The BGP Tunnel Encapsulation Attribute", RFC 9012,
              DOI 10.17487/RFC9012, April 2021,
              <https://www.rfc-editor.org/info/rfc9012>.

   [RFC9252]  Dawra, G., Ed., Talaulikar, K., Ed., Raszuk, R., Decraene,
              B., Zhuang, S., and J. Rabadan, "BGP Overlay Services
              Based on Segment Routing over IPv6 (SRv6)", RFC 9252,
              DOI 10.17487/RFC9252, July 2022,
              <https://www.rfc-editor.org/info/rfc9252>.

   [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>.

11.2.  Informative References

   [I-D.ietf-pce-segment-routing-policy-cp]
              Koldychev, M., Sivabalan, S., Barth, C., Peng, S., and H.
              Bidgoli, "PCEP extension to support Segment Routing Policy
              Candidate Paths", Work in Progress, Internet-Draft, draft-

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              ietf-pce-segment-routing-policy-cp-10, 21 April 2023,
              <https://datatracker.ietf.org/doc/html/draft-ietf-pce-
              segment-routing-policy-cp-10>.

   [RFC8754]  Filsfils, C., Ed., Dukes, D., Ed., Previdi, S., Leddy, J.,
              Matsushima, S., and D. Voyer, "IPv6 Segment Routing Header
              (SRH)", RFC 8754, DOI 10.17487/RFC8754, March 2020,
              <https://www.rfc-editor.org/info/rfc8754>.

Authors' Addresses

   Wenying Jiang
   China Mobile
   No.32 XuanWuMen West Street
   Beijing
   100053
   China
   Email: jiangwenying@chinamobile.com

   Yisong Liu
   China Mobile
   No.32 XuanWuMen West Street
   Beijing
   100053
   China
   Email: liuyisong@chinamobile.com

   Shunwan Zhuang
   Huawei Technologies
   Huawei Bld., No.156 Beiqing Rd.
   Beijing
   100095
   China
   Email: zhuangshunwan@huawei.com

   Gyan Mishra
   Verizon Communications Inc.
   13101 Columbia Pike
   Silver Spring, MD 20904,
   United States of America
   Email: gyan.s.mishra@verizon.com

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   Shuanglong Chen
   Huawei Technologies
   Huawei Bld., No.156 Beiqing Rd.
   Beijing
   100095
   China
   Email: chenshuanglong@huawei.com

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