SPRING Working Group                                            W. Cheng
Internet-Draft                                                  W. Jiang
Intended status: Standards Track                            China Mobile
Expires: 23 April 2024                                           R. Chen
                                                                 D. Zhao
                                                         ZTE Corporation
                                                                  C. Lin
                                                    New H3C Technologies
                                                         21 October 2023


                  Resource Guarantee for SRv6 Policies
          draft-cheng-spring-srv6-policy-resource-gurantee-02

Abstract

   This document defines a new SRv6 Endpoint behavior which can be used
   to associate with a set of network resource partition (e.g.
   bandwidth, buffer and queue resources ) Programming, called End.NRP.
   By using the End.NRP SID to build its segment list , the SRv6 policy
   has the capability to program network resources and achieve strict
   SLA guarantees.

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
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   Internet-Drafts are draft documents valid for a maximum of six months
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   This Internet-Draft will expire on 23 April 2024.

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.



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   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
     1.1.  Requirements Language . . . . . . . . . . . . . . . . . .   3
     1.2.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  End.NRP Behavior  . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Use Cases for End.NRP behavior  . . . . . . . . . . . . . . .   4
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .   6
   5.  Implementation Status . . . . . . . . . . . . . . . . . . . .   6
     5.1.  ZTE Corp  . . . . . . . . . . . . . . . . . . . . . . . .   7
     5.2.  New H3C Technologies  . . . . . . . . . . . . . . . . . .   8
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   8
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   8
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .   8
     7.2.  Informative References  . . . . . . . . . . . . . . . . .  10
   Appendix A.  Acknowledgements . . . . . . . . . . . . . . . . . .  10
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  10

1.  Introduction

   The concept of Network Resource Partition is introduced in
   [I-D.ietf-teas-ietf-network-slices].  A Network Resource Partition
   (NRP) is a set of network resources that are allocated from the
   underlay network to carry a specific set of network traffic and meet
   the required SLOs and SLEs.

   Segment Routing (SR) [RFC8402] leverages the source routing paradigm.
   An ingress node steers a packet through an ordered list of
   instructions, called "segments".  Each one of these instructions
   represents a function to be called at a specific location in the
   network.  A function is locally defined on the node where it is
   executed and may range from simply moving forward in the segment list
   to any complex user-defined behavior.

   SR Policy is an ordered list of segments (i.e. instructions) that
   represent a source-routed policy.  The packets steered into an SR
   Policy have an ordered list of segments associated with that SR
   Policy.







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   Since the SRv6 Endpoint behavior defined in [RFC8986] are not
   associated with a set of network resource partition of the interface
   for slices/slice aggregate(e.g.End.X just forwards to an endpoint
   with cross-connect to a 'layer-3 adjacency' or L2 bundles).
   Therefore, SRv6 policies can't achieve strict SLA guarantees.

   [I-D.ietf-spring-resource-aware-segments]extends the SR paradigm by
   associating SIDs with network resource attributes.  On the basis of
   [I-D.ietf-spring-resource-aware-segments], this document defines a
   new SRv6 Endpoint behavior which can be used to associate with a set
   of network resource partition (e.g. bandwidth, buffer and queue
   resources ) Programming, called End.NRP.  By using the End.NRP SID to
   build its segment list , the SRv6 policy has the capability to
   program network resources and achieve strict SLA guarantees.

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.

1.2.  Terminology

   The following terminology is used in this document:

   *  NRP: Network Resource Partition

   *  PSP:Penultimate Segment Pop

   *  SLA: Service Level Agreement

   *  SR:Segment Routing

   *  SRv6:The instantiation of SR on the IPv6 data plane.

   *  USD: Ultimate Segment Decapsulation

   *  USP: Ultimate Segment Pop

2.  End.NRP Behavior

   This section defines a new SRv6 Endpoint behavior which can be used
   to associate with a set of snetwork resource partition (e.g.
   bandwidth, buffer and queue resources ) Programming, called End.NRP.
   The End.NRP is a variant of the End.X behavior defined in [RFC8986].




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   Any SID instance of End.NRP behavior is associated with two sets: J1
   and J2.

   J1: one or more L3 adjacencies or L2 bundles
   J2: NRP of J1

   When N receives a packet destined to S and S is a local End.NRP SID,
   the line S15 from the End processing defined in [RFC8986] is replaced
   by the following:

   S15. Submit the packet to the IPv6 module for transmission to
        the new destination via a member of J1, using the NRP
        identified by J2

   This End.NRP SID SHOULD support the Penultimate Segment Pop (PSP) of
   the SRH, Ultimate Segment Pop (USP) of the SRH, and Ultimate Segment
   Decapsulation (USD) flavors defined in [RFC8986] either individually
   or in combinations.  The SRH processing of the End.NRP behavior with
   PSP, USP, and USD is the same as [RFC8986].

   This End.NRP SIDs can be allocated either by a centralized network
   controller or by the network nodes, and the End.NRP behavior MAY be
   announced using IGP or BGP-LS.  The detailed protocol extension will
   be described in a separate document.

3.  Use Cases for End.NRP behavior

   This section describes possible procedures for the End.NRP behavior.

   A group of End.NRP SIDs SHOULD be allocated for the set of network
   resources associated with the SRv6 Policies, so that different
   End.NRP SIDs SHOULD be used to steer service traffic into different
   set of link resources (e.g. bandwidth, buffer and queue resources) in
   packet forwarding.

   Below is the possible procedures:

   1.  The controller get the topology information, calculate the SR
       Policy path based on SLA.

   2.  The controller cooperates with the network nodes to complete
       resource reservation and the End.NRP SID allocation along the SR
       Policy path.

   3.  The controller use the End.NRP SID to build the SID list for the
       explicit path.





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   4.  Then the controller inform the headend the resource guaranteed
       path by various means including: via BGP
       [I-D.ietf-idr-segment-routing-te-policy], configuration or PCEP
       [RFC8664] [I-D.ietf-pce-segment-routing-policy-cp].


         SRv6 Policy1 from PE1 to PE2
         segment list <End.NRP11, End.NRP12, End.NRP13>

         SRv6 Policy2 from PE1 to PE2
         segment list <End.NRP21, End.NRP22, End.NRP23>

                                End.NRP12
                                End.NRP22
                               * * * * * *
                              P1-----------P2
                           */*|* * * * * * |\ * *
                          */* |            | \ * *
         CE11-----   End.NRP11|            |End.NRP13  ------ CE12
                  \  End.NRP21|            |End.NRP23 /
                   \   */ *   |            |    \* * /
                    PE1 \     |            |      PE2
                   /     \    |            |    /    \
                  /       \   |            |   /      \------ CE2
         CE21------        \  |            |  /
                            \ |            | /
                             P3------------P4

                                  Figure 1

   Figure 1 shows an example for the End.NRP behavior.

   As shown in Figure 1, there are two customers with different leased
   line requirements from PE1 to PE2:

      leased line1 : 1G BandWidth with strict SLA guarantee.

      leased line2 : 2G BandWidth with strict SLA guarantee.

   Below is the possible procedures:

   1.  The controller get the topology information, calculate the SRv6
       Policy 1 and SRv6 Policy 2 based on SLA.








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   2.  The controller cooperates with the network nodes to complete
       resource reservation and the End.NRP SID allocation along the
       SRv6 Policy1 and SRv6 Policy 2.  Taking the interface PE1-P1 of
       SRv6 node PE1 along the SRv6 Policy 1 as an example, two
       different NRPs(e.g. two dedicated queues) are partitioned from
       the network resources of the physical link PE1-P1 (GE1/0/0).

       *  The NRP(Queue1:1G BW)of link PE1- P1 is reserved and
          associated with End.NRP11.

       *  The NRP(Queue2:2G BW)of link PE1- P1 is reserved and
          associated with End.NRP21.

   3.  The controller uses the End.NRP11, End.NRP12, and End.NRP13 to
       build the SID list for the SRv6 Policy1 and use the End.NRP21,
       End.NRP22, and End.NRP23 to build the SID list for the SRv6
       Policy 2.

   4.  Then the controller inform the headend the segment list of SRv6
       Policy 1 and the segment list of SRv6 Policy 2 by various means
       including: via BGP [I-D.ietf-idr-segment-routing-te-policy],
       configuration or PCEP [RFC8664]
       [I-D.ietf-pce-segment-routing-policy-cp].

   The traffic from customer1 and customer2 will be forwarded to PE2
   through the NRPs previously reserved for each hop link on the path of
   SRv6 Policy1 and SRv6 Policy2 respectively, thus Customer 1 and
   Customer 2 are provided with end-to-end 1G bandwidth resources and 2G
   bandwidth resources respectively, and private line services are
   guaranteed by strict SLAs.

4.  Security Considerations

   The security requirements and mechanisms described in [RFC8402],
   [RFC8754] and [RFC8986] also apply to this document.

   This document introduces a new SRv6 Endpoint behavior for
   implementation on the nodes support network resource partition in the
   network.  As such, this document does not introduce any new security
   considerations.

5.  Implementation Status

   [Note to the RFC Editor - remove this section before publication, as
   well as remove the reference to [RFC7942].






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   This section records the status of known implementations of the
   protocol defined by this specification at the time of posting of this
   Internet-Draft, and is based on a proposal described in [RFC7942].
   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.

   According to [RFC7942], "this will allow reviewers and working groups
   to assign due consideration to documents that have the benefit of
   running code, which may serve as evidence of valuable experimentation
   and feedback that have made the implemented protocols more mature.
   It is up to the individual working groups to use this information as
   they see fit".

5.1.  ZTE Corp

   *  Organization: ZTE Corporation.

   *  Implementation: ZTE's M6000 Series Routers implementation of
      END.NRP [ZTE-IMP].

   *  Description: The feature of SRv6 END.NRP has been implemented in
      ZTE M6000 series routers and follows the definition and mechanism
      as defined in section 2 and Section 3 including all the "MUST" and
      "SHOULD" clauses.

   *  Maturity Level: Beta

   *  Coverage: ALL, section 2 and use case section 3.

   *  Version: Draft-02

   *  Licensing: N/A

   *  Implementation experience: Nothing specific.

   *  Contact: zhu.xiaolong@zte.com.cn

   *  Last updated: October 21, 2023






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5.2.  New H3C Technologies

   *  Organization: New H3C Technologies.

   *  Implementation: H3C CR16000, CR19000 series routers
      implementation.

   *  Description: Section 2 and Section 3 including all the "MUST" and
      "SHOULD" clauses have been implemented in above mentioned New H3C
      Products for testing.

   *  Maturity Level: Beta

   *  Coverage: ALL, section 2 and use case section 3.

   *  Version: Draft-02

   *  Licensing: N/A

   *  Implementation experience: Nothing specific.

   *  Contact: linchangwang.04414@h3c.com

   *  Last updated: October 21, 2023

6.  IANA Considerations

   The document defines a new SRv6 Endpoint behavior called End.NRP.

   This I-D requests the IANA to allocate, within the "SRv6 Endpoint
   Behaviors" sub-registry belonging to the top-level "Segment-routing
   with IPv6 dataplane (SRv6) Parameters" registry, the following
   allocations:

   Value              Endpoint Behavior               Reference
   ---------------------------------------------------------------
   TBD1                End.NRP                      [This.ID]


7.  References

7.1.  Normative References









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   [I-D.ietf-idr-segment-routing-te-policy]
              Previdi, S., Filsfils, C., Talaulikar, K., Mattes, P., and
              D. Jain, "Advertising Segment Routing Policies in BGP",
              Work in Progress, Internet-Draft, draft-ietf-idr-segment-
              routing-te-policy-25, 26 September 2023,
              <https://datatracker.ietf.org/doc/html/draft-ietf-idr-
              segment-routing-te-policy-25>.

   [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-
              ietf-pce-segment-routing-policy-cp-12, 24 July 2023,
              <https://datatracker.ietf.org/doc/html/draft-ietf-pce-
              segment-routing-policy-cp-12>.

   [I-D.ietf-spring-resource-aware-segments]
              Dong, J., Bryant, S., Miyasaka, T., Zhu, Y., Qin, F., Li,
              Z., and F. Clad, "Introducing Resource Awareness to SR
              Segments", Work in Progress, Internet-Draft, draft-ietf-
              spring-resource-aware-segments-07, 31 May 2023,
              <https://datatracker.ietf.org/doc/html/draft-ietf-spring-
              resource-aware-segments-07>.

   [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>.

   [RFC7942]  Sheffer, Y. and A. Farrel, "Improving Awareness of Running
              Code: The Implementation Status Section", BCP 205,
              RFC 7942, DOI 10.17487/RFC7942, July 2016,
              <https://www.rfc-editor.org/info/rfc7942>.

   [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>.

   [RFC8402]  Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L.,
              Decraene, B., Litkowski, S., and R. Shakir, "Segment
              Routing Architecture", RFC 8402, DOI 10.17487/RFC8402,
              July 2018, <https://www.rfc-editor.org/info/rfc8402>.

   [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>.



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   [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>.

   [RFC8986]  Filsfils, C., Ed., Camarillo, P., Ed., Leddy, J., Voyer,
              D., Matsushima, S., and Z. Li, "Segment Routing over IPv6
              (SRv6) Network Programming", RFC 8986,
              DOI 10.17487/RFC8986, February 2021,
              <https://www.rfc-editor.org/info/rfc8986>.

7.2.  Informative References

   [I-D.ietf-teas-ietf-network-slices]
              Farrel, A., Drake, J., Rokui, R., Homma, S., Makhijani,
              K., Contreras, L. M., and J. Tantsura, "A Framework for
              Network Slices in Networks Built from IETF Technologies",
              Work in Progress, Internet-Draft, draft-ietf-teas-ietf-
              network-slices-25, 14 September 2023,
              <https://datatracker.ietf.org/doc/html/draft-ietf-teas-
              ietf-network-slices-25>.

   [ZTE-IMP]  "ZTE M6000-S Routers", 21 October 2023,
              <https://www.zte.com.cn/china/product_index/ip_network/
              item02/zxr10-m6000-s/zxr10_m6000_s.html>.

Appendix A.  Acknowledgements

   TBD.

Authors' Addresses

   Weiqiang Cheng
   China Mobile
   China
   Email: chengweiqiang@chinamobile.com


   Wenying Jiang
   China Mobile
   China
   Email: jiangwenying@chinamobile.com


   Ran Chen
   ZTE Corporation
   Nanjing
   China



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   Email: chen.ran@zte.com.cn


   Detao Zhao
   ZTE Corporation
   Nanjing
   China
   Email: zhao.detao@zte.com.cn


   Changwang Lin
   New H3C Technologies
   China
   Email: linchangwang.04414@h3c.com





































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