\
Network Working Group                                              B. Wu
Internet-Draft                                                  D. Dhody
Intended status: Standards Track                     Huawei Technologies
Expires: 3 August 2022                                          Y. Cheng
                                                            China Unicom
                                                         30 January 2022


         A YANG Data Model for Network Resource Partition (NRP)
                       draft-wd-teas-nrp-yang-00

Abstract

   This document defines a YANG data model for managing Network Resource
   Partition (NRP) topologies and associated resource allocation.  The
   model can be used for the realization of IETF network slice services.

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
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   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."

   This Internet-Draft will expire on 3 August 2022.

Copyright Notice

   Copyright (c) 2022 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.




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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   2
     2.1.  Tree Diagrams . . . . . . . . . . . . . . . . . . . . . .   3
   3.  NRP Modelling Consideration . . . . . . . . . . . . . . . . .   3
     3.1.  NRP Model Usage example . . . . . . . . . . . . . . . . .   5
     3.2.  NRP Modeling Design . . . . . . . . . . . . . . . . . . .   6
   4.  Description of NRP YANG Module  . . . . . . . . . . . . . . .   9
   5.  NRP Yang Module Tree  . . . . . . . . . . . . . . . . . . . .  10
   6.  NRP Yang Module . . . . . . . . . . . . . . . . . . . . . . .  11
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .  20
   8.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  21
   9.  Contributor . . . . . . . . . . . . . . . . . . . . . . . . .  21
   10. References  . . . . . . . . . . . . . . . . . . . . . . . . .  22
     10.1.  Normative References . . . . . . . . . . . . . . . . . .  22
     10.2.  Informative References . . . . . . . . . . . . . . . . .  24
   Appendix A.  An Example . . . . . . . . . . . . . . . . . . . . .  25
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  30

1.  Introduction

   [I-D.ietf-teas-ietf-network-slices] defines IETF network slice
   services that provide connectivity coupled with network resources
   commitment between a number of endpoints over a shared network
   infrastructure and, for scalability concerns, defines network
   resource partition (NRP) to host one or a group of network slice
   services according to characteristics including SLOs and SLEs.
   [I-D.dong-teas-nrp-scalability] analyzes the scalability issues of
   network slice services in detail and suggests candidate technologies
   of control and forwarding planes of the NRP.

   This document defines a YANG model of NRP that the IETF NSC (Network
   Slice controller) can use to manage NRP instances to realize the
   network slicing services.  According to the YANG model classification
   of [RFC8309], the NRP model is a network configuration model.

2.  Terminology

   The following terms are defined in [RFC6241] and are used in this
   specification:

   *  configuration data

   *  state data

   The following terms are defined in [RFC7950] and are used in this
   specification:



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   *  augment

   *  data model

   *  data node

   The terminology for describing YANG data models is found in
   [RFC7950].

2.1.  Tree Diagrams

   The tree diagram used in this document follows the notation defined
   in [RFC8340].

3.  NRP Modelling Consideration

   As specified in [I-D.ietf-teas-ietf-network-slices], an NRP is a
   subset of dedicated or shared nodes and links in a network, and
   includes associated control plane and forwarding plane technologies
   so that the traffic received from NRP edge nodes that is
   characterized to match the NRP traffic classification rule is
   constrained to the NRP exclusive topology and resource allocation.
   The NRP allows network operators to manage the resources of IETF
   network slices which are used to provide network slice service
   traffic with specific SLOs and SLEs.

   An NRP is a subset of resources allocated from a physical network or
   logical network.  Depending on the SLO and SLE requirements of the
   slicing service and also the available resources of the operator's
   network, there are several options of creating an NRP.  One option is
   that each physical link is allocated to only one specific NRP, and
   different NRPs do not share any physical link.  One more typical
   option is that multiple NRPs share the same physical links, and each
   NRP is built with virtual links with a certain subset of the
   bandwidth available on the physical links to provide network resource
   isolation.

   To constrain the traffic that matches NRP traffic classification to
   be forwarded based on the NRP topology and resources, an NRP also
   includes the control and forwarding plane functions.  As defined in
   [I-D.dong-teas-nrp-scalability], the draft discusses NRP control
   plane and data plane requirements in different provisioning
   scenarios, and describes that the NRP control plane is used to
   exchange network resource attributes and associated logical topology
   information between nodes of the NRP so that NRP-specific routing and
   forwarding tables could be generated.  For the NRP control plane,
   distributed control plane mechanism, such as Multi-topology, Flex-
   Algo or centralized SDN or hybrid combination could be defined.  To



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   help with forwarding entries, several data-plane encapsulation
   options are also discussed to carry NRP information in the NRP
   traffic packets.  The example NRP data plane identifier could be the
   IPv6 addresses or the MPLS forwarding labels or dedicated NRP data-
   plane identifiers.

   An example of NRP instances and a physical network is illustrated in
   Figure 1.  In the example, each NRP instance has a customized network
   topology comprised of a set of links and nodes in the physical
   network.  In control plane, each NRP could be associated with a
   multi-topology or a Flex-Algo.  And it also has its own forwarding
   plane resources and identifiers which provide NRP-specific packet
   forwarding.

               ++++   ++++   ++++
               +--+===+--+===+--+
               +--+===+--+===+--+
               ++++   +++\\  ++++
                ||     || \\  ||             Physical
                ||     ||  \\ ||             Network
        ++++   ++++   ++++  \\+++   ++++
        +  +===+--+===+--+===+--+===+  +
        +  +===+--+===+--+===+--+===+  +
        ++++   ++++   ++++   ++++   ++++
         PE1                         PE2
                         |
                        \|/

                o----o-----o
               /          /              NRP-1
        o-----o-----o----o----o


                o----o
               /    / \                  NRP-2
        o-----o----o---o------o

                                          ...

                     o----o
                    /    /               NPR-n
        o-----o----o----o-----o

           o   is a virtual node
           --- is a virtual link

                          Figure 1: An NRP Example




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   [I-D.ietf-teas-ietf-network-slices] also describes the management of
   the NRP.  After an NRP created, the NRP may need to be refined and
   modified as the network status and slice services change, and could
   be extended if necessary to meet the customers' demands.  In addition
   to configuration management, the NRP should also provide detailed
   monitoring information about underlying resources to further provide
   monitoring for the hosted slice services.

3.1.  NRP Model Usage example

   One major application of network slices is 5G services.  Figure 2
   shows the use of the NRP model to realize the IETF Network Slice for
   the 5G use case, based on the reference framework defined in
   [I-D.ietf-teas-ietf-network-slices].  The figure shows that the NSC
   uses the L3VPN network model [I-D.ietf-opsawg-l3sm-l3nm] to map to an
   IETF Network Slice service and uses the NRP model to map VPN traffic
   to underlying network resources, so that the SLO and SLE required by
   the IETF network slice service are ensured when the VPN service
   traverses the underlying network.

          +------------------------------------------+
          |                 Customer                 |
          |                                          |
          +------------------------------------------+
                               A
                               | Network slice service interface
                               V
          +------------------------------------------+
          |    IETF Network Slice Controller (NSC)   |
          +------------------------------------------+
                               A
                  L3NM model   | NSC SBI  NRP model
                               V          NRP as VPN underlay
          +------------------------------------------+
          |           Network Controller(s)          |
          +------------------------------------------+
                               A
                               |    Device model
                               V
       +------------------------------------------------+
                             Network

                    Figure 2: Reference Module Use Case

   In the process of realizing an IETF network slice service, the NSC
   can use a static NRP instance or dynamically create one as one or a
   group of VPNs underlay construct.  Compared with existing VPN
   underlying built with full mesh tunneling mechanisms, the NRP could



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   provide resource isolation, topology constraints, and simplified
   configuration.  Additionally, specific service flows of a VPN can be
   further optimized using SR policies defined in
   [I-D.dong-idr-sr-policy-vtn].

3.2.  NRP Modeling Design

   An NRP is modeled as network topology defined in [RFC8345] with
   augmentations.  A new network type "nrp" is defined.  A network
   topology data instance containing the nrp network type, indicates an
   NRP instance.

   As discussed in [I-D.dong-teas-nrp-scalability], an NRP could have
   multiple control plane implementation options.  For a better network
   scalability, an NRP does not require an independent Layer 3 topology,
   that is, multiple NRPs can share a same Layer 3 topology or TE
   topology.  Thus, an NRP can use a predefined basic TE topology by
   referring to the TE network instance or a predefined basic Layer3 TE
   topology by referring to the network instance with both TE and Layer3
   type enabled or other topology combination.  The Figure 3 shows the
   example references between this module and other YANG modules.






























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                                         +--------------------------+
                                         |  ietf-te-topology:       |
                                         |+------------------------+|
                                         || ietf-network-topology: ||
                                     +-->||   network-id (key)     ||
  +-------------------------------+  |   ||   network-types: {     ||
  |   ietf-nrp:                   |  |   ||     te-topology        ||
  | +---------------------------+ |  |   ||   }                    ||
  | | ietf-network-topology:    | |  |   ||   <other attributes>   ||
  | |   network-id (key)        | |  |   |+------------------------+|
  | |   network-types: {        | |  |   |    <TE attributes>       |
  | |     nrp:                  | |--+   +--------------------------+
  | |   }                       | |  |
  | |  <other attributes>       | |  |   +-----------------------------+
  | +---------------------------+ |  |   |  ietf-l3-te-topology:       |
  |    network-ref                |  |   |+---------------------------+|
  |                               |  |   || ietf-network-topology:    ||
  +-------------------------------+  |   ||   network-id (key)        ||
                                     |   ||   network-types: {        ||
                                     +-->||     l3-unicast-topology   ||
                                         ||     te-topology           ||
                                         ||   }                       ||
                                         ||   <other attributes>      ||
                                         |+---------------------------+|
                                         |    <L3 unicast attributes>  |
                                         |    <TE attributes>          |
                                         +-----------------------------+

                     Figure 3: Topology References

   But in some situations, an NRP may need its own Layer 3 topology or
   Traffic Engineering (TE) topology to support route forwarding or TE
   forwarding capability.  Inheriting the extensibility from [RFC8345],
   an NRP can have several types of networks simultaneously.  The Layer
   3 Topologies model defined in [RFC8346] can be used to enable an NRP
   unicast capable.  And the TE Topology model defined in [RFC8795] can
   be used to make an NRP TE capable.  The Figure 4 shows the
   relationship between this module and other YANG modules.













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                  +-----------------------+
                  |Network Topology Model |
                  |       RFC8345         |
                  +-----------------------+
                         |
           +-------------+-------------+-------------+
           |             |             |             |
           V             V             V             V
      ............ +----------+   ............  ............
      :   L3     : |  Network |   :    TE    :  :    L2    :
      :Topology  : | Resource |   : Topology :  : Topology :
      :  Model   : | Partition|   :   Model  :  :   Model  :
      :..........: |   Model  |   :..........:  :..........:
          |        +----------+
          |
          V
   .................
   : ospf-topology :
   :...............:

                      Figure 4: NRP Model Relationship

   The container "nrp" under 'network' of [RFC8345] defines global
   parameters for an NRP, which defines the specific control plane and
   data plane mechanisms of an NRP.  And also, the traffic steering
   policy of the NRP may include a dynamic color based policies or an
   ACL-based static ones.

   Each NRP instance consists of a set of nodes and a set of links.
   Each node and link have different attributes that represent the
   allocated resources or the operational status of the NRP.  An NRP
   could support several resource partition methods, which are defined
   by 'link-partition-type'' under an NRP link, which can further be
   supported by FlexE or independent queue techniques.

   There are multiple modes of NRP operations to be supported as
   follows:

   *  NRP instantiation: Depending on the slice services types and also
      network status, there can be two types of approaches.  One method
      is to create an NRP instance before the network controller
      processes the IETF network slice service request.  Another one is
      that the network controller may start creating an NRP instance
      while configuring the IETF network slice service request.







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   *  NRP modification: When the capacity of an existing NPR link is
      close to capacity, the bandwidth of the link could be increased.
      And when the NRP link or node resources are insufficient, new NRP
      links and nodes could be added.

   *  NRP Deletion: If the NSC determines that no slice service is using
      an NRP, the NSC can delete the NRP instance.

   *  NRP Monitoring: The NSC can use the NRP model to track and monitor
      NRP resource status and usage.

4.  Description of NRP YANG Module

   The description of the NRP data nodes are as follows:

   *  "nrp-id": Is an identifier that is used to uniquely identify an
      NRP instance within the network scope.

   *  NRP resources reservation: The nodes and links represent the
      network resource allocated for an NRP instance.  'bandwidth-
      reservation' specifies the bandwidth allocated to an NRP instance,
      or is overridden by the configuration of the NRP link.  'link-
      partition-type' specifies the resource partition types of the
      physical interfaces associated with an NRP link.

   *  NRP control plane: When an NRP shares an IGP topology or TE
      topology with other NRPs, "network-ref" or "te-topology-
      identifier" is used to refer to the existing IGP network instance
      or TE topology instance.  And an NRP can further use Multi-
      Topology Routing (MTR) or Flex-algo to refer to the IGP instance
      to generate its own NRP-specific forwarding tables.  Multi-
      Topology Routing (MTR) is defined in [RFC4915], [RFC5120], and
      [I-D.ietf-lsr-isis-sr-vtn-mt] or Flex-algo is defined in
      [I-D.ietf-lsr-flex-algo].

   *  NRP data plane: Defines the data plane mechanism and the NRP
      identifier of the network domain managed by the network
      controller.  The data plane mechanism could be based on MPLS or
      IPv6 forwarding.  The container "data plane" is used to specify
      the NRP data plane encapsulation types and values that are used to
      identify NRP-specific network resources.  The NRP data plane
      identifier is defined in [I-D.ietf-spring-sr-for-enhanced-vpn]
      and[I-D.dong-6man-enhanced-vpn-vtn-id].

   *  NRP steering policy: The leaf-list "color-id" is used for dynamic
      traffic steering based on SR policy of an NRP and The leaf-list
      "acl-ref" is used for common traffic steering.




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5.  NRP Yang Module Tree

   module: ietf-nrp
     augment /nw:networks/nw:network/nw:network-types:
       +--rw nrp!
     augment /nw:networks/nw:network:
       +--rw nrp
          +--rw nrp-id?                  uint32
          +--rw nrp-name?                string
          +--rw bandwidth-reservation
          |  +--rw (bandwidth-type)?
          |     +--:(bandwidth-value)
          |     |  +--rw bandwidth-value?     uint64
          |     +--:(bandwidth-percentage)
          |        +--rw bandwidth-percent?   rt-types:percentage
          +--rw control-plane
          |  +--rw topology-ref
          |     +--rw igp-topology-ref
          |     |  +--rw network-ref?
          |     |  |       -> /nw:networks/network/network-id
          |     |  +--rw multi-topology-id?   uint32
          |     |  +--rw flex-algo-id?        uint32
          |     +--rw te-topology-identifier
          |        +--rw provider-id?   te-global-id
          |        +--rw client-id?     te-global-id
          |        +--rw topology-id?   te-topology-id
          +--rw data-plane
          |  +--rw global-resource-identifier
          |  |  +--rw nrp-dataplane-ipv6-type
          |  |  |  +--rw nrp-dp-value?   inet:ipv6-address
          |  |  +--rw nrp-dataplane-mpls-type
          |  |     +--rw nrp-dp-value?   uint32
          |  +--rw nrp-aware-dp
          |     +--rw nrp-aware-srv6-type!
          |     +--rw nrp-aware-sr-mpls-type!
          +--rw steering-policy
             +--rw color-id*   uint32
             +--rw acl-ref*    -> /acl:acls/acl/name
     augment /nw:networks/nw:network/nw:node:
       +--rw nrp
          +--rw nrp-aware-srv6
          |  +--rw nrp-dp-value?   srv6-types:srv6-sid
          +--rw nrp-aware-sr-mpls
             +--rw nrp-dp-value?   rt-types:mpls-label
     augment /nw:networks/nw:network/nt:link:
       +--rw nrp
       |  +--rw link-partition-type?     identityref
       |  +--rw bandwidth-reservation



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       |  |  +--rw (bandwidth-type)?
       |  |     +--:(bandwidth-value)
       |  |     |  +--rw bandwidth-value?     uint64
       |  |     +--:(bandwidth-percentage)
       |  |        +--rw bandwidth-percent?   rt-types:percentage
       |  +--rw nrp-aware-srv6
       |  |  +--rw nrp-dp-value?   srv6-types:srv6-sid
       |  +--rw nrp-aware-sr-mpls
       |     +--rw nrp-dp-value?   rt-types:mpls-label
       +--ro statistics
          +--ro admin-status?                  te-types:te-admin-status
          +--ro oper-status?                   te-types:te-oper-status
          +--ro one-way-available-bandwidth?
          |       rt-types:bandwidth-ieee-float32
          +--ro one-way-utilized-bandwidth?
          |       rt-types:bandwidth-ieee-float32
          +--ro one-way-min-delay?             uint32
          +--ro one-way-max-delay?             uint32
          +--ro one-way-delay-variation?       uint32
          +--ro one-way-packet-loss?           decimal64

6.  NRP Yang Module

   <CODE BEGINS> file "ietf-nrp@2022-01-29.yang"

module ietf-nrp {
  yang-version 1.1;
  namespace "urn:ietf:params:xml:ns:yang:ietf-nrp";
  prefix nrp;

  import ietf-network {
    prefix nw;
    reference
      "RFC 8345: A YANG Data Model for Network Topologies";
  }
  import ietf-network-topology {
    prefix nt;
    reference
      "RFC 8345: A YANG Data Model for Network Topologies";
  }
  import ietf-routing-types {
    prefix rt-types;
    reference
      "RFC 8294: Common YANG Data Types for the Routing Area";
  }
  import ietf-te-types {
    prefix te-types;
    reference



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      "RFC 8776: Traffic Engineering Common YANG Types";
  }
  import ietf-te-packet-types {
    prefix te-packet-types;
    reference
      "RFC 8776: Traffic Engineering Common YANG Types";
  }
  import ietf-srv6-types {
    prefix srv6-types;
  }
  import ietf-inet-types {
    prefix inet;
    reference
      "RFC 6991: Common YANG Data Types";
  }
  import ietf-access-control-list {
    prefix acl;
    reference
      "RFC 8519: YANG Data Model for Network Access Control Lists
       (ACLs)";
  }

  organization
    "IETF TEAS Working Group";
  contact
    "
     WG Web: <http://tools.ietf.org/wg/teas/>
     WG List:<mailto:teas@ietf.org>

     Editor: Bo Wu <lana.wubo@huawei.com>
           : Dhruv Dhody <dhruv.ietf@gmail.com>";
  description
    "This YANG module defines a network data module for
     NRP(Network Resource Partition).

     Copyright (c) 2022 IETF Trust and the persons identified as
     authors of the code.  All rights reserved.

     Redistribution and use in source and binary forms, with or
     without modification, is permitted pursuant to, and subject to
     the license terms contained in, the Simplified BSD License set
     forth in Section 4.c of the IETF Trust's Legal Provisions
     Relating to IETF Documents
     (https://trustee.ietf.org/license-info).

     This version of this YANG module is part of RFC XXXX
     (https://www.rfc-editor.org/info/rfcXXXX); see the RFC itself
     for full legal notices.";



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  revision 2022-01-29 {
    description
      "This is the initial version of NRP YANG model.";
    reference
      "RFC XXX: A YANG Data Model for Network Resource Partition";
  }

  identity link-partition-type {
    description
      "Base identity for interface partition type.";
  }

  identity virtual-sub-interface-partition {
    base link-partition-type;
    description
      "Identity for virtual interface or sub-interface, e.g. FlexE.";
  }

  identity queue-partition {
    base link-partition-type;
    description
      "Identity for queue partition type.";
  }

  identity nrp-dataplane-type {
    description
      "Base identity for NRP data plane type.";
  }

  identity nrp-dataplane-ipv6 {
    base nrp-dataplane-type;
    description
      "Identity for NRP specific packet forwarding of IPv6.";
  }

  identity nrp-dataplane-mpls {
    base nrp-dataplane-type;
    description
      "Identity for NRP specific packet forwarding of MPLS.";
  }

  identity nrp-dataplane-sr-mpls {
    base nrp-dataplane-type;
    description
      "Identity for NRP specific packet forwarding of SR MPLS.";
  }

  identity nrp-dataplane-srv6 {



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    base nrp-dataplane-type;
    description
      "Identity for NRP specific packet forwarding of SRv6.";
  }

  /*
   * Groupings
   */

  grouping nrp-bandwidth-reservation {
    description
      "Grouping for NRP bandwidth reservation.";
    container bandwidth-reservation {
      description
        "Container for NRP bandwidth reservation.";
      choice bandwidth-type {
        description
          "Choice of bandwidth reservation type.";
        case bandwidth-value {
          leaf bandwidth-value {
            type uint64;
            units "bps";
            description
              "Bandwidth allocation for the NRP as absolute value.";
          }
        }
        case bandwidth-percentage {
          leaf bandwidth-percent {
            type rt-types:percentage;
            description
              "Bandwidth allocation for the NRP as a percentage
               of a link.";
          }
        }
      }
    }
  }

  grouping nrp-control-plane-attributes {
    description
      "Grouping for NRP control plane attributes.";
    container control-plane {
      description
        "The container of NRP control plane mechanisms.";
      container topology-ref {
        description
          "Container for topology reference.";
        container igp-topology-ref {



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          description
            "Container for IGP topology reference.";
          uses nw:network-ref;
          leaf multi-topology-id {
            type uint32;
            description
              "The MT-id of an NRP.";
          }
          leaf flex-algo-id {
            type uint32;
            description
              "The flex-algo-id of an NRP.";
          }
        }
        uses te-types:te-topology-identifier;
      }
    }
  }

  grouping nrp-data-plane-attributes {
    description
      "Grouping for NRP data plane attributes.";
    container data-plane {
      description
        "The data plane mechanisms of an NRP. The forwarding plane
         could be MPLS, IPv6, SRv6, or SR-MPLS.";
      container global-resource-identifier {
        description
          "The container of global NRP data-plane ID.";
        container nrp-dataplane-ipv6-type {
          description
            "The container of IPv6 based NRP data-plane identifier.";
          leaf nrp-dp-value {
            type inet:ipv6-address;
            description
              "Indicates the IPv6 NRP data-plane identifier.";
          }
        }
        container nrp-dataplane-mpls-type {
          description
            "The container of MPLS based NRP data-plane identifier.";
          leaf nrp-dp-value {
            type uint32;
            description
              "Indicates MPLS metadata values to identify MPLS NRP
               data plane identifier, e.g. Ancillary data.";
          }
        }



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      }
      container nrp-aware-dp {
        description
          "The container of SR based NRP data-plane identifier.";
        container nrp-aware-srv6-type {
          presence "Enables SRv6 data plane type.";
          description
            "The container of SRv6 based NRP data-plane identifier.";
        }
        container nrp-aware-sr-mpls-type {
          presence "Enables SR MPLS data plane type.";
          description
            "The container of SR MPLS based NRP data-plane identifier.";
        }
      }
    }
  }

  grouping nrp-traffic-steering-policy {
    description
      "The grouping of the NRP traffic steering policy.";
    container steering-policy {
      description
        "The container of a policy set
         matching an NRP traffic classifier.";
      leaf-list color-id {
        type uint32;
        description
          "A list of color ID for NRP traffic steering based on
           SR policy.";
      }
      leaf-list acl-ref {
        type leafref {
          path "/acl:acls/acl:acl/acl:name";
        }
        description
          "A list of ACL for NRP traffic classification.";
      }
    }
  }

  grouping nrp-aware-id {
    description
      "The grouping of NRP aware SR ID.";
    container nrp-aware-srv6 {
      description
        "The container of SRv6 based NRP data plane identifier.";
      leaf nrp-dp-value {



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        type srv6-types:srv6-sid;
        description
          "Indicates the SRv6 SID value as the NRP data plane
           identifier.";
      }
    }
    container nrp-aware-sr-mpls {
      description
        "The container of SR MPLS based NRP data plane identifier.";
      leaf nrp-dp-value {
        type rt-types:mpls-label;
        description
          "Indicates the SR MPLS ID value as the NRP data plane
           identifier.";
      }
    }
  }

  grouping nrp-topology-attributes {
    description
      "NRP global attributes.";
    container nrp {
      description
        "Containing NRP topology attributes.";
      leaf nrp-id {
        type uint32;
        description
          "NRP identifier.";
      }
      leaf nrp-name {
        type string;
        description
          "NRP Name.";
      }
      uses nrp-bandwidth-reservation;
      uses nrp-control-plane-attributes;
      uses nrp-data-plane-attributes;
      uses nrp-traffic-steering-policy;
    }
    // nrp
  }

  // nrp-node-attributes

  grouping nrp-node-attributes {
    description
      "NRP node scope attributes.";
    container nrp {



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      description
        "Containing NRP attributes.";
      uses nrp-aware-id;
    }
  }

  // nrp-node-attributes

  grouping nrp-link-attributes {
    description
      "NRP link scope attributes.";
    container nrp {
      description
        "Containing NRP attributes.";
      leaf link-partition-type {
        type identityref {
          base link-partition-type;
        }
        description
          "Indicates the resource partition type of a link.";
      }
      uses nrp-bandwidth-reservation;
      uses nrp-aware-id;
    }
  }

  // nrp-statistics

  grouping statistics-per-nrp {
    description
      "Statistics attributes per NRP.";
  }

  // nrp-node-statistics

  grouping statistics-per-node {
    description
      "Statistics attributes per NRP node.";
  }

  // one-way-performance-metrics

  grouping one-way-performance-bandwidth {
    description
      "Grouping for one-way performance bandwidth.";
    leaf one-way-available-bandwidth {
      type rt-types:bandwidth-ieee-float32;
      units "bytes per second";



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      default "0x0p0";
      description
        "Available bandwidth that is defined to be NRP link
         bandwidth minus bandwidth utilization. For a
         bundled link, available bandwidth is defined to be the
         sum of the component link available bandwidths.";
    }
    leaf one-way-utilized-bandwidth {
      type rt-types:bandwidth-ieee-float32;
      units "bytes per second";
      default "0x0p0";
      description
        "Bandwidth utilization that represents the actual
         utilization of the link (i.e. as measured in the router).
         For a bundled link, bandwidth utilization is defined to
         be the sum of the component link bandwidth
         utilizations.";
    }
  }

  // nrp-link-statistics

  grouping nrp-statistics-per-link {
    description
      "Statistics attributes per NRP link.";
    container statistics {
      config false;
      description
        "Statistics for NRP link.";
      leaf admin-status {
        type te-types:te-admin-status;
        description
          "The administrative state of the link.";
      }
      leaf oper-status {
        type te-types:te-oper-status;
        description
          "The current operational state of the link.";
      }
      uses one-way-performance-bandwidth;
      uses te-packet-types:one-way-performance-metrics-packet;
    }
  }

  augment "/nw:networks/nw:network/nw:network-types" {
    description
      "Defines the NRP topology type.";
    container nrp {



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      presence "Indicates NRP topology";
      description
        "The presence identifies the NRP type.";
    }
  }

  augment "/nw:networks/nw:network" {
    when 'nw:network-types/nrp:nrp' {
      description
        "Augment only for NRP topology.";
    }
    description
      "Augment NRP configuration and state.";
    uses nrp-topology-attributes;
  }

  augment "/nw:networks/nw:network/nw:node" {
    when '../nw:network-types/nrp:nrp' {
      description
        "Augment only for NRP topology.";
    }
    description
      "Augment node configuration and state.";
    uses nrp-node-attributes;
  }

  augment "/nw:networks/nw:network/nt:link" {
    when '../nw:network-types/nrp:nrp' {
      description
        "Augment only for NRP topology.";
    }
    description
      "Augment link configuration and state.";
    uses nrp-link-attributes;
    uses nrp-statistics-per-link;
  }
}

   <CODE ENDS>

7.  Security Considerations

   The YANG module defined in this document is designed to be accessed
   via network management protocols such as NETCONF [RFC6241] or
   RESTCONF [RFC8040].  The lowest NETCONF layer is the secure transport
   layer, and the mandatory-to-implement secure transport is Secure
   Shell (SSH) [RFC6242].  The lowest RESTCONF layer is HTTPS, and the
   mandatory-to-implement secure transport is TLS [RFC8446].



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   The NETCONF access control model [RFC8341] provides the means to
   restrict access for particular NETCONF or RESTCONF users to a
   preconfigured subset of all available NETCONF or RESTCONF protocol
   operations and content.

   There are a number of data nodes defined in this YANG module that are
   writable/creatable/deletable (i.e., config true, which is the
   default).  These data nodes may be considered sensitive or vulnerable
   in some network environments.  Write operations (e.g., edit-config)
   to these data nodes without proper protection can have a negative
   effect on network operations.

   nrp-link: A malicious client could attempt to remove a link from a
   topology, add a new link.  In each case, the structure of the
   topology would be sabotaged, and this scenario could, for example,
   result in an NRP topology that is less than optimal.

   The entries in the nodes above include the whole network
   configurations corresponding with the NRP, and indirectly create or
   modify the PE or P device configurations.  Unexpected changes to
   these entries could lead to service disruption and/or network
   misbehavior.

8.  IANA Considerations

   This document registers a URI in the IETF XML registry [RFC3688].
   Following the format in [RFC3688], the following registration is
   requested to be made:

      URI: urn:ietf:params:xml:ns:yang:ietf-nrp
      Registrant Contact: The IESG.
      XML: N/A, the requested URI is an XML namespace.

   This document requests to register a YANG module in the YANG Module
   Names registry [RFC7950].

              Name: ietf-nrp
              Namespace: urn:ietf:params:xml:ns:yang:ietf-nrp
              Prefix: nrp
              Reference: RFC XXXX

9.  Contributor









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      Zhenbin Li
      Huawei

      Email: lizhenbin@huawei.com


      Jie Dong
      Huawei

      Email: jie.dong@huawei.com

10.  References

10.1.  Normative References

   [I-D.dong-6man-enhanced-vpn-vtn-id]
              Dong, J., Li, Z., Xie, C., Ma, C., and G. Mishra,
              "Carrying Virtual Transport Network (VTN) Identifier in
              IPv6 Extension Header", Work in Progress, Internet-Draft,
              draft-dong-6man-enhanced-vpn-vtn-id-06, 24 October 2021,
              <https://www.ietf.org/archive/id/draft-dong-6man-enhanced-
              vpn-vtn-id-06.txt>.

   [I-D.dong-idr-sr-policy-vtn]
              Dong, J., Hu, Z., and R. Pang, "BGP SR Policy Extensions
              for Virtual Transport Network", Work in Progress,
              Internet-Draft, draft-dong-idr-sr-policy-vtn-01, 11 July
              2021, <https://www.ietf.org/archive/id/draft-dong-idr-sr-
              policy-vtn-01.txt>.

   [I-D.ietf-lsr-flex-algo]
              Psenak, P., Hegde, S., Filsfils, C., Talaulikar, K., and
              A. Gulko, "IGP Flexible Algorithm", Work in Progress,
              Internet-Draft, draft-ietf-lsr-flex-algo-18, 25 October
              2021, <https://www.ietf.org/archive/id/draft-ietf-lsr-
              flex-algo-18.txt>.

   [I-D.ietf-lsr-isis-sr-vtn-mt]
              Xie, C., Ma, C., Dong, J., and Z. Li, "Using IS-IS Multi-
              Topology (MT) for Segment Routing based Virtual Transport
              Network", Work in Progress, Internet-Draft, draft-ietf-
              lsr-isis-sr-vtn-mt-02, 13 January 2022,
              <https://www.ietf.org/archive/id/draft-ietf-lsr-isis-sr-
              vtn-mt-02.txt>.

   [I-D.ietf-spring-sr-for-enhanced-vpn]
              Dong, J., Bryant, S., Miyasaka, T., Zhu, Y., Qin, F., Li,
              Z., and F. Clad, "Segment Routing based Virtual Transport



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              Network (VTN) for Enhanced VPN", Work in Progress,
              Internet-Draft, draft-ietf-spring-sr-for-enhanced-vpn-01,
              12 July 2021, <https://www.ietf.org/archive/id/draft-ietf-
              spring-sr-for-enhanced-vpn-01.txt>.

   [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
              DOI 10.17487/RFC3688, January 2004,
              <https://www.rfc-editor.org/info/rfc3688>.

   [RFC4915]  Psenak, P., Mirtorabi, S., Roy, A., Nguyen, L., and P.
              Pillay-Esnault, "Multi-Topology (MT) Routing in OSPF",
              RFC 4915, DOI 10.17487/RFC4915, June 2007,
              <https://www.rfc-editor.org/info/rfc4915>.

   [RFC5120]  Przygienda, T., Shen, N., and N. Sheth, "M-ISIS: Multi
              Topology (MT) Routing in Intermediate System to
              Intermediate Systems (IS-ISs)", RFC 5120,
              DOI 10.17487/RFC5120, February 2008,
              <https://www.rfc-editor.org/info/rfc5120>.

   [RFC6241]  Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
              and A. Bierman, Ed., "Network Configuration Protocol
              (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
              <https://www.rfc-editor.org/info/rfc6241>.

   [RFC6242]  Wasserman, M., "Using the NETCONF Protocol over Secure
              Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
              <https://www.rfc-editor.org/info/rfc6242>.

   [RFC7950]  Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
              RFC 7950, DOI 10.17487/RFC7950, August 2016,
              <https://www.rfc-editor.org/info/rfc7950>.

   [RFC7951]  Lhotka, L., "JSON Encoding of Data Modeled with YANG",
              RFC 7951, DOI 10.17487/RFC7951, August 2016,
              <https://www.rfc-editor.org/info/rfc7951>.

   [RFC8040]  Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
              Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
              <https://www.rfc-editor.org/info/rfc8040>.

   [RFC8309]  Wu, Q., Liu, W., and A. Farrel, "Service Models
              Explained", RFC 8309, DOI 10.17487/RFC8309, January 2018,
              <https://www.rfc-editor.org/info/rfc8309>.

   [RFC8340]  Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
              BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
              <https://www.rfc-editor.org/info/rfc8340>.



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   [RFC8341]  Bierman, A. and M. Bjorklund, "Network Configuration
              Access Control Model", STD 91, RFC 8341,
              DOI 10.17487/RFC8341, March 2018,
              <https://www.rfc-editor.org/info/rfc8341>.

   [RFC8345]  Clemm, A., Medved, J., Varga, R., Bahadur, N.,
              Ananthakrishnan, H., and X. Liu, "A YANG Data Model for
              Network Topologies", RFC 8345, DOI 10.17487/RFC8345, March
              2018, <https://www.rfc-editor.org/info/rfc8345>.

   [RFC8346]  Clemm, A., Medved, J., Varga, R., Liu, X.,
              Ananthakrishnan, H., and N. Bahadur, "A YANG Data Model
              for Layer 3 Topologies", RFC 8346, DOI 10.17487/RFC8346,
              March 2018, <https://www.rfc-editor.org/info/rfc8346>.

   [RFC8446]  Rescorla, E., "The Transport Layer Security (TLS) Protocol
              Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
              <https://www.rfc-editor.org/info/rfc8446>.

   [RFC8795]  Liu, X., Bryskin, I., Beeram, V., Saad, T., Shah, H., and
              O. Gonzalez de Dios, "YANG Data Model for Traffic
              Engineering (TE) Topologies", RFC 8795,
              DOI 10.17487/RFC8795, August 2020,
              <https://www.rfc-editor.org/info/rfc8795>.

10.2.  Informative References

   [I-D.dong-teas-nrp-scalability]
              Dong, J., Li, Z., Gong, L., Yang, G., Guichard, J. N.,
              Mishra, G., and F. Qin, "Scalability Considerations for
              Network Resource Partition", Work in Progress, Internet-
              Draft, draft-dong-teas-nrp-scalability-00, 17 December
              2021, <https://www.ietf.org/archive/id/draft-dong-teas-
              nrp-scalability-00.txt>.

   [I-D.ietf-opsawg-l3sm-l3nm]
              Barguil, S., Dios, O. G. D., Boucadair, M., Munoz, L. A.,
              and A. Aguado, "A Layer 3 VPN Network YANG Model", Work in
              Progress, Internet-Draft, draft-ietf-opsawg-l3sm-l3nm-18,
              8 October 2021, <https://www.ietf.org/archive/id/draft-
              ietf-opsawg-l3sm-l3nm-18.txt>.










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   [I-D.ietf-teas-ietf-network-slices]
              Farrel, A., Gray, E., Drake, J., Rokui, R., Homma, S.,
              Makhijani, K., Contreras, L. M., and J. Tantsura,
              "Framework for IETF Network Slices", Work in Progress,
              Internet-Draft, draft-ietf-teas-ietf-network-slices-05, 25
              October 2021, <https://www.ietf.org/archive/id/draft-ietf-
              teas-ietf-network-slices-05.txt>.

Appendix A.  An Example

   This section contains an example of an instance data tree in JSON
   encoding [RFC7951].  The example instantiates ietf-nrp for the
   topology that is depicted in the following diagram.  There are three
   nodes, D1, D2, and D3.  D1 has three termination points, 1-0-1,
   1-2-1, and 1-3-1.  D2 has three termination points as well, 2-1-1,
   2-0-1, and 2-3-1.  D3 has two termination points, 3-1-1 and 3-2-1.
   In addition there are six links, two between each pair of nodes with
   one going in each direction.



                +------------+                   +------------+
                |     D1     |                   |     D2     |
               /-\          /-\                 /-\          /-\
               | | 1-0-1    | |---------------->| | 2-1-1    | |
               | |    1-2-1 | |<----------------| |    2-0-1 | |
               \-/  1-3-1   \-/                 \-/  2-3-1   \-/
                |   /----\   |                   |   /----\   |
                +---|    |---+                   +---|    |---+
                    \----/                           \----/
                     |  |                             |  |
                     |  |                             |  |
                     |  |                             |  |
                     |  |       +------------+        |  |
                     |  |       |     D3     |        |  |
                     |  |      /-\          /-\       |  |
                     |  +----->| | 3-1-1    | |-------+  |
                     +---------| |    3-2-1 | |<---------+
                               \-/          \-/
                                |            |
                                +------------+

                     Figure 5: An NRP Instance Example

   The corresponding NRP instance data tree is depicted below:






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   {
      "ietf-network:networks":{
         "network":[
            {
               "network-types":{
                  "ietf-nrp:nrp":{
                  }
               },
               "network-id":"nrp-example",
               "ietf-nrp:nrp":{
                  "nrp-id":"NRP1",
                  "bandwidth-reservation":{
                     "bandwidth-value":10000
                  },
                  "control-plane":{
                     "topology-ref":{
                        "igp-topology-ref":{
                           " network-ref":"L3-topology",
                           " flex-algo-id":129
                        }
                     }
                  },
                  "data-plane":{
                     "global-resource-identifier":{
                        "nrp-dataplane-ipv6-type":{
                           " nrp-dp-value:":100
                        }
                     }
                  },
                  "steering-policy":{
                     "color-id":100
                  }
               },
               "node":[
                  {
                     "node-id":"D1",
                     "termination-point":[
                        {
                           "tp-id":"1-0-1"
                        },
                        {
                           "tp-id":"1-2-1"
                        },
                        {
                           "tp-id":"1-3-1"
                        }
                     ]
                  },



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                  {
                     "node-id":"D2",
                     "termination-point":[
                        {
                           "tp-id":"2-0-1"
                        },
                        {
                           "tp-id":"2-1-1"
                        },
                        {
                           "tp-id":"2-3-1"
                        }
                     ]
                  },
                  {
                     "node-id":"D3",
                     "termination-point":[
                        {

                        },
                        {
                           "tp-id":"3-2-1"
                        }
                     ]
                  }
               ],
               "ietf-network-topology:link":[
                  {
                     "link-id":"D1,1-2-1,D2,2-1-1",
                     "source":{
                        "source-node":"D1",
                        "source-tp":"1-2-1"
                     },
                     "destination":{
                        "dest-node":"D2",
                        "dest-tp":"2-1-1"
                     },
                     "ietf-nrp:nrp":{
                        "link-partition-type":
                         "virtual-sub-interface-partition",
                        "bandwidth-reservation":{
                           "bandwidth-value":"10000"
                        },
                        "nrp-aware-srv6":{
                           " nrp-dp-value:":101
                        }
                     }
                  },



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                  {
                     "link-id":"D2,2-1-1,D1,1-2-1",
                     "source":{
                        "source-node":"D2",
                        "source-tp":"2-1-1"
                     },
                     "destination":{
                        "dest-node":"D1",
                        "dest-tp":"1-2-1"
                     },
                     "ietf-nrp:nrp":{
                        "link-partition-type":
                           "virtual-sub-interface-partition",
                        "bandwidth-reservation":{
                           "bandwidth-value":"10000"
                        },
                        "nrp-aware-srv6":{
                           " nrp-dp-value:":101
                        }
                     }
                  },
                  {
                     "link-id":"D1,1-3-1,D3,3-1-1",
                     "source":{
                        "source-node":"D1",
                        "source-tp":"1-3-1"
                     },
                     "destination":{
                        "dest-node":"D3",
                        "dest-tp":"3-1-1"
                     },
                     "ietf-nrp:nrp":{
                        "link-partition-type":
                          "virtual-sub-interface-partition",
                        "bandwidth-reservation":{
                           "bandwidth-value":"10000"
                        },
                        "nrp-aware-srv6":{
                           " nrp-dp-value:":101
                        }
                     }
                  },
                  {
                     "link-id":"D3,3-1-1,D1,1-3-1",
                     "source":{
                        "source-node":"D3",
                        "source-tp":"3-1-1"
                     },



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                     "destination":{
                        "dest-node":"D1",
                        "dest-tp":"1-3-1"
                     },
                     "ietf-nrp:nrp":{
                        "link-partition-type":
                      "virtual-sub-interface-partition",
                        "bandwidth-reservation":{
                           "bandwidth-value":"10000"
                        },
                        "nrp-aware-srv6":{
                           " nrp-dp-value:":101
                        }
                     }
                  },
                  {
                     "link-id":"D2,2-3-1,D3,3-2-1",
                     "source":{
                        "source-node":"D2",
                        "source-tp":"2-3-1"
                     },
                     "destination":{
                        "dest-node":"D3",
                        "dest-tp":"3-2-1"
                     },
                     "ietf-nrp:nrp":{
                        "link-partition-type":
                         "virtual-sub-interface-partition",
                        "bandwidth-reservation":{
                           "bandwidth-value":"10000"
                        },
                        "nrp-aware-srv6":{
                           " nrp-dp-value:":101
                        }
                     }
                  },
                  {
                     "link-id":"D3,3-2-1,D2,2-3-1",
                     "source":{
                        "source-node":"D3",
                        "source-tp":"3-2-1"
                     },
                     "destination":{
                        "dest-node":"D2",
                        "dest-tp":"2-3-1"
                     },
                     "ietf-nrp:nrp":{
                        "link-partition-type":



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                         "virtual-sub-interface-partition",
                        "bandwidth-reservation":{
                           "bandwidth-value":"10000"
                        },
                        "nrp-aware-srv6":{
                           " nrp-dp-value:":101
                        }
                     }
                  }
               ]
            }
         ]
      }
   }

                        Figure 6: Instance data tree

Authors' Addresses

   Bo Wu
   Huawei Technologies
   101 Software Avenue, Yuhua District
   Nanjing
   Jiangsu, 210012
   China

   Email: lana.wubo@huawei.com


   Dhruv Dhody
   Huawei Technologies
   Divyashree Techno Park
   Bangalore 560066
   Karnataka
   India

   Email: dhruv.ietf@gmail.com


   Ying Cheng
   China Unicom
   Beijing
   China

   Email: chengying10@chinaunicom.cn






Wu, et al.                Expires 3 August 2022                [Page 30]