Internet-Draft NRP YANG April 2023
Wu, et al. Expires 9 October 2023 [Page]
Workgroup:
Network Working Group
Internet-Draft:
draft-wdbsp-teas-nrp-yang-00
Published:
Intended Status:
Standards Track
Expires:
Authors:
B. Wu
Huawei Technologies
D. Dhody
Huawei Technologies
V.P. Beeram
Juniper Networks
T. Saad
Cisco Systems
S. Peng
ZTE Corporation

A YANG Data Model for Network Resource Partitions (NRPs)

Abstract

This document defines a YANG data model for Network Resource Partitions (NRPs). The model can be used, in particular, for the realization of the 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 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."

This Internet-Draft will expire on 9 October 2023.

Table of Contents

1. Introduction

[I-D.ietf-teas-ietf-network-slices] defines a framework for IETF Network Slice Services, which provide connectivity coupled with network resources commitment between a number of Service Demarcation Points (SDPs) over a shared network infrastructure. The IETF Network Slice service is expressed in terms of one or more connectivity constructs, which can be of a connection type (point-to-point (P2P), point-to-multipoint (P2MP), or any-to-any (A2A)) and any combination of these types.

This draft defines a YANG module of NRPs for mapping one or more connection constructs of one or more IETF network slices, for ensuring SLO and SLE and network scalability. An IETF Network Slice Controller (NSC) can use it to manage NRP instances in order to implement Network Slice Services.

An NRP Policy [I-D.ietf-teas-ns-ip-mpls] is a policy construct that enables instantiation of mechanisms in support of service specific control and data plane behaviors on select topological elements associated with the NRP.Section 3.1 describes the detailed definition of NRP policy in NRP instantiation.

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:

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

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

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

3. NRP Data Model

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

3.1. NRP Instantiation

An NRP policy specifies the rules for determining the topology associated with the NRP and dictates how an NRP can be realized in IP/MPLS networks using one of three partition modes. The NRP policy dictates if the partitioning of the shared network resources can be achieved in (a) just the data plane or in (b) just the control plane or in (c) both the control and data planes.

The NRP policy modes (a) and (c) require the forwarding engine on each NRP capable node to identify the traffic belonging to a specific NRP and to apply the corresponding Per-Hop Behavior (PHB) or forwarding mechanism that determines the forwarding treatment of the packets belonging to the NRP. When catering to IETF Network Slices, this NRP identification is referred to as the NRP selector and may comprises of traffic streams from one or more connectivity constructs (belonging to one or more IETF network slices) mapped to a specific NRP. The NRP policy modes (b) and (c) require the distributed/centralized resource reservation management.

'nrp-policy' is defined to enable NRP Stateful Traffic Engineering (NRP-TE) [I-D.ietf-teas-ns-ip-mpls] and/or NRP IGP forwarding in IP/MPLS networks.

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

The high-level model structure defined by this document is as shown below:

module: ietf-nrp
  augment /nw:networks:
    +--rw nrp-policies
       +--rw nrp-policy* [name]
          +--rw name                    string
          +--rw nrp-id?                 uint32
          +--rw mode?                   identityref
          +--rw resource-reservation
          |     ...
          +--rw selector
          |     ...
          +--rw phb-profile?            string
          +--rw topology
                ...

The 'networks' container from the 'ietf-network' module [RFC8345] provides a placeholder for an inventory of nodes in the network. This container is augmented to carry a set of NRP policies.

The 'nrp-policies' container carries a list of NRP policies. Each 'nrp-policy' entry is identified by a name and holds the set of attributes needed to instantiate the NRP. Each entry also carries an 'nrp-id' leaf which uniquely identifies the NRP created by the enforcement of this policy. The

The description of the 'nrp-policies' data nodes are as follows, and the other key elements of each nrp-policy entry are discussed in the following sub-sections.

  • 'nrp-id': Is an identifier that is used to uniquely identify an NRP instance within the NSC network scope.
  • 'mode': Refers to control plane resource partition, data plane resource partition, or a combination of both types.

3.1.1. Resource Reservation

The 'resource-reservation' container specifies the bandwidth resource allocated to an NRP instance, or can be overridden by the configuration of the link specific 'resource-reservation' nodes of 'nrp-topology'.

+--rw resource-reservation
  +--rw (max-bw-type)?
     +--:(bw-value)
     |  +--rw maximum-bandwidth?           uint64
     +--:(bw-percentage)
        +--rw maximum-bandwidth-percent?   rt-types:percentage

3.1.2. NRP Selector

NRP selector defines the data plane encapsulation types and values that are used to identify NRP-specific network resources. The data plane mechanism could be based on IP, MPLS, or SRv6 forwarding.

+--rw selector
   +--rw ipv4
   |  +--rw destination-prefix*   inet:ipv4-prefix
   +--rw ipv6
   |  +--rw (selector-type)?
   |     +--:(dedicated)
   |     |  +--rw ipv6-hbh-eh?          uint32
   |     +--:(srv6-sid-derived)
   |     |  +--rw srv6-sid*             inet:ipv6-prefix
   |     +--:(ipv6-destination-derived)
   |        +--rw destination-prefix*   inet:ipv6-prefix
   +--rw mpls
   |  +--rw (selector-type)?
   |     +--:(dedicated)
   |     |  +--rw label?                   rt-types:mpls-label
   |     |  +--rw label-position?          identityref
   |     |  +--rw label-position-offset?   uint8
   |     +--:(derived)
   |        +--rw forwarding-label?        empty
   +--rw acl-ref*   nrp-acl-ref

3.1.3. NRP Topology

'nrp-topology' defines a dedicated NRP topology.

When an NRP support IGP forwarding, the topology of NRP must be congruent with an IGP instance.The topology used for IGP route computation and forwarding can be derived using Multi-Topology Routing (MTR) or Flex-algo. 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].

The 'selection' container consists of a list of select subset of links of an underlay topology or a pre-built topology.

The 'filter' container consists of a list of filters where each entry references a topology filter [I-D.bestbar-teas-yang-topology-filter]. The topological elements that satisfy the membership criteria can optionally override the default resource-reservation and nrp-selector specific leafs.

+--rw topology
   +--rw igp-congruent!
   |  +--rw multi-topology-id?   uint32
   |  +--rw algo-id?             uint32
   |  +--rw sharing?             boolean
   +--rw (topology-type)?
      +--:(selection)
      |  +--rw select
      |     +--rw topology-group* [group-id]
      |        +--rw group-id                string
      |        +--rw base-topology-ref
      |        |     ...
      |        +--rw links* [link-ref]
      |        |     ...
      |        +--rw resource-reservation
      |        |     ...
      |        +--rw link-partition-type?
      |        |       identityref
      |        +--rw phb-profile?            string
      +--:(filter)
         +--rw filters
            +--rw filter* [filter-ref]
               +--rw filter-ref
               |       nrp-topo-filter-ref
               +--rw resource-reservation
               |     ...
               +--rw selector
               |     ...
               +--rw phb-profile?            string

3.2. NRP monitoring

The NRP model can be used to track and monitor NRP operational status and resource usage.

  augment /nw:networks/nw:network/nw:network-types:
    +--rw nrp!
  augment /nw:networks/nw:network/nw:node:
    +--ro nrp
       +--ro nrp-aware-dp-id
             ...
  augment /nw:networks/nw:network/nt:link:
    +--ro nrp
       +--ro link-partition-type?   identityref
       +--ro bandwidth-value?       uint64
       +--ro nrp-aware-dp-id
       |     ...
       +--ro statistics
             ...
  augment /nw:networks/nw:network/nw:node:
    +--ro nrps* [nrp-id]
       +--ro nrp-id    uint32
       +--ro nrp
             ...
  augment /nw:networks/nw:network/nt:link:
    +--ro nrps* [nrp-id]
       +--ro nrp-id                 uint32
       +--ro link-partition-type?   identityref
       +--ro bandwidth-value?       uint64
       +--ro nrp-aware-dp-id
             ...

3.3. NRP Device Model Description

This provides a placeholder for future definition of the NRP device model.

4. NRP Yang Module

The 'ietf-nrp' module uses types defined in [RFC8345].

<CODE BEGINS> file "ietf-nrp@2023-04-07.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
      "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)";
  }
  import ietf-topology-filter {
    prefix topo-filt;
    reference
      "draft-bestbar-teas-yang-topology-filter: YANG Data Model
       for Topology Filter";
  }

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

     Editor:   Bo Wu
            <mailto:lana.wubo@huawei.com>

     Editor:   Dhruv Dhody
            <mailto:dhruv.ietf@gmail.com>

     Editor:   Vishnu Pavan Beeram
               <mailto:vbeeram@juniper.net>

     Editor:   Tarek Saad
               <mailto:tsaad.net@gmail.com>

     Editor:   Shaofu Peng
               <mailto:peng.shaofu@zte.com.cn>";
  description
    "This YANG module defines a network data module for
     NRP(Network Resource Partition).

     Copyright (c) 2023 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 Revised 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.";

  revision 2023-04-07 {
    description
      "This is the initial version of NRP YANG model.";
    reference
      "RFC XXX: A YANG Data Model for Network Resource Partition";
  }

  /*
   * I D E N T I T I E S
   */

  identity nrp-partition-mode {
    description
      "Base identity for nrp partition type.";
  }

  identity nrp-control-plane-partition {
    base nrp-partition-mode;
    description
      "Identity for control plane partition.";
  }

  identity nrp-data-plane-partition {
    base nrp-partition-mode;
    description
      "Identity for data plane partition.";
  }

  identity nrp-hybrid-plane-partition {
    base nrp-partition-mode;
    description
      "Identity for both planes partition.";
  }

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

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

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

  /*
   * Identity:
   * MPLS Selector Label Position.
   */

  identity selector-mpls-label-position {
    description
      "Base identity for the position of the MPLS selector label.";
  }

  identity selector-mpls-label-position-top {
    base selector-mpls-label-position;
    description
      "MPLS selector label is at the top of the label stack.";
  }

  identity selector-mpls-label-position-bottom {
    base selector-mpls-label-position;
    description
      "MPLS selector label is either at the bottom or at a specific
       offset from the bottom of the label stack.";
  }

  identity selector-mpls-label-position-indicator {
    base selector-mpls-label-position;
    description
      "MPLS selector is preceded by a special purpose
       indicator label in the label stack.";
  }

  /*
   * T Y P E D E F S
   */

  typedef nrp-acl-ref {
    type leafref {
      path "/acl:acls/acl:acl/acl:name";
    }
    description
      "This type is used to reference an ACL.";
  }

  typedef nrp-topo-filter-ref {
    type leafref {
      path "/nw:networks/topo-filt:topology-filters/"
         + "topo-filt:topology-filter/topo-filt:name";
    }
    description
      "This type is used to reference a Topology Filter.";
  }

  /*
   * Grouping - NRP Resource Reservation
   */

  grouping nrp-resource-reservation {
    description
      "Grouping for NRP resource reservation.";
    container resource-reservation {
      description
        "Container for NRP resource reservation.";
      choice max-bw-type {
        description
          "Choice of maximum bandwidth specification.";
        case bw-value {
          leaf maximum-bandwidth {
            type uint64;
            description
              "The maximum bandwidth allocated to an NRP
               - specified as absolute value.";
          }
        }
        case bw-percentage {
          leaf maximum-bandwidth-percent {
            type rt-types:percentage;
            description
              "The maximum bandwidth allocated to an NRP
               - specified as percentage of link
               capacity.";
          }
        }
      }
    }
  }

  /*
   * G R O U P I N G S
   */
  /*
   * Grouping - MPLS selector label location specific fields
   */

  grouping nrp-selector-mpls-label-location {
    description
      "Grouping for MPLS FAS label location specific fields.";
    leaf label-position {
      type identityref {
        base selector-mpls-label-position;
      }
      description
        "MPLS selector label position.";
    }
    leaf label-position-offset {
      when "derived-from-or-self(../label-position,"
         + "'nrp:selector-mpls-label-position-bottom')" {
        description
          "MPLS label position offset is relevant only when the
           label-position is set to 'bottom'.";
      }
      type uint8;
      description
        "MPLS label position offset.";
    }
  }

  /*
   * Grouping - NRP Selector Configuration
   */

  grouping nrp-selector-config {
    description
      "Grouping for NRP selector configuration.";
    container selector {
      description
        "Container for NRP selector.";
      container ipv4 {
        description
          "Container for IPv4 NRP selector.";
        leaf-list destination-prefix {
          type inet:ipv4-prefix;
          description
            "Any prefix from the specified set of IPv4
             destination prefixes can be the selector.";
        }
      }
      container ipv6 {
        description
          "Container for IPv6 NRP selector.";
        choice selector-type {
          description
            "Choices for IPv6 selector type.";
          case dedicated {
            leaf ipv6-hbh-eh {
              type uint32;
              description
                "The selector value carried in Hop-by-Hop
                 Option of IPv6 extension header.";
            }
          }
          case srv6-sid-derived {
            leaf-list srv6-sid {
              type inet:ipv6-prefix;
              description
                "Any SID from the specified set of SRv6
                 SID can be the selector.";
            }
          }
          case ipv6-destination-derived {
            leaf-list destination-prefix {
              type inet:ipv6-prefix;
              description
                "Any prefix from the specified set of IPv6
                 destination prefixes can be the selector.";
            }
          }
        }
      }
      container mpls {
        description
          "Container for MPLS NRP selector.";
        choice selector-type {
          description
            "Choices for MPLS label specification.";
          case dedicated {
            leaf label {
              type rt-types:mpls-label;
              description
                "MPLS selector Label is explicitly
                 specified.";
            }
            uses nrp-selector-mpls-label-location;
          }
          case derived {
            leaf forwarding-label {
              type empty;
              description
                "MPLS selector Label is derived from
                 forwarding label.";
            }
          }
        }
      }
      leaf-list acl-ref {
        type nrp-acl-ref;
        description
          "Selection is done based on the specified list of ACLs.";
      }
    }
  }

  /*
   * Grouping - NRP QoS PHB profile
   */

  grouping nrp-qos-phb-profile {
    description
      "Grouping for NRP QoS PHB profile.";
    leaf phb-profile {
      type string;
      description
        "PHB profile identifier.";
    }
  }

  /*
   * Grouping - NRP IGP congruent
   */

  grouping nrp-igp-congruent {
    description
      "Grouping for NRP IGP congruent attributes.";
    container igp-congruent {
      presence "indicates NRP IGP congruent";
      description
        "The presence of the container node indicates NRP IGP
         congruent.";
      leaf multi-topology-id {
        type uint32;
        description
          "Indicates the MT-id of the NRP IGP instance.";
      }
      leaf algo-id {
        type uint32;
        description
          "Indicates the algo-id of the NRP IGP instance.";
      }
      leaf sharing {
        type boolean;
        default "true";
        description
          "'true' if the the NRP IGP instance can be shared with
           other NRPs;
           'false' if the the NRP IGP instance is dedicated
           to this NRP.";
      }
    }
  }

  /*
   * Grouping - NRP Topology Filter
   */

  grouping nrp-topology-filter {
    description
      "Grouping for NRP filter topology.";
    container filters {
      description
        "Container for filters.";
      list filter {
        key "filter-ref";
        description
          "List of filters.";
        leaf filter-ref {
          type nrp-topo-filter-ref;
          description
            "Reference to a specific topology filter from the
             list of global topology filters.";
        }
        uses nrp-resource-reservation;
        uses nrp-selector-config;
        uses nrp-qos-phb-profile;
      }
    }
  }

  /*
   * Grouping - NRP Select Topology
   */

  grouping nrp-select-topology {
    description
      "NRP topology specified by selection.";
    container select {
      description
        "The container of NRP select topology.";
      list topology-group {
        key "group-id";
        description
          "List of groups for NRP topology elements (node or links)
           that share common attributes.";
        leaf group-id {
          type string;
          description
            "The NRP topology group identifier.";
        }
        container base-topology-ref {
          description
            "Container for the base topology reference.";
          uses nw:network-ref;
        }
        list links {
          key "link-ref";
          description
            "A list of links with common attributes";
          leaf link-ref {
            type leafref {
              path
                "/nw:networks/nw:network[nw:network-id=current()"
              + "/../../base-topology-ref/network-ref]"
              + "/nt:link/nt:link-id";
            }
            description
              "A reference to a link in the base topology.";
          }
        }
        uses nrp-resource-reservation;
        leaf link-partition-type {
          type identityref {
            base nrp-link-partition-type;
          }
          description
            "Indicates the resource reservation type of an NRP link.";
        }
        uses nrp-qos-phb-profile;
      }
    }
  }

  /*
   * Grouping - NRP Topology
   */

  grouping nrp-topology {
    description
      "Grouping for NRP topology.";
    container topology {
      description
        "Container for NRP topology.";
      uses nrp-igp-congruent;
      choice topology-type {
        description
          "Choice of NRP topology type.";
        case selection {
          uses nrp-select-topology;
        }
        case filter {
          uses nrp-topology-filter;
        }
      }
    }
  }

  /*
   * Grouping - NRP Policy
   */

  grouping nrp-pol {
    description
      "Grouping for NRP policies.";
    container nrp-policies {
      description
        "Container for nrp policies.";
      list nrp-policy {
        key "name";
        unique "nrp-id";
        description
          "List of NRP policies.";
        leaf name {
          type string;
          description
            "A string that uniquely identifies the NRP policy.";
        }
        leaf nrp-id {
          type uint32;
          description
            "A 32-bit ID that uniquely identifies the NRP
             created by the enforcement of this NRP policy.";
        }
        leaf mode {
          type identityref {
            base nrp-partition-mode;
          }
          default "nrp-hybrid-plane-partition";
          description
            "Indicates the resource partition mode of the NRP, such as
             control plane partition, data plane partition,
             or hybrid partition.";
        }
        uses nrp-resource-reservation;
        uses nrp-selector-config;
        uses nrp-qos-phb-profile;
        uses nrp-topology;
      }
    }
  }

  /*
   * Grouping - NRP Selector State
   */

  grouping nrp-selector-state {
    description
      "The grouping of NRP selector.";
    container selector {
      config false;
      description
        "The container of NRP selector.";
      leaf srv6 {
        type srv6-types:srv6-sid;
        description
          "Indicates the SRv6 SID value as the NRP selector.";
      }
      leaf sr-mpls {
        type rt-types:mpls-label;
        description
          "Indicates the SR MPLS ID value as the NRP selector.";
      }
    }
  }

  /*
   * Grouping - NRP node attributes
   */

  grouping nrp-node-attributes {
    description
      "NRP node scope attributes.";
    container nrp {
      config false;
      description
        "Containing NRP attributes.";
      uses nrp-selector-state;
    }
  }

  /*
   * Grouping - NRP Link Attributes
   */

  grouping nrp-link-attributes {
    description
      "NRP link scope attributes.";
    leaf link-partition-type {
      type identityref {
        base nrp-link-partition-type;
      }
      config false;
      description
        "Indicates the resource partition type of an NRP link.";
    }
    leaf bandwidth-value {
      type uint64;
      units "bps";
      config false;
      description
        "Bandwidth allocation for the NRP as absolute value.";
    }
    uses nrp-selector-state;
  }

  /*
   * Grouping - NRP Bandwidth Metrics
   */

  grouping nrp-bandwidth-metrics {
    description
      "Grouping for NRP bandwidth metrics.";
    leaf one-way-available-bandwidth {
      type rt-types:bandwidth-ieee-float32;
      units "bytes per second";
      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 nrp-bandwidth-metrics;
      uses te-packet-types:one-way-performance-metrics-packet;
    }
  }

  grouping nrp-topology-type {
    description
      "Identifies the topology type to be NRP";
    container nrp {
      presence "indicates NRP topology";
      description
        "The presence of the container node indicates NRP
         topology";
    }
  }

  /*
   * Augment - Network Resource Partition Policies.
   */

  augment "/nw:networks" {
    description
      "Augment networks with network resource partition
       policies.";
    uses nrp-pol;
  }

  /*
   * Augment - NRP type.
   */

  augment "/nw:networks/nw:network/nw:network-types" {
    description
      "Introduces new network type for NRP topology";
    uses nrp-topology-type;
  }

  /*
   * Augment - NRP node operational status.
   */

  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 - NRP link operational status.
   */

  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.";
    container nrp {
      config false;
      description
        "Containing NRP attributes.";
      uses nrp-link-attributes;
      uses nrp-statistics-per-link;
    }
  }

  /*
   * Augment - Native topology with node operational status.
   */

  augment "/nw:networks/nw:network/nw:node" {
    description
      "Augment node with NRP aware attributes.";
    list nrps {
      key "nrp-id";
      config false;
      description
        "List of NRPs.";
      leaf nrp-id {
        type uint32;
        description
          "NRP identifier";
      }
      uses nrp-node-attributes;
    }
  }

  /*
   * Augment - Native topology with link operational status.
   */

  augment "/nw:networks/nw:network/nt:link" {
    description
      "Augment link with NRP attributes.";
    list nrps {
      key "nrp-id";
      config false;
      description
        "List of NRPs.";
      leaf nrp-id {
        type uint32;
        description
          "NRP identifier";
      }
      uses nrp-link-attributes;
    }
  }
}

<CODE ENDS>

5. Security Considerations

The YANG model 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].

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 model 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.

6. 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
           Maintained by IANA: N
           Prefix: nrp
           Reference: RFC XXXX

7. Acknowledgments

The authors would like to thank Krzysztof Szarkowicz, Jie Dong, Qin Wu, Yao Zhao, Zhenbing Li, Ying Cheng, Liyan Gong, and many others for their helpful comments and suggestions.

8. Contributor

The following individuals, authors of [I-D.bestbar-teas-yang-nrp-policy] and [I-D.wd-teas-nrp-yang], contributed to this consolidated document:

   Xufeng Liu
   IBM Corporation
   Email: xufeng.liu.ietf@gmail.com

   Mohamed Boucadair
   Orange
   Email: mohamed.boucadair@orange.com

   Daniele Ceccarelli

   Bin Wen
   Comcast
   Email: Bin_Wen@cable.comcast.com

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

   Luis M. Contreras
   Telefonica
   Email: luismiguel.contrerasmurillo@telefonica.com

   Ying Cheng
   China Unicom
   Email: chengying10@chinaunicom.cn

   Liyan Gong
   China Mobile
   Email: gongliyan@chinamobile.com

9. References

9.1. Normative References

[RFC3688]
Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, , <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, , <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, , <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, , <https://www.rfc-editor.org/info/rfc6241>.
[RFC6242]
Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, , <https://www.rfc-editor.org/info/rfc6242>.
[RFC7950]
Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, , <https://www.rfc-editor.org/info/rfc7950>.
[RFC7951]
Lhotka, L., "JSON Encoding of Data Modeled with YANG", RFC 7951, DOI 10.17487/RFC7951, , <https://www.rfc-editor.org/info/rfc7951>.
[RFC8040]
Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, , <https://www.rfc-editor.org/info/rfc8040>.
[RFC8340]
Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, , <https://www.rfc-editor.org/info/rfc8340>.
[RFC8341]
Bierman, A. and M. Bjorklund, "Network Configuration Access Control Model", STD 91, RFC 8341, DOI 10.17487/RFC8341, , <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, , <https://www.rfc-editor.org/info/rfc8345>.
[RFC8446]
Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10.17487/RFC8446, , <https://www.rfc-editor.org/info/rfc8446>.

9.2. Informative References

[I-D.bestbar-teas-yang-nrp-policy]
Beeram, V. P., Saad, T., Wen, B., Ceccarelli, D., Peng, S., Chen, R., Contreras, L. M., and X. Liu, "YANG Data Model for Network Resource Partition Policy", Work in Progress, Internet-Draft, draft-bestbar-teas-yang-nrp-policy-03, , <https://datatracker.ietf.org/doc/html/draft-bestbar-teas-yang-nrp-policy-03>.
[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-26, , <https://datatracker.ietf.org/doc/html/draft-ietf-lsr-flex-algo-26>.
[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-04, , <https://datatracker.ietf.org/doc/html/draft-ietf-lsr-isis-sr-vtn-mt-04>.
[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 IETF Network Slices", Work in Progress, Internet-Draft, draft-ietf-teas-ietf-network-slices-19, , <https://datatracker.ietf.org/doc/html/draft-ietf-teas-ietf-network-slices-19>.
[I-D.ietf-teas-ns-ip-mpls]
Saad, T., Beeram, V. P., Dong, J., Wen, B., Ceccarelli, D., Halpern, J. M., Peng, S., Chen, R., Liu, X., Contreras, L. M., Rokui, R., and L. Jalil, "Realizing Network Slices in IP/MPLS Networks", Work in Progress, Internet-Draft, draft-ietf-teas-ns-ip-mpls-02, , <https://datatracker.ietf.org/doc/html/draft-ietf-teas-ns-ip-mpls-02>.
[I-D.wd-teas-nrp-yang]
Wu, B., Dhody, D., Boucadair, M., Cheng, Y., and L. Gong, "A YANG Data Model for Network Resource Partitions (NRPs)", Work in Progress, Internet-Draft, draft-wd-teas-nrp-yang-02, , <https://datatracker.ietf.org/doc/html/draft-wd-teas-nrp-yang-02>.
[RFC8309]
Wu, Q., Liu, W., and A. Farrel, "Service Models Explained", RFC 8309, DOI 10.17487/RFC8309, , <https://www.rfc-editor.org/info/rfc8309>.
[RFC9182]
Barguil, S., Gonzalez de Dios, O., Ed., Boucadair, M., Ed., Munoz, L., and A. Aguado, "A YANG Network Data Model for Layer 3 VPNs", RFC 9182, DOI 10.17487/RFC9182, , <https://www.rfc-editor.org/info/rfc9182>.
[RFC9291]
Boucadair, M., Ed., Gonzalez de Dios, O., Ed., Barguil, S., and L. Munoz, "A YANG Network Data Model for Layer 2 VPNs", RFC 9291, DOI 10.17487/RFC9291, , <https://www.rfc-editor.org/info/rfc9291>.

Appendix A. An Example

This section contains an example of an instance data tree in JSON encoding [RFC7951]. The example below instantiates an 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 1: An NRP Instance Example

An corresponding IGP congruent NRP instance data tree is depicted below:

{
  "ietf-network:networks": {
    "nrp-policies": {
      "nrp-policy": [
        {
          "name": "NRP1",
          "nrp-id": "foo:nrp-example1",
          "mode": "nrp-hybrid-plane-partition",
          "resource-reservation": {
            "bw-value": "10000"
          },
          "selector": {
            "ipv6": {
              " ipv6-hbh-eh:": "100"
            }
          },
          "topology": {
            "igp-congruent": {
              "multi-topology-id": "2"
            },
            "select": {
              "topology-group": [
                {
                  "group-id": "access-group",
                  "base-topology-ref": {
                    "network-ref": "native-topology"
                  },
                  "link": [
                    {
                      "link-ref": "D1,1-2-1,D2,2-1-1"
                    },
                    {
                      "link-ref": "D2,2-1-1,D1,1-2-1"
                    },
                    {
                      "link-ref": "D1,1-3-1,D3,3-1-1"
                    },
                    {
                      "link-ref": "D3,3-1-1,D1,1-3-1"
                    },
                    {
                      "link-ref": "D2,2-3-1,D3,3-2-1"
                    },
                    {
                      "link-ref": "D3,3-2-1,D2,2-3-1"
                    }
                  ],
                  "link-partition-type": "virtual-sub-interface-partition"
                }
              ]
            }
          }
        }
      ]
    }
  }
}
Figure 2: Instance data tree

In addition, an exampe of an NRP that supports the control plane partition mode is shown in the following figure.

{
  "ietf-network:networks": {
    "nrp-policies": {
      "nrp-policy": [
        {
          "name": "NRP2",
          "nrp-id": "foo:nrp-example2",
          "mode": "nrp-control-plane-partition",
          "resource-reservation": {
            "bw-value": "10000"
          },
          "topology": {
            "filters": {
              "filter": [
                {
                  "filter-ref": "te-topology-filter1"
                }
              ]
            }
          }
        }
      ]
    }
  }
}

Appendix B. NRP YANG Module Tree

module: ietf-nrp
  augment /nw:networks:
    +--rw nrp-policies
       +--rw nrp-policy* [name]
          +--rw name                    string
          +--rw nrp-id?                 uint32
          +--rw mode?                   identityref
          +--rw resource-reservation
          |  +--rw (max-bw-type)?
          |     +--:(bw-value)
          |     |  +--rw maximum-bandwidth?           uint64
          |     +--:(bw-percentage)
          |        +--rw maximum-bandwidth-percent?
          |                rt-types:percentage
          +--rw selector
          |  +--rw ipv4
          |  |  +--rw destination-prefix*   inet:ipv4-prefix
          |  +--rw ipv6
          |  |  +--rw (selector-type)?
          |  |     +--:(dedicated)
          |  |     |  +--rw ipv6-hbh-eh?          uint32
          |  |     +--:(srv6-sid-derived)
          |  |     |  +--rw srv6-sid*
          |  |     |          inet:ipv6-prefix
          |  |     +--:(ipv6-destination-derived)
          |  |        +--rw destination-prefix*
          |  |                inet:ipv6-prefix
          |  +--rw mpls
          |  |  +--rw (selector-type)?
          |  |     +--:(dedicated)
          |  |     |  +--rw label?
          |  |     |  |       rt-types:mpls-label
          |  |     |  +--rw label-position?          identityref
          |  |     |  +--rw label-position-offset?   uint8
          |  |     +--:(derived)
          |  |        +--rw forwarding-label?        empty
          |  +--rw acl-ref*   nrp-acl-ref
          +--rw phb-profile?            string
          +--rw topology
             +--rw igp-congruent!
             |  +--rw multi-topology-id?   uint32
             |  +--rw algo-id?             uint32
             |  +--rw sharing?             boolean
             +--rw (topology-type)?
                +--:(selection)
                |  +--rw select
                |     +--rw topology-group* [group-id]
                |        +--rw group-id                string
                |        +--rw base-topology-ref
                |        |  +--rw network-ref?   leafref
                |        +--rw links* [link-ref]
                |        |  +--rw link-ref    leafref
                |        +--rw resource-reservation
                |        |  +--rw (max-bw-type)?
                |        |     +--:(bw-value)
                |        |     |  +--rw maximum-bandwidth?
                |        |     |          uint64
                |        |     +--:(bw-percentage)
                |        |        +--rw maximum-bandwidth-percent?
                |        |                rt-types:percentage
                |        +--rw link-partition-type?
                |        |       identityref
                |        +--rw phb-profile?            string
                +--:(filter)
                   +--rw filters
                      +--rw filter* [filter-ref]
                         +--rw filter-ref
                         |       nrp-topo-filter-ref
                         +--rw resource-reservation
                         |  +--rw (max-bw-type)?
                         |     +--:(bw-value)
                         |     |  +--rw maximum-bandwidth?
                         |     |          uint64
                         |     +--:(bw-percentage)
                         |        +--rw maximum-bandwidth-percent?
                         |                rt-types:percentage
                         +--rw selector
                         |  +--rw ipv4
                         |  |  +--rw destination-prefix*
                         |  |          inet:ipv4-prefix
                         |  +--rw ipv6
                         |  |  +--rw (selector-type)?
                         |  |     +--:(dedicated)
                         |  |     |  +--rw ipv6-hbh-eh?
                         |  |     |          uint32
                         |  |     +--:(srv6-sid-derived)
                         |  |     |  +--rw srv6-sid*
                         |  |     |          inet:ipv6-prefix
                         |  |     +--:(ipv6-destination-derived)
                         |  |        +--rw destination-prefix*
                         |  |                inet:ipv6-prefix
                         |  +--rw mpls
                         |  |  +--rw (selector-type)?
                         |  |     +--:(dedicated)
                         |  |     |  +--rw label?
                         |  |     |  |       rt-types:mpls-label
                         |  |     |  +--rw label-position?
                         |  |     |  |       identityref
                         |  |     |  +--rw label-position-offset?
                         |  |     |          uint8
                         |  |     +--:(derived)
                         |  |        +--rw forwarding-label?
                         |  |                empty
                         |  +--rw acl-ref*   nrp-acl-ref
                         +--rw phb-profile?            string
  augment /nw:networks/nw:network/nw:network-types:
    +--rw nrp!
  augment /nw:networks/nw:network/nw:node:
    +--ro nrp
       +--ro selector
          +--ro srv6?      srv6-types:srv6-sid
          +--ro sr-mpls?   rt-types:mpls-label
  augment /nw:networks/nw:network/nt:link:
    +--ro nrp
       +--ro link-partition-type?   identityref
       +--ro bandwidth-value?       uint64
       +--ro selector
       |  +--ro srv6?      srv6-types:srv6-sid
       |  +--ro sr-mpls?   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
  augment /nw:networks/nw:network/nw:node:
    +--ro nrps* [nrp-id]
       +--ro nrp-id    uint32
       +--ro nrp
          +--ro selector
             +--ro srv6?      srv6-types:srv6-sid
             +--ro sr-mpls?   rt-types:mpls-label
  augment /nw:networks/nw:network/nt:link:
    +--ro nrps* [nrp-id]
       +--ro nrp-id                 uint32
       +--ro link-partition-type?   identityref
       +--ro bandwidth-value?       uint64
       +--ro selector
          +--ro srv6?      srv6-types:srv6-sid
          +--ro sr-mpls?   rt-types:mpls-label

Authors' Addresses

Bo Wu
Huawei Technologies
101 Software Avenue, Yuhua District
Nanjing
Jiangsu, 210012
China
Dhruv Dhody
Huawei Technologies
Divyashree Techno Park
Bangalore 560066
Karnataka
India
Vishnu Pavan Beeram
Juniper Networks
Tarek Saad
Cisco Systems
Shaofu Peng
ZTE Corporation