etsi-nfv-ns.yang

submodule etsi-nfv-ns {
  yang-version 1.1;
  belongs-to etsi-nfv-descriptors {
    prefix nfv;
  }

  include etsi-nfv-common;
  include etsi-nfv-vnf;
  include etsi-nfv-pnf;

  description
    "Models for NS according to ETSI GS NFV-IFA 014.";

  revision 2019-04-25 {
    description
      "Initial revision
       Common data structure to support NSD according to:
       ETSI GS NFV-IFA 014 Ed261v252";

    reference
      "ETSI GS NFV-IFA 014 Ed261v252";
  }

  grouping resource-handle {
    leaf vim-id {
      type string;
    }
    leaf resource-provider-id {
      type string;
    }
    leaf resource-id {
      type string;
    }
  }


  grouping nsd {
    leaf id {
      type string;
      description
        "Identifier of this NSD information element. It Globally
         uniquely identifies an instance of the NSD.";
      reference
        "GS NFV IFA014: Section 6.2.2.2 Network Service Descriptor
         information element";
    }

    leaf designer {
      type string;
      description
        "Identifies the designer of the NSD.";
      reference
        "GS NFV IFA014: Section 6.2.2.2 Network Service Descriptor
         information element";
    }

    leaf version {
      type string;
      description
        "Identifies the version of the NSD.";
      reference
        "GS NFV IFA014: Section 6.2.2.2 Network Service Descriptor
         information element";
    }

    leaf name {
      type string;
      description
        "Provides the human readable name of the NSD.";
      reference
        "GS NFV IFA014: Section 6.2.2.2 Network Service Descriptor
         information element";
    }

    leaf invariant-id {
      type string;
      description
        "Identifies an NSD in a version independent manner. This
         attribute is invariant across versions of the network
         service descriptor.";
      reference
        "GS NFV IFA014: Section 6.2.2.2 Network Service Descriptor
         information element";
    }

    leaf-list nested-nsd-id {
      must ". != ../id";
      type leafref {
        path "../../nsd/id";
      }
      description
        "References the NSD of a constituent nested NS.";
      reference
        "GS NFV IFA014: Section 6.2.2.2 Network Service Descriptor
         information element";
    }

    leaf-list vnfd-id {
      type leafref {
        path "../../vnfd/id";
      }
      description
        "References the VNFD of a constituent VNF.";
      reference
        "GS NFV IFA014: Section 6.2.2.2 Network Service Descriptor
         information element";
    }

    leaf-list pnfd-id {
      type leafref {
        path "../../pnfd/id";
      }
      description
        "References the PNFD of a constituent PNF.";
      reference
        "GS NFV IFA014: Section 6.2.2.2 Network Service Descriptor
         information element";
    }

    list sapd {
      key "id";
      description
        "Provides the descriptor of a service access point of the
         network service.";
      reference
        "GS NFV IFA014: Section 6.2.2.2 Network Service Descriptor
         information element";

      leaf id {
        type string;
        description
          "Identifier of this Cpd information element.";
        reference
          "GS NFV IFA014: Section 6.6.3.1 Cpd information element";
      }

      leaf address-assignment {
        type boolean;
        description
          "Specify whether the SAP address assignment is under the
           responsibility of management and orchestration functions
           or not. If it is set to True, management and
           orchestration functions are responsible for assigning
           addresses to the access points instantiated from this
           SAPD.";
        reference
          "GS NFV IFA014: Section 6.2.3.2 Sapd information element";
      }

      choice cpd-or-virtual-link {
        leaf virtual-link-desc {
          type leafref {
            path "../../virtual-link-desc/id";
          }
          description
            "References the descriptor of the NS VL instance to
             which the SAP instantiated from this SAPD connects to.";
          reference
            "GS NFV IFA014: Section 6.2.3.2 Sapd information element";
        }

        choice associated-cpd-id {
          container vnf {
            leaf vnfd-id {
              mandatory true;
              type leafref {
                path "../../../../vnfd/id";
              }
              must "boolean(../../../vnfd-id[.=current()])";
            }

            leaf ext-cpd-id {
              mandatory true;
              type leafref {
                path "deref(../vnfd-id)/../ext-cpd/id";
              }
            }
          }

          container pnf {
            leaf pnfd-id {
              mandatory true;
              type leafref {
                path "../../../../pnfd/id";
              }
              must "boolean(../pnfd-id[.=current()])";
            }

            leaf ext-cpd-id {
              mandatory true;
              type leafref {
                path "deref(../pnfd-id)/../ext-cpd/id";
              }
            }
          }
          container ns {
            leaf nsd-id {
              mandatory true;
              type leafref {
                path "../../../../nsd/id";
              }
              must "boolean(../nsd-id[.=current()])";
            }

            leaf ext-cpd-id {
              mandatory true;
              type leafref {
                path "deref(../nsd-id)/../sapd/id";
              }
            }
          }
        }
      }
    }

    list virtual-link-desc {
      key "id";
      description
        "Provides the constituent VLDs.";
      reference
        "GS NFV IFA014: Section 6.2.2.2 Network Service Descriptor
         information element";
      leaf id {
        type string;
        description
          "Identifier of the NsVirtualLinkDesc information element.
           It uniquely identifies a VLD.";
        reference
          "GS NFV IFA014: Section 6.5.2.2 NsVirtualLinkDesc
           information element";
      }

      uses connectivity-type;

      list df {
        key "id";

        description
          "The VirtualLinkDf information element specifies
           properties for instantiating a VL according to a
           specific flavour.";
        reference
          "GS NFV IFA014: Section 6.5.2.2 NsVirtualLinkDesc
           information element";

        leaf id {
          type string;
          description
            "Identifies this VirtualLinkDf information element
             within a VLD.";
          reference
            "GS NFV IFA014: Section 6.5.4.2 VirtualLinkDf
             information element";
        }

        container ns-qos {
          presence "VL QoS parameters";
          description
            "The QoS information element specifies quality of
             service parameters applicable to a VL.";
          reference
            "GS NFV IFA014: Section 6.5.4.2 VirtualLinkDf
             information element";

          leaf latency {
            mandatory true;
            type uint32;
            units "ms";
            description
              "Specifies the maximum latency in ms.";
            reference
              "GS NFV IFA014: Section 6.5.6.2 QoS information
               element";
          }

          leaf packet-delay-variation {
            mandatory true;
            type uint32;
            units "ms";
            description
              "Specifies the maximum jitter in ms.";
            reference
              "GS NFV IFA014: Section 6.5.6.2 QoS information
               element";
          }

          leaf packet-loss-ratio {
            type decimal64 {
              fraction-digits "2";
              range "0..1.00";
            }
            description
              "Specifies the maximum packet loss ratio.";
            reference
              "GS NFV IFA014: Section 6.5.6.2 QoS information
               element";
          }

          leaf priority {
            type uint32;
            description
              "Specifies the priority level in case of
               congestion on the underlying physical links.";
            reference
              "GS NFV IFA014: Section 6.5.6.2 QoS information
               element";
          }
        }

        leaf service-availability-level {
          type enumeration {
            enum "level-1";
            enum "level-2";
            enum "level-3";
          }
          description
            "Specifies one of the three levels defined in ETSI
             ETSI GS NFV-REL 001 [i.5]
               * Level 1.
               * Level 2.
               * Level 3.";
          reference
            "GS NFV IFA014: Section 6.5.4.2 VirtualLinkDf
             information element";
        }
      }

      leaf test-access {
        type enumeration {
          enum none;
          enum passive-monitoring;
          enum active;
        }
        description
          "Specifies test access facilities expected on the VL.";
        reference
          "GS NFV IFA014: Section 6.5.2.2 NsVirtualLinkDesc
           information element";
      }

      leaf description {
        type string;
        description
          "Provides human-readable information on the purpose of
           the virtual link (e.g. VL for control plane traffic).";
        reference
          "GS NFV IFA014: Section 6.5.2.2 NsVirtualLinkDesc
           information element";
      }
      uses security-parameters;
    }

    list vnffgd {
      key "id";

      description
        "Provides the descriptors of the applicable forwarding
         graphs.";
      reference
        "GS NFV IFA014: Section 6.2.2.2 Network Service Descriptor
         information element";

      leaf id {
        type string;
        description
          "Identifier of this Vnffgd information element. It
           uniquely identifies a VNFFGD.";
        reference
          "GS NFV IFA014: Section 6.4.2.2 Vnffgd information
             element";
      }

      leaf-list vnf-profile-id {
        type leafref {
          path "../../df/vnf-profile/id";
        }
        description
          "References the VnfProfile of a constituent VNF.";
        reference
          "GS NFV IFA014: Section 6.4.2.2 Vnffgd information
           element";
      }

      leaf-list pnf-profile-id {
        type leafref {
          path "../../df/pnf-profile/id";
        }
        description
          "References the PnfProfile of a constituent PNF.";
        reference
          "GS NFV IFA014: Section 6.4.2.2 Vnffgd information
           element";
      }

      leaf-list nested-ns-profile-id {
        type leafref {
          path "../../df/ns-profile/id";
        }
        description
          "References the NsProfile of a nestedNS.";
        reference
          "GS NFV IFA014: Section 6.4.2.2 Vnffgd information
           element";
      }

      leaf virtual-link-profile-id {
        type leafref {
          path "../../df/virtual-link-profile/id";
        }
        description
          "References the Virtual Link Profile of a constituent
             VL.";
        reference
          "GS NFV IFA014: Section 6.4.2.2 Vnffgd information
           element";
      }

      list cpd-pool {
        key "id";

        description
          "Describes a pool of descriptors of connection points
           attached to one of the constituent VNFs and PNFs and/or
           one of the SAPs of the parent NS or of a nested NS.";
        reference
          "GS NFV IFA014: Section 6.4.2.2 Vnffgd information
           element";

        leaf id {
          type string;
        }

        choice constituent-base-element-id {
          mandatory "true";
          container vnf-profile {
            leaf vnf-profile-id {
              must ". = deref(../../vnfd-profile-id)" {
              }
              type leafref {
                path "../../../../../nsd/df/vnf-profile/id";
              }
            }
          }
          container pnf-profile {
            leaf pnf-profile-id {
              must ". = deref(../../pnfd-profile-id)" {
              }
              type leafref {
                path "../../../../../nsd/df/pnf-profile/id";
              }
            }
          }
          container ns-profile {
            leaf ns-profile-id {
              must ". = deref(../../ns-profile-id)" {
              }
              type leafref {
                path "../../../../../nsd/df/ns-profile/id";
              }
            }
          }
          description
            "Reference to the profile of an NS constituent.";
          reference
            "GS NFV IFA014: Section 6.4.8 CpdInConstituentElement
             information element";
        }

        choice constituent-cpd-id {
          container vnf {
            leaf vnfd-id {
              must ". = deref(../../vnfd-profile-id)/../vnfd-id" {
              }
              type leafref {
                path "../../../../../vnfd/id";
              }
            }
            leaf cpd-id {
              type leafref {
                path "deref(../vnfd-id)/../ext-cpd/id";
              }
            }
          }
          container pnf {
            leaf pnfd-id {
              must ". = deref(../../pnfd-profile-id)/../pnfd-id" {
              }
              type leafref {
                path "../../../../../pnfd/id";
              }
            }
            leaf pnf-cpd-id {
              type leafref {
                path "deref(../pnfd-id)/../ext-cpd/id";
              }
            }
          }
          container ns {
            leaf nsd-id {
              must ". = deref(../../nested-ns-profile-id)/" +
                   "../nsd-id" {
              }

              type leafref {
                path "../../../../../nsd/id";
              }
            }
            leaf sap-cpd-id {
              type leafref {
                path "deref(../nsd-id)/../sapd/id";
              }
            }
          }
          description
            "A reference to the descriptor of a connection point
             attached to one of the constituent VNFs and PNFs or to
             the descriptor of a NS SAP.";
          reference
            "GS NFV IFA014: Section 6.4.4.2 CpdPool information
             element";
        }
      }

      list nfpd {
        key "id";

        description
          "The network forwarding path associated to the VNFFG.";
        reference
          "GS NFV IFA014: Section 6.4.2.2 Vnffgd information
           element";

        leaf id {
          type string;
          description
            "Identifies this nfpd information element within a
             VNFFGD.";
          reference
            "GS NFV IFA014: Section 6.4.3.2 Nfpd information
             element";
        }

        leaf rule {
          type string;
          description
            "Provides an NFP classification and selection rule.
             The rule may be expressed as a criteria constructed
             out of atomic assertions linked by Boolean operators
             AND, OR and NOT.";
          reference
            "GS NFV IFA014: Section 6.4.3.2 Nfpd information
             element";
        }

        list position-desc-id {
          key "id";

          description
            "Describes a position in the NFP in terms of one or
             more CP profiles and rules for distributing the
             traffic among CP and SAP instances created from the
             CPD or SAPD associated to these profiles. This shall
             be connection point profile, which is either a CPD
             associated with the VnfProfile of a constituent VNF,
             or a CPD associated with the PnfProfile of a
             constituent PNF, or a SAPD associated with the
             NsProfile of a nested NS. The related VnfProfile,
             PnfProfile and NsProfile shall be included in the
             parent VNFFGD.";
          reference
            "GS NFV IFA014: Section 6.4.3.2 Nfpd information
             element";

          leaf id {
            type string;
            description
              "Identifier of this NfpPositionDesc element.";
            reference
              "GS NFV IFA014: Section 6.4.5.2 NfpPositionDesc
               information element";
          }

          list cp-profile-id {
            key "id";

            description
              "References the profile of a connection point to be
               traversed by the traffic flows matching the criteria.
               This shall be a connection point attached to one of
               the constituent VNFs and PNFs of the parent VNFFG,
               or a SAP of one of the constituent nested NSs of the
               parent VNFFG.";
            reference
              "GS NFV IFA014: Section 6.4.5.2 NfpPositionDesc
               information element";

            leaf id {
              type string;
              description
                "Identifier of this CpProfile information element.
                 It uniquely identifies a CpProfile.";
              reference
                "GS NFV IFA014: Section 6.4.6.2 CpProfile
                 information element";
            }

            list constituent-profile-elements {
              key "id";

              description
                "Specifies the constituents of the CpProfile.";
              reference
                "GS NFV IFA014: Section 6.4.6.2 CpProfile
                 information element";

              leaf id {
                type string;
                description
                  "Specifies the constituents of the CpProfile.";
                reference
                  "GS NFV IFA014: Section 6.4.7.2
                   ConstituentProfileElements information element";
              }

              leaf cpd-id {
                type string;
                description
                  "References the VNF external CPD for a given
                   VnfProfile, or the PNF external CPD for a given
                   PnfProfile, or a NS SAPD for a give NsProfile
                   identified by the constituentBasedElementId.";
                reference
                  "GS NFV IFA014: Section 6.4.7.2
                   ConstituentProfileElements information element";
              }
            }
          }
        }
      }
    }

    leaf-list autoscale-rule {
      type string;
    }
    list lifecycle-management-script {
      key "event";
      leaf event {
        type string;
      }
      leaf script {
        type string;
      }
    }

    list df {
      min-elements 1;
      must "default-instantiation-level or " +
           "count(ns-instantiation-level) = 1" {
        error-message
          "default-instantiation-level must be present if there " +
          "multiple instantion-level";
        reference
          "GS NFV IFA014: Section 6.3.2.2 NsDf information element";
      }

      key "id";
      description
        "Identifies a DF within the scope of an NSD.";
      reference
        "GS NFV IFA014: Section 6.2.2.2 Network Service Descriptor
         information element";

      leaf id {
        type string;
        description
          "Identifies this NsDf information element. It identifies
           a NS DF within the NSD.";
        reference
          "GS NFV IFA014: Section 6.3.2.2 NsDf information element";
      }

      leaf flavour-key {
        type leafref {
          path "../monitored-info/id";
        }
        description
          "Assurance parameter against which this flavour is being
           described.

           The key can be a combination of multiple assurance
           parameters with a logical relationship between them.
           The parameters should be present as a monitoredInfo
           attribute in the NSD.";
        reference
          "GS NFV IFA014: Section 6.3.2.2 NsDf information element";
      }

      list vnf-profile {
        must "min-number-of-instances <= max-number-of-instances";
        must "boolean(../../vnfd-id[.=current()/vnfd-id])" {
          error-message "VNFDs in the profile has to be listed as a " +
                        "dependency of the network service " +
                        "descriptor.";
        }
        key "id";
        description
          "VNF profile to be used for the NS flavour.";
        reference
          "GS NFV IFA014: Section 6.3.2.2 NsDf information element";

        leaf id {
          type string;
          description
            "Identifier of this vnfProfile information element. It
             uniquely identifies a VnfProfile.";
          reference
            "GS NFV IFA014: Section 6.3.3.2 VnfProfile information
             element";
        }

        leaf vnfd-id {
          mandatory true;
          type leafref {
            path "../../../../vnfd/id";
          }
          description
            "References a VNFD.";
          reference
            "GS NFV IFA014: Section 6.3.3.2 VnfProfile information
             element";
        }

        leaf flavour-id {
          mandatory true;
          type leafref {
            path "deref(../vnfd-id)/../df/id";
          }
          description
            "Identifies a flavour within the VNFD.";
          reference
            "GS NFV IFA014: Section 6.3.3.2 VnfProfile information
             element";
        }

        leaf instantiation-level {
          mandatory true;
          type leafref {
            path "deref(../flavour-id)/../instantiation-level/id";
          }
          description
            "Identifier of the instantiation level of the VNF DF
             to be used for instantiation. If not present, the
             default instantiation level as declared in the VNFD
             shall be used.";
          reference
            "GS NFV IFA014: Section 6.3.3.2 VnfProfile information
             element";
        }

        leaf min-number-of-instances {
          default 1;
          type uint16;
          description
            "Minimum number of instances of the VNF based on this
             VNFD that is permitted to exist for this VnfProfile.";
          reference
            "GS NFV IFA014: Section 6.3.3.2 VnfProfile information
             element";
        }

        leaf max-number-of-instances {
          default 1;
          type uint16;
          description
            "Maximum number of instances of the VNF based on this
             VNFD that is permitted to exist for this VnfProfile.";
          reference
            "GS NFV IFA014: Section 6.3.3.2 VnfProfile information
             element";
        }

        uses local-affinity-or-anti-affinity-rule;

        list affinity-or-anti-affinity-group {
          key "id";

          description
            "Identifier(s) of the affinity or anti-affinity
             group(s) the VnfProfile belongs to.";
          reference
            "GS NFV IFA014: Section 6.3.3.2 VnfProfile information
             element";

          leaf id {
            type leafref {
              path "../../../affinity-or-anti-affinity-group/id";
            }
          }
        }

        list virtual-link-connectivity {
          key "virtual-link-profile-id";

          description
            "Defines the connection information of the VNF, it
             contains connection relationship between a VNF
             connection point and a NS Virtual Link.";
          reference
            "GS NFV IFA014: Section 6.3.3.2 VnfProfile information
               element";

          leaf virtual-link-profile-id {
            type leafref {
              path "../../../virtual-link-profile/id";
            }
            description
              "Reference an NS VL profile.";
            reference
              "GS NFV IFA014: Section 6.3.7.2, NsVirutalLinkConnectivity
               information element.";
          }

          list constituent-cpd-id {
            key "constituent-base-element-id";

            description
              "Describes a connection point on a VNF/PNF or a SAP
               which connects to virtual links instantiated from
               the profile identified in the virtualLinkProfileId
               attribute.";
            reference
              "GS NFV IFA014: Section 6.3.7
               NsVirtualLinkConnectivity information element";

            leaf constituent-base-element-id {
              type leafref {
                path "../../../id";
              }
              description
                "Reference to the profile of an NS constituent.";
              reference
                "GS NFV IFA014: Section 6.4.8
                 CpdInConstituentElement information element";
            }

            leaf constituent-cpd-id {
              type leafref {
                path "deref(../../../vnfd-id)/../ext-cpd/id";
              }
              description
                "A reference to the descriptor of a connection point
                 attached to one of the constituent VNFs and PNFs or to
                 the descriptor of a NS SAP.";
              reference
                "GS NFV IFA014: Section 6.4.4.2 CpdPool information
                 element";
            }
          }
        }
      }

      list pnf-profile {
        key "id";
        must "boolean(../../pnfd-id[.=current()/pnfd-id])" {
          error-message "PNFDs in the profile has to be listed as a " +
                        "dependency of the network service " +
                        "descriptor.";
        }

        leaf id {
          type string;
          description
            "Identifier of this PnfProfile information element.
             It uniquely identifies a PnfProfile.";
          reference
            "GS NFV IFA014: Section 6.3.6.2 PnfProfile information
             element";
        }

        leaf pnfd-id {
          type leafref {
            path "../../../../pnfd/id";
          }
          description
            "References a PNFD.";
          reference
            "GS NFV IFA014: Section 6.3.6.2 PnfProfile information
             element";
        }

        list virtual-link-connectivity {
          key "virtual-link-profile-id";

          description
            "Defines the connection information of the PNF, it
             contains connection relationship between a PNF
             connection point and a NS Virtual Link.";
          reference
            "GS NFV IFA014: Section 6.3.6.2 PnfProfile information
             element";

          leaf virtual-link-profile-id {
            type leafref {
              path "../../../virtual-link-profile/id";
            }
            description
              "Reference an NS VL profile.";
            reference
              "GS NFV IFA014: Section 6.3.7.2, NsVirutalLinkConnectivity
               information element.";
          }

          list constituent-cpd-id {
            key "constituent-base-element-id";

            description
              "Describes a connection point on a VNF/PNF or a SAP
               which connects to virtual links instantiated from
               the profile identified in the virtualLinkProfileId
               attribute.";
            reference
              "GS NFV IFA014: Section 6.3.7
               NsVirtualLinkConnectivity information element";

            leaf constituent-base-element-id {
              type leafref {
                path "../../../id";
              }
              description
                "Reference to the profile of an NS constituent.";
              reference
                "GS NFV IFA014: Section 6.4.8
                 CpdInConstituentElement information element";
            }

            leaf constituent-cpd-id {
              type leafref {
                path "deref(../../../pnfd-id)/../ext-cpd/id";
              }
              description
                "A reference to the descriptor of a connection point
                 attached to one of the constituent VNFs and PNFs or to
                 the descriptor of a NS SAP.";
              reference
                "GS NFV IFA014: Section 6.4.4.2 CpdPool information
                 element";
            }
          }
        }
      }

      list virtual-link-profile {
        key "id";

        description
          "VL profile to be used for the NS flavour.";
        reference
          "GS NFV IFA014: Section 6.3.2.2 NsDf information element";

        leaf id {
          type string;
          description
            "Uniquely identifies this VirtualLinkProfile
             information element.";
          reference
            "GS NFV IFA014: Section 6.3.2.2 VirtualLinkProfile
             information element";
        }

        leaf virtual-link-desc-id {
          mandatory true;
          type leafref {
            path "../../../virtual-link-desc/id";
          }
          description
            "Uniquely references a VLD.";
          reference
            "GS NFV IFA014: Section 6.3.2.2 VirtualLinkProfile
             information element";
        }

        leaf flavour-id {
          mandatory true;
          type leafref {
            path "deref(../virtual-link-desc-id)/../df/id";
          }
          description
            "Identifies a flavour within the VLD.";
          reference
            "GS NFV IFA014: Section 6.3.2.2 VirtualLinkProfile
             information element";
        }

        uses local-affinity-or-anti-affinity-rule;

        list affinity-or-anti-affinity-group {
          key "id";

          description
            "Identifies an affinity or anti-affinity group the
             VLs instantiated according to the VlProfile belong
             to.";
          reference
            "GS NFV IFA014: Section 6.3.4.2 VirtualLinkProfile
             information element";

          leaf id {
            type leafref {
              path "../../../affinity-or-anti-affinity-group/id";
            }
          }
        }

        container max-bitrate-requirements {
          description
            "Specifies the maximum bitrate requirements for a VL
             instantiated according to this profile.";
          reference
            "GS NFV IFA014: Section 6.3.4.2 VirtualLinkProfile
             information element";
          uses link-bitrate-requirements;
        }
        container min-bitrate-requirements {
          description
            "Specifies the minimum bitrate requirements for a VL
             instantiated according to this profile.";
          reference
            "GS NFV IFA014: Section 6.3.4.2 VirtualLinkProfile
             information element";
          uses link-bitrate-requirements;
        }
      }

      list scaling-aspect {
        key "id";

        description
          "The scaling aspects supported by this DF of the NS.";
        reference
          "GS NFV IFA014: Section 6.3.2.2 NsDf information element";

        leaf id {
          type string;
          description
            "Identifier of this NsScalingAspect information element.
             It uniquely identifies the NS scaling aspect in an
             NSD.";
          reference
            "GS NFV IFA014: Section 6.7.2.2 NsScalingAspect
             information element";
        }

        leaf name {
          type string;
          description
            "Provides a human readable name of the NS scaling
             aspect.";
          reference
            "GS NFV IFA014: Section 6.7.2.2 NsScalingAspect
             information element";
        }

        leaf description {
          type string;
          description
            "Provides a human readable description of the NS
             scaling aspect.";
          reference
            "GS NFV IFA014: Section 6.7.2.2 NsScalingAspect
             information element";
        }

        leaf scaling-level {
          type leafref {
            path "../../ns-instantiation-level/id";
          }
          description
            "Describes the details of an NS level.";
          reference
            "GS NFV IFA014: Section 6.7.2.2 NsScalingAspect
             information element";
        }
      }

      list affinity-or-anti-affinity-group {
        key "id";

        description
          "Specifies affinity or anti-affinity relationship
           applicable between the VNF instances created using
           different VNFDs, the Virtual Link instances created
           using different NsVirtualLinkDescs or the nested NS
           instances created using different NSDs in the same
           affinity or anti-affinity group.";
        reference
          "GS NFV IFA014: Section 6.3.2.2 NsDf information element";

        leaf id {
          type string;
          description
            "Identifier of Identifier of this
             AffinityOrAntiAffinityGroup information element.";
          reference
            "GS NFV IFA014: Section 6.3.5.2 AffinityOrAntiAffinity
             information element";
        }

        leaf type {
          mandatory true;
          type affinity-type;
          description
            "Specifies the type of relationship that the members of
             the group have: 'affinity' or 'anti-affinity.'";
          reference
            "GS NFV IFA014: Section 6.3.5.2 AffinityOrAntiAffinity
             information element";
        }

        leaf scope {
          mandatory true;
          type affinity-scope;
          description
            "Specifies the scope of the affinity or anti-affinity
             relationship e.g. a NFVI node, an NFVI PoP, etc.";
          reference
            "GS NFV IFA014: Section 6.3.5.2 AffinityOrAntiAffinity
             information element";
        }
      }

      list ns-instantiation-level {
        min-elements 1;
        key "id";