Skip to content
etsi-nfv-ns.yang 57.4 KiB
Newer Older
submodule etsi-nfv-ns {
  yang-version 1.1;
Mahesh Jethanandani's avatar
Mahesh Jethanandani committed
  belongs-to etsi-nfv-descriptors {
Mahesh Jethanandani's avatar
Mahesh Jethanandani committed
  include etsi-nfv-common;
  include etsi-nfv-vnf;
  include etsi-nfv-pnf;

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

Mahesh Jethanandani's avatar
Mahesh Jethanandani committed
    description
       NSD according to ETSI GS NFV-IFA 014 Release 3.";
  revision 2020-06-01 {
    description
      "Version 2.8.1.

       NSD according to ETSI GS NFV-IFA 014 271.";
  }

Mahesh Jethanandani's avatar
Mahesh Jethanandani committed
  revision 2019-10-01 {
    description
      "Version 2.7.1.

Mahesh Jethanandani's avatar
Mahesh Jethanandani committed
       Common data structures to support NSD according to:
       ETSI GS NFV-IFA 014 Ed271v264.";
Mahesh Jethanandani's avatar
Mahesh Jethanandani committed
  }
  revision 2019-04-25 {
    description
      "Initial revision

       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;
    }
  }

Mahesh Jethanandani's avatar
Mahesh Jethanandani committed
  grouping ns-local-affinity-or-anti-affinity-rule {
    list local-affinity-or-anti-affinity-rule {
      key "type scope";

      leaf type {
        type affinity-type;
        description
          "Specifies the rule.
           Values:
             • AFFINITY
             • ANTI_AFFINITY.";
Mahesh Jethanandani's avatar
Mahesh Jethanandani committed
        reference
          "GS NFV IFA014: Section 6.3.8.2,
           LocalAffinityOrAntiAffinityRule information element.";
      }

      leaf scope {
        type affinity-scope;
        description
          "Specifies the scope of the rule.
           Values:
             • NFVI_POP
             • ZONE
             • ZONE_GROUP
             • NFVI_NODE
             • etc.";
Mahesh Jethanandani's avatar
Mahesh Jethanandani committed
        reference
          "GS NFV IFA014: Section 6.3.8.2,
           LocalAffinityOrAntiAffinityRule information element.";
      }
    }
  }
  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 {
Mahesh Jethanandani's avatar
Mahesh Jethanandani committed
        path "/nfv:nfv/nfv:vnfd/nfv: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 {
Mahesh Jethanandani's avatar
Mahesh Jethanandani committed
        path "/nfv:nfv/nfv:pnfd/nfv: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;
          "Identifier of this Cpd information element.";
          "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.";
          "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 {
Mahesh Jethanandani's avatar
Mahesh Jethanandani committed
                path "/nfv:nfv/nfv:vnfd/nfv:id";
              must "boolean(../../../vnfd-id[.=current()])";
            }
            leaf ext-cpd-id {
              mandatory true;
              type leafref {
Mahesh Jethanandani's avatar
Mahesh Jethanandani committed
                path "deref(../vnfd-id)/../nfv:ext-cpd/nfv:id";
          container pnf {
            leaf pnfd-id {
              mandatory true;
              type leafref {
Mahesh Jethanandani's avatar
Mahesh Jethanandani committed
                path "/nfv:nfv/nfv:pnfd/nfv:id";
              must "boolean(../pnfd-id[.=current()])";
            }
            leaf ext-cpd-id {
              mandatory true;
              type leafref {
Mahesh Jethanandani's avatar
Mahesh Jethanandani committed
                path "deref(../pnfd-id)/../nfv:ext-cpd/nfv: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 {
        description
          "The VirtualLinkDf information element specifies
           properties for instantiating a VL according to a
           specific flavour.";
          "GS NFV IFA014: Section 6.5.2.2 NsVirtualLinkDesc
           information element";
        leaf id {
          type string;
            "Identifies this VirtualLinkDf information element
             within a VLD.";
            "GS NFV IFA014: Section 6.5.4.2 VirtualLinkDf
             information element";
        container qos {
          presence "VL QoS parameters";
            "The QoS information element specifies quality of
             service parameters applicable to a VL.";
            "GS NFV IFA014: Section 6.5.4.2 VirtualLinkDf
             information element";

          leaf latency {
            mandatory true;
            type uint32;
            units "ms";
              "Specifies the maximum latency in ms.";
              "GS NFV IFA014: Section 6.5.6.2 QoS information
               element";
          leaf packet-delay-variation {
            mandatory true;
            type uint32;
            units "ms";
              "Specifies the maximum jitter in ms.";
              "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;
              "Specifies the priority level in case of
               congestion on the underlying physical links.";
              "GS NFV IFA014: Section 6.5.6.2 QoS information
               element";
        leaf service-availability-level {
Mahesh Jethanandani's avatar
Mahesh Jethanandani committed
          type uint32;
Mahesh Jethanandani's avatar
Mahesh Jethanandani committed
            "If present, specifies the service availability level
             for the VL instance created from this DF.

             THE FOLLOWING STATEMENT IS SUBJECT TO CHANGE:

             Either the serviceAvailabilityLevel attribute of NS DF
             or the serviceAvailabilityLevel attribute of the VL DF
             may be provided, but not both.";
            "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;
          "Provides human-readable information on the purpose of
           the virtual link (e.g. VL for control plane traffic).";
          "GS NFV IFA014: Section 6.5.2.2 NsVirtualLinkDesc
           information element";
    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
      }

      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 nfp-position-element {
Mahesh Jethanandani's avatar
Mahesh Jethanandani committed
        min-elements 1;
        leaf id {
          type string;
          description
            "Identifier of this NfpPositionElemen information
             element. It uniquely identifies an
             NfpPositionElemen.";
          reference
            "GS NFV IFA014: Section 6.4.6.2 NfpPositionElement
                 information element";
        container desc {
          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";
Mahesh Jethanandani's avatar
Mahesh Jethanandani committed
          choice constituent-cpd-id {
            container vnf {
              leaf vnfd-id {
                must ". = deref(../../vnfd-profile-id)/../vnfd-id" {
                }
                type leafref {
                  path "/nfv:nfv/nfv:vnfd/nfv:id";
                }
Mahesh Jethanandani's avatar
Mahesh Jethanandani committed
              leaf cpd-id {
                type leafref {
                  path "deref(../vnfd-id)/../nfv:ext-cpd/nfv:id";
                }
            container pnf {
              leaf pnfd-id {
                must ". = deref(../../pnfd-profile-id)/../pnfd-id" {
                }
                type leafref {
Mahesh Jethanandani's avatar
Mahesh Jethanandani committed
                  path "/nfv:nfv/nfv:pnfd/nfv:id";
Mahesh Jethanandani's avatar
Mahesh Jethanandani committed
              leaf pnf-cpd-id {
                type leafref {
                  path "deref(../pnfd-id)/../nfv:ext-cpd/nfv: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
              "References the VNF external CPD for a given
               VnfProfile, or the PNF external CPD for a given
               PnfProfile, or a NS SAPD for a given NsProfile
               identified by the constituentBaseElementId.";
            reference
              "GS NFV IFA014: Section 6.4.8.2
               CpdInConstituentElement information element";
Mahesh Jethanandani's avatar
Mahesh Jethanandani committed
            "Specifies a CPD or SAPD in the context of a profile
             of an NS constituent element.";
            "GS NFV IFA014: Section 6.4.6.2 NfpPositionElement
             information element";
          "One or a pair of CPDs or SAPDs. These descriptors
           shall be members of the CpdPool associated to the
           parent VNFFG.";
          "GS NFV IFA014: Section 6.4.5.2 NfpPositionDesc
           information element";
      }

      list nfpd {
        key "id";

        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 {
Mahesh Jethanandani's avatar
Mahesh Jethanandani committed
          min-elements 1;
          leaf id {
            type string;
            description
              "Identifier of this NfpPositionDesc element.";
              "GS NFV IFA014: Section 6.4.5.2 NfpPositionDesc
               information element";
          leaf-list nfp-position-element-id {
            type leafref {
              path "../../../nfp-position-element/id";
            description
              "References one or a pair of CPDs or SAPDs.";
Mahesh Jethanandani's avatar
Mahesh Jethanandani committed
              "GS NFV IFA014: Section 6.4.5.2 NfpPositionDesc
               information element";
          leaf forwarding-behaviour {
            type identityref {
              base forwarding-behaviour;
            }
              "Specifies a rule to apply to forward traffic to CP or
               SAP instances corresponding to the referenced CP
               profiles(s). The minimum list of rules to be supported
               shall include:
               • ALL = Traffic flows shall be forwarded simultaneously
                 to all CP or SAP instances created from the
                 referenced CP profile(s).
               • LB = Traffic flows shall be forwarded to one CP or SAP
                 instance created from the referenced CP profile(s)
                 selected based on a load-balancing algorithm
               Values:
                 • ALL
                 • LB
                 • etc.";
              "GS NFV IFA014: Section 6.4.5.2 NfpPositionDesc
               information element";
          leaf forwarding-behavior-input-parameters {
            type string;
            description
              "Provides input parameters to configure the forwarding
               behaviour (e.g. identifies a load balancing
               algorithm).";
            reference
              "GS NFV IFA014: Section 6.4.5.2 NfpPositionDesc
               information element";

          description
            "Describes a position in the NFP in terms of one or more
             CPDs and SAPDs and rules for distributing the traffic
             among CP and SAP instances created from these CPDs
             and SAPDs.";
          reference
            "GS NFV IFA014: Section 6.4.3.2 Nfpd information
             element";
        description
          "The network forwarding path associated to the VNFFG.";
        reference
          "GS NFV IFA014: Section 6.4.2.2 Vnffgd 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.";
          "GS NFV IFA014: Section 6.3.2.2 NsDf information element";

        leaf id {
          type string;
            "Identifier of this VnfProfile information element. It
             uniquely identifies a VnfProfile.";
            "GS NFV IFA014: Section 6.3.3.2 VnfProfile information
             element";
        leaf vnfd-id {
          mandatory true;
          type leafref {
Mahesh Jethanandani's avatar
Mahesh Jethanandani committed
            path "/nfv:nfv/nfv:vnfd/nfv:id";
            "References a VNFD.";
          reference
            "GS NFV IFA014: Section 6.3.3.2 VnfProfile information
             element";
        }
        leaf flavour-id {
          mandatory true;
          type leafref {
Mahesh Jethanandani's avatar
Mahesh Jethanandani committed
            path "deref(../vnfd-id)/../nfv:df/nfv:id";
            "GS NFV IFA014: Section 6.3.3.2 VnfProfile information
             element";
        leaf instantiation-level {
          mandatory true;
          type leafref {
Mahesh Jethanandani's avatar
Mahesh Jethanandani committed
            path "deref(../flavour-id)/../nfv:instantiation-level/" +
Mahesh Jethanandani's avatar
Mahesh Jethanandani committed
                 "nfv: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";
        }

Mahesh Jethanandani's avatar
Mahesh Jethanandani committed
        uses ns-local-affinity-or-anti-affinity-rule;
Mahesh Jethanandani's avatar
Mahesh Jethanandani committed
        leaf-list affinity-or-anti-affinity-group-id {
          type leafref {
            path "../../affinity-or-anti-affinity-group/id";
          }
            "Reference(s) the affinity or anti-affinity group(s)
             the VnfProfile belongs to.";
            "GS NFV IFA014: Section 6.3.3.2 VnfProfile information
             element";
        }
        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
          leaf virtual-link-profile-id {
            type leafref {
              path "../../../virtual-link-profile/id";
              "Reference an NS VL profile.";
              "GS NFV IFA014: Section 6.3.7.2, NsVirutalLinkConnectivity
               information element.";
          list constituent-cpd-id {
            key "constituent-base-element-id";
              "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.";
              "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 {
Mahesh Jethanandani's avatar
Mahesh Jethanandani committed
                path "deref(../../../vnfd-id)/../nfv:ext-cpd/nfv:id";
                "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.";
                "GS NFV IFA014: Section 6.4.4.2 CpdPool information
                 element";
Mahesh Jethanandani's avatar
Mahesh Jethanandani committed

        leaf service-availability-level {
          must "not(../../service-availability-level)";
          type uint32;
          description
            "If present, specifies the service availability level for
             the VNF instance created from this profile.

             Either the serviceAvailabilityLevel attribute of NS DF
             or the serviceAvailabilityLevel attribute of the
             VnfProfile may be provided, but not both.";
          reference
            "GS NFV IFA014: Section 6.3.3.2 VnfProfile 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 {
Mahesh Jethanandani's avatar
Mahesh Jethanandani committed
            path "/nfv:nfv/nfv:pnfd/nfv: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";
              "Reference an NS VL profile.";
              "GS NFV IFA014: Section 6.3.7.2, NsVirutalLinkConnectivity
               information element.";
          list constituent-cpd-id {
            key "constituent-base-element-id";
              "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.";
              "GS NFV IFA014: Section 6.3.7
               NsVirtualLinkConnectivity information element";
            leaf constituent-base-element-id {
              type leafref {
                path "../../../id";
                "Reference to the profile of an NS constituent.";