module openconfig-aft {

    yang-version 1;

    namespace
      "http://openconfig.net/yang/aft";

    prefix oc-aft;

    import openconfig-extensions {
      prefix oc-ext;
    }
    import ietf-inet-types {
      prefix inet;
    }
    import ietf-yang-types {
      prefix yang;
    }
    import openconfig-aft-types {
      prefix oc-aftt;
    }
    import openconfig-mpls-types {
      prefix oc-mplst;
    }
    import openconfig-interfaces {
      prefix oc-if;
    }
    import openconfig-packet-match-types {
      prefix oc-pkt-match-types;
    }
    import openconfig-policy-types {
      prefix oc-pol-types;
    }
    import openconfig-types {
      prefix oc-types;
    }

    organization "OpenConfig working group";

    contact
      "OpenConfig working group
    www.openconfig.net";

    description
      "A model describing the forwarding entries installed on a network
    element. It should be noted that this model is not expected to
    align 1:1 with the underlying structure used directly by a
    forwarding element (e.g., linecard), but rather provide an
    abstraction that can be consumed by an NMS to observe, and in some
    cases manipulate, the internal forwarding database in a simplified
    manner. Since the underlying model of the forwarding table is not
    expected to align with this model, the structure described herein
    is referred to as an Abstract Forwarding Table (AFT), rather than
    the FIB.";

    revision "2017-01-13" {
      description
        "Updated revision to address review comments";
      reference
        "0.2.1";

    }

    revision "2016-09-07" {
      description
        "Initial revision for external review";
      reference
        "0.2.0";

    }

    oc-ext:openconfig-version "0.2.1";

    grouping aft-entry-config {
      description
        "Configuration parameters relating to a forwarding entry";
      leaf index {
        type uint64;
        description
          "A unique index referring to the AFT entry";
      }
    }  // grouping aft-entry-config

    grouping aft-entry-state {
      description
        "Operational state parameters relating to a forwarding entry";
      leaf packets-forwarded {
        type yang:counter64;
        description
          "The number of packets which have matched, and been forwarded,
         based on the AFT entry.";
      }

      leaf octets-forwarded {
        type yang:counter64;
        description
          "The number of octets which have matched, and been forwarded,
         based on the AFT entry";
      }
    }  // grouping aft-entry-state

    grouping aft-entry-match-state {
      description
        "Match critiera for AFT entries";
      leaf ip-prefix {
        type inet:ip-prefix;
        description
          "The IP prefix that the forwarding entry matches. Used for
        Layer 3 forwarding entries.";
      }

      leaf mac-address {
        type yang:mac-address;
        description
          "The MAC address that the forwarding entry matches. Used for
         Layer 2 forwarding entries, e.g., within a VSI instance.";
      }

      leaf mpls-label {
        type oc-mplst:mpls-label;
        description
          "The MPLS label that the forwarding entry matches. Used for
        MPLS forwarding entries, whereby the local device acts as an
        LSR.";
      }

      leaf mpls-tc {
        type uint8 {
          range "0..7";
        }
        description
          "The value of the MPLS Traffic Class bits (formerly known as
        the MPLS experimental bits) that are to be matched by the AFT
        entry.";
        reference
          "RFC5462: Multiprotocol Label Switching (MPLS) Label Stack
          Entry: 'EXP' Field Renamed to 'Traffic Class' Field";

      }

      leaf ip-dscp {
        type inet:dscp;
        description
          "The value of the differentiated services code point (DSCP) to
        be matched for the forwarding entry. The value is specified in
        cases where specific class-based forwarding based on IP is
        implemented by the device.";
      }

      leaf ip-protocol {
        type oc-pkt-match-types:ip-protocol-type;
        description
          "The value of the IP protocol field of an IPv4 packet, or the
        next-header field of an IPv6 packet which is to be matched by
        the AFT entry. This field is utilised where forwarding is
        performed based on L4 information.";
      }

      leaf l4-src-port {
        type inet:port-number;
        description
          "The value of the source port field of the transport header
        that is to be matched by the AFT entry.";
      }

      leaf l4-dst-port {
        type inet:port-number;
        description
          "The value of the destination port field of the transport
        header that is to be matched by the AFT entry.";
      }
    }  // grouping aft-entry-match-state

    grouping aft-entry-nexthop-config {
      description
        "Configuration parameters relating to a next-hop entry for a AFT
      entry";
      leaf index {
        type uint64;
        description
          "A unique entry for the next-hop";
      }
    }  // grouping aft-entry-nexthop-config

    grouping aft-entry-nexthop-state {
      description
        "Parameters relating to a next-hop within the AFT entry";
      leaf weight {
        type uint32;
        description
          "The weight of the next-hop. Traffic is balanced according to
        the ratio described by the relative weights of the next hops
        that exist for the AFT entry. Note that all next-hops that are
        specified are assumed to be active next-hops and therefore
        eligible (and selected) to be installed in the FIB, and hence
        used for packet forwarding.";
      }

      leaf ip-address {
        type inet:ip-address-no-zone;
        description
          "The IP address of the next-hop system.";
      }

      leaf mac-address {
        type yang:mac-address;
        description
          "The MAC address of the next-hop if resolved by the local
        network instance.";
      }

      leaf-list popped-mpls-label-stack {
        type oc-mplst:mpls-label;
        description
          "The MPLS label stack to be popped from the packet when
        switched by the system. The stack is encoding as a leaf-list
        whereby the other of the entries is such that the first entry
        is the label lowest down the label stack to be popped.

        If the local system pops the outer-most label 400, then the
        value of this list is [400,]. If the local system removes two
        labels, the outer-most being 500, and the second of which is
        500, then the value of the list is [500, 400].

        A swap operation is reflected by entries in the
        popped-mpls-label-stack and pushed-mpls-label-stack nodes.";
      }

      leaf-list pushed-mpls-label-stack {
        type oc-mplst:mpls-label;
        ordered-by user;
        description
          "The MPLS label stack imposed when forwarding packets to the
        next-hop
        - the stack is encoded as a leaf list whereby the order of the
          entries is such that the first entry in the list is the
          label at the bottom of the stack to be pushed.

        To this end, a packet which is to forwarded to a device using
        a service label of 42, and a transport label of 8072 will be
        represented with a label stack list of [42, 8072].

        The MPLS label stack list is ordered by the user, such that no
        system re-ordering of leaves is permitted by the system.

        A swap operation is reflected by entries in the
        popped-mpls-label-stack and pushed-mpls-label-stack nodes.";
      }

      leaf decapsulate-header {
        type oc-aftt:encapsulation-header-type;
        description
          "When forwarding a packet to the specified next-hop, the local
        system performs a decapsulation of the packet - removing the
        specified header type. In the case that no next-hop is
        specified, the packet header is removed, and a subsequent
        forwarding lookup is performed on the packet encapsulated
        within the header, matched within the relevant AFT within the
        specified network-instance.";
      }

      leaf encapsulate-header {
        type oc-aftt:encapsulation-header-type;
        description
          "When forwarding a packet to the specified next-hop the local
        system performs an encapsulation of the packet - adding the
        specified header type.";
      }

      leaf origin-protocol {
        type identityref {
          base oc-pol-types:INSTALL_PROTOCOL_TYPE;
        }
        description
          "The protocol from which the AFT entry was learned.";
      }
    }  // grouping aft-entry-nexthop-state

    grouping aft-config {
      description
        "Configuration parameters relating to an Abstract Forwarding
      Table (AFT) for a particular address family.";
      leaf address-family {
        type identityref {
          base oc-types:ADDRESS_FAMILY;
        }
        description
          "The address family of entries that are described by the
        AFT.";
      }
    }  // grouping aft-config

    grouping aft-proto-top {
      description
        "Top level per-protocol grouping for the AFT.";
      container entries {
        description
          "Enclosing container for a list of abstract forwarding table
        entries within the network instance for a particular protocol
        (e.g., IPv4, IPv6, MPLS).";
        list entry {
          key "index";
          description
            "A forwarding database entry within the network instance";
          leaf index {
            type leafref {
              path "../config/index";
            }
            description
              "A pointer to the index of the AFT entry within the
            network instance";
          }

          container config {
            description
              "Configuration parameters relating to the forwarding
            entry";
            uses aft-entry-config;
          }  // container config

          container state {
            config false;
            description
              "Operational state parameters relating to the forwarding
            entry";
            uses aft-entry-config;

            uses aft-entry-state;
          }  // container state

          container match {
            description
              "Match criteria for the AFT entry";
            container config {
              description
                "Configuration of match criteria for the AFT entry";
            }  // container config

            container state {
              config false;
              description
                "Operational state parameters for match criteria of the
              AFT entry";
              uses aft-entry-match-state;
            }  // container state

            uses oc-if:interface-ref-state;
          }  // container match

          container next-hops {
            description
              "Enclosing container for the list of next-hops associated
            with the forwarding entry";
            list next-hop {
              key "index";
              description
                "A next-hop associated with the forwarding instance. The
              entries within the next-hop list should only reflect
              next-hops that are actively used by the local system.
              That is to say inactive, backup or FRR next-hops should
              not be included within this list.";
              leaf index {
                type leafref {
                  path "../config/index";
                }
                description
                  "A unique index identifying the next-hop entry for the
                AFT entry";
              }

              container config {
                description
                  "Configuration parameters relating to the AFT next-hop
                entry";
                uses aft-entry-nexthop-config;
              }  // container config

              container state {
                config false;
                description
                  "Operational state parameters relating to the AFT
                next-hop entry";
                uses aft-entry-nexthop-config;

                uses aft-entry-nexthop-state;
              }  // container state

              uses oc-if:interface-ref;
            }  // list next-hop
          }  // container next-hops
        }  // list entry
      }  // container entries
    }  // grouping aft-proto-top

    grouping aft-top {
      description
        "Top-level grouping allowing per-protocol instantiation of the
      AFT.";
      container afts {
        description
          "The abstract forwarding tables (AFTs) that are associated
        with the network instance. An AFT is instantiated per-protocol
        running within the network-instance - such that one exists for
        IPv4 Unicast, IPv6 Unicast, MPLS, L2 forwarding entries, etc.
        A forwarding entry within the FIB has a set of next-hops,
        which may be a reference to an entry within another table -
        e.g., where a Layer 3 next-hop has an associated Layer 2
        forwarding entry.";
        list aft {
          key "address-family";
          description
            "An individual abstract forwarding table associated with a
           an address family wtihin the network instance.";
          leaf address-family {
            type leafref {
              path
                "../config/address-family";
            }
            description
              "Reference to the address family with which the AFT is
            associated";
          }

          container config {
            description
              "Configuration parameters relating to the AFT.";
            uses aft-config;
          }  // container config

          container state {
            config false;
            description
              "Operational state parameters relating to the AFT.";
            uses aft-config;
          }  // container state

          uses aft-proto-top;
        }  // list aft
      }  // container afts
    }  // grouping aft-top
  }  // module openconfig-aft