module ietf-vpn-common {

    yang-version 1.1;

    namespace
      "urn:ietf:params:xml:ns:yang:ietf-vpn-common";

    prefix vpn-common;

    import ietf-netconf-acm {
      prefix nacm;
      reference
        "RFC 8341: Network Configuration Access Control Model";


    }
    import ietf-routing-types {
      prefix rt-types;
      reference
        "RFC 8294: Common YANG Data Types for the Routing Area";


    }
    import ietf-yang-types {
      prefix yang;
      reference
        "RFC 6991: Common YANG Data Types, Section 3";


    }
    import ietf-packet-fields {
      prefix packet-fields;
      reference
        "RFC 8519: YANG Data Model for Network Access
        	  Control Lists (ACLs)";


    }

    organization
      "IETF OPSAWG (Operations and Management Area Working Group)";

    contact
      "WG Web:   <https://datatracker.ietf.org/wg/opsawg/>
WG List:  <mailto:opsawg@ietf.org>

Editor:   Mohamed Boucadair
	  <mailto:mohamed.boucadair@orange.com>
Author:   Samier Barguil
	  <mailto:samier.barguilgiraldo.ext@telefonica.com>
Editor:   Oscar Gonzalez de Dios
	  <mailto:oscar.gonzalezdedios@telefonica.com>
Author:   Qin Wu
	  <mailto:bill.wu@huawei.com>";

    description
      "This YANG module defines a common module that is meant
to be reused by various VPN-related modules (e.g., the
Layer 3 VPN Service Model (L3SM), the Layer 2 VPN Service
Model (L2SM), the Layer 3 VPN Network Model (L3NM), and
the Layer 2 VPN Network Model (L2NM)).

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

Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject to
the license terms contained in, the 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 9181; see the
RFC itself for full legal notices.";

    revision "2022-02-11" {
      description "Initial revision.";
      reference
        "RFC 9181: A Common YANG Data Model for Layer 2 and Layer 3
        	  VPNs";

    }


    feature dot1q {
      description
        "Indicates support for dot1Q encapsulation.";
      reference
        "IEEE Std 802.1Q: IEEE Standard for Local and Metropolitan
        		 Area Networks--Bridges and Bridged
        		 Networks";

    }

    feature qinq {
      description
        "Indicates support for QinQ encapsulation.";
      reference
        "IEEE Std 802.1ad: IEEE Standard for Local and Metropolitan
        		  Area Networks---Virtual Bridged Local
        		  Area Networks---Amendment 4: Provider
        		  Bridges";

    }

    feature vxlan {
      description
        "Indicates support for Virtual eXtensible Local Area
Network (VXLAN) encapsulation.";
      reference
        "RFC 7348: Virtual eXtensible Local Area Network (VXLAN):
        	  A Framework for Overlaying Virtualized Layer 2
        	  Networks over Layer 3 Networks";

    }

    feature qinany {
      description
        "Indicates support for QinAny encapsulation.
The outer VLAN tag is set to a specific value, but
the inner VLAN tag is set to any.";
    }

    feature lag-interface {
      description
        "Indicates support for Link Aggregation Groups (LAGs)
between VPN network accesses.";
      reference
        "IEEE Std 802.1AX: IEEE Standard for Local and Metropolitan
        		  Area Networks--Link Aggregation";

    }

    feature multicast {
      description
        "Indicates support for multicast capabilities in a VPN.";
      reference
        "RFC 6513: Multicast in MPLS/BGP IP VPNs";

    }

    feature igmp {
      description
        "Indicates support for the Internet Group Management
Protocol (IGMP).";
      reference
        "RFC 1112: Host Extensions for IP Multicasting
         RFC 2236: Internet Group Management Protocol, Version 2
         RFC 3376: Internet Group Management Protocol, Version 3";

    }

    feature mld {
      description
        "Indicates support for Multicast Listener Discovery (MLD).";
      reference
        "RFC 2710: Multicast Listener Discovery (MLD) for IPv6
         RFC 3810: Multicast Listener Discovery Version 2 (MLDv2)
        	  for IPv6";

    }

    feature pim {
      description
        "Indicates support for Protocol Independent Multicast
(PIM).";
      reference
        "RFC 7761: Protocol Independent Multicast - Sparse Mode
        	  (PIM-SM): Protocol Specification (Revised)";

    }

    feature ipv4 {
      description
        "Indicates IPv4 support in a VPN.  That is, IPv4 traffic
can be carried in the VPN, IPv4 addresses/prefixes can
be assigned to a VPN network access, IPv4 routes can be
installed for the Customer Edge to Provider Edge (CE-PE)
link, etc.";
      reference
        "RFC 791: Internet Protocol";

    }

    feature ipv6 {
      description
        "Indicates IPv6 support in a VPN.  That is, IPv6 traffic
can be carried in the VPN, IPv6 addresses/prefixes can
be assigned to a VPN network access, IPv6 routes can be
installed for the CE-PE link, etc.";
      reference
        "RFC 8200: Internet Protocol, Version 6 (IPv6)
        	  Specification";

    }

    feature rtg-ospf {
      description
        "Indicates support for OSPF as the Provider Edge to
Customer Edge (PE-CE) routing protocol.";
      reference
        "RFC 4577: OSPF as the Provider/Customer Edge Protocol
        	  for BGP/MPLS IP Virtual Private Networks (VPNs)
         RFC 6565: OSPFv3 as a Provider Edge to Customer Edge
        	  (PE-CE) Routing Protocol";

    }

    feature rtg-ospf-sham-link {
      description
        "Indicates support for OSPF sham links.";
      reference
        "RFC 4577: OSPF as the Provider/Customer Edge Protocol
        	  for BGP/MPLS IP Virtual Private Networks (VPNs),
        	  Section 4.2.7
         RFC 6565: OSPFv3 as a Provider Edge to Customer Edge
        	  (PE-CE) Routing Protocol, Section 5";

    }

    feature rtg-bgp {
      description
        "Indicates support for BGP as the PE-CE routing protocol.";
      reference
        "RFC 4271: A Border Gateway Protocol 4 (BGP-4)";

    }

    feature rtg-rip {
      description
        "Indicates support for RIP as the PE-CE routing protocol.";
      reference
        "RFC 2453: RIP Version 2
         RFC 2080: RIPng for IPv6";

    }

    feature rtg-isis {
      description
        "Indicates support for IS-IS as the PE-CE routing
protocol.";
      reference
        "ISO10589: Information technology - Telecommunications and
        	  information exchange between systems -
        	  Intermediate System to Intermediate System
        	  intra-domain routeing information exchange
        	  protocol for use in conjunction with the protocol
        	  for providing the connectionless-mode network
        	  service (ISO 8473)";

    }

    feature rtg-vrrp {
      description
        "Indicates support for the Virtual Router Redundancy
Protocol (VRRP) in the CE-PE link.";
      reference
        "RFC 5798: Virtual Router Redundancy Protocol (VRRP)
        	  Version 3 for IPv4 and IPv6";

    }

    feature bfd {
      description
        "Indicates support for Bidirectional Forwarding Detection
(BFD) between the CE and the PE.";
      reference
        "RFC 5880: Bidirectional Forwarding Detection (BFD)";

    }

    feature bearer-reference {
      description
        "A bearer refers to properties of the CE-PE attachment that
are below Layer 3.
This feature indicates support for the bearer reference
access constraint, i.e., the reuse of a network connection
that was already ordered to the service provider apart from
the IP VPN site.";
    }

    feature placement-diversity {
      description
        "Indicates support for placement diversity constraints in
the customer premises.  An example of these constraints
may be to avoid connecting a site network access to the
same PE as a target site network access.";
    }

    feature qos {
      description
        "Indicates support for Classes of Service (CoSes) in
the VPN.";
    }

    feature inbound-bw {
      description
        "Indicates support for the inbound bandwidth in a VPN,
i.e., support for specifying the download bandwidth from
the service provider network to the VPN site.  Note that
the L3SM uses 'input' to identify the same feature.
That terminology should be deprecated in favor of
the terminology defined in this module.";
    }

    feature outbound-bw {
      description
        "Indicates support for the outbound bandwidth in a VPN,
i.e., support for specifying the upload bandwidth from
the VPN site to the service provider network.  Note that
the L3SM uses 'output' to identify the same feature.
That terminology should be deprecated in favor of the
terminology defined in this module.";
    }

    feature encryption {
      description
        "Indicates support for encryption in the VPN.";
    }

    feature fast-reroute {
      description
        "Indicates support for Fast Reroute (FRR) capabilities for
a VPN site.";
    }

    feature external-connectivity {
      description
        "Indicates support for the VPN to provide external
connectivity (e.g., Internet, private or public cloud).";
      reference
        "RFC 4364: BGP/MPLS IP Virtual Private Networks
        	  (VPNs), Section 11";

    }

    feature extranet-vpn {
      description
        "Indicates support for extranet VPNs, i.e., the capability
of a VPN to access a list of other VPNs.";
      reference
        "RFC 4364: BGP/MPLS IP Virtual Private Networks
        	  (VPNs), Section 1.1";

    }

    feature carriers-carrier {
      description
        "Indicates support for Carriers' Carriers in VPNs.";
      reference
        "RFC 4364: BGP/MPLS IP Virtual Private Networks
        	  (VPNs), Section 9";

    }

    identity address-family {
      description
        "Defines a type for the address family.";
    }

    identity ipv4 {
      base address-family;
      description
        "Identity for an IPv4 address family.";
    }

    identity ipv6 {
      base address-family;
      description
        "Identity for an IPv6 address family.";
    }

    identity dual-stack {
      base address-family;
      description
        "Identity for IPv4 and IPv6 address families.";
    }

    identity vpn-topology {
      description
        "Base identity of the VPN topology.";
    }

    identity any-to-any {
      base vpn-topology;
      description
        "Identity for any-to-any VPN topology.  All VPN sites
can communicate with each other without any restrictions.";
    }

    identity hub-spoke {
      base vpn-topology;
      description
        "Identity for Hub-and-Spoke VPN topology.  All Spokes can
communicate with Hubs only and not with each other.  Hubs
can communicate with each other.";
    }

    identity hub-spoke-disjoint {
      base vpn-topology;
      description
        "Identity for Hub-and-Spoke VPN topology where Hubs cannot
communicate with each other.";
    }

    identity custom {
      base vpn-topology;
      description
        "Identity for custom VPN topologies where the role of the
nodes is not strictly Hub or Spoke.  The VPN topology is
controlled by the import/export policies.  The custom
topology reflects more complex VPN nodes, such as a
VPN node that acts as a Hub for certain nodes and a Spoke
for others.";
    }

    identity site-network-access-type {
      description
        "Base identity for site network access types.";
    }

    identity point-to-point {
      base site-network-access-type;
      description
        "Point-to-point access type.";
    }

    identity multipoint {
      base site-network-access-type;
      description "Multipoint access type.";
    }

    identity irb {
      base site-network-access-type;
      description
        "Integrated Routing and Bridging (IRB).
Identity for pseudowire connections.";
    }

    identity loopback {
      base site-network-access-type;
      description "Loopback access type.";
    }

    identity operational-status {
      description
        "Base identity for operational status.";
    }

    identity op-up {
      base operational-status;
      description
        "Operational status is Up/Enabled.";
    }

    identity op-down {
      base operational-status;
      description
        "Operational status is Down/Disabled.";
    }

    identity op-unknown {
      base operational-status;
      description
        "Operational status is Unknown.";
    }

    identity administrative-status {
      description
        "Base identity for administrative status.";
    }

    identity admin-up {
      base administrative-status;
      description
        "Administrative status is Up/Enabled.";
    }

    identity admin-down {
      base administrative-status;
      description
        "Administrative status is Down/Disabled.";
    }

    identity admin-testing {
      base administrative-status;
      description
        "Administrative status is Up for testing purposes.";
    }

    identity admin-pre-deployment {
      base administrative-status;
      description
        "Administrative status reflects a pre-deployment phase,
i.e., prior to the actual deployment of a service.";
    }

    identity role {
      description
        "Base identity of a site or node role.";
    }

    identity any-to-any-role {
      base role;
      description "Any-to-any role.";
    }

    identity spoke-role {
      base role;
      description
        "A node or a site is acting as a Spoke.";
    }

    identity hub-role {
      base role;
      description
        "A node or a site is acting as a Hub.";
    }

    identity custom-role {
      base role;
      description
        "VPN node with a custom or complex role in the VPN.  For
some sources/destinations, it can behave as a Hub, but for
others, it can act as a Spoke, depending on the configured
policy.";
    }

    identity placement-diversity {
      description
        "Base identity for access placement constraints.";
    }

    identity bearer-diverse {
      base placement-diversity;
      description
        "Bearer diversity.

The bearers should not use common elements.";
    }

    identity pe-diverse {
      base placement-diversity;
      description "PE diversity.";
    }

    identity pop-diverse {
      base placement-diversity;
      description
        "Point of Presence (POP) diversity.";
    }

    identity linecard-diverse {
      base placement-diversity;
      description "Linecard diversity.";
    }

    identity same-pe {
      base placement-diversity;
      description
        "Having sites connected on the same PE.";
    }

    identity same-bearer {
      base placement-diversity;
      description
        "Having sites connected using the same bearer.";
    }

    identity service-type {
      description
        "Base identity for service types.";
    }

    identity l3vpn {
      base service-type;
      description "L3VPN service.";
      reference
        "RFC 4364: BGP/MPLS IP Virtual Private Networks (VPNs)";

    }

    identity vpls {
      base service-type;
      description
        "Virtual Private LAN Service (VPLS).";
      reference
        "RFC 4761: Virtual Private LAN Service (VPLS) Using BGP for
        	  Auto-Discovery and Signaling
         RFC 4762: Virtual Private LAN Service (VPLS) Using Label
        	  Distribution Protocol (LDP) Signaling";

    }

    identity vpws {
      base service-type;
      description
        "Virtual Private Wire Service (VPWS).";
      reference
        "RFC 4664: Framework for Layer 2 Virtual Private Networks
        	  (L2VPNs), Section 3.1.1";

    }

    identity vpws-evpn {
      base service-type;
      description
        "Ethernet VPN (EVPN) used to support VPWS.";
      reference
        "RFC 8214: Virtual Private Wire Service Support in
        	  Ethernet VPN";

    }

    identity pbb-evpn {
      base service-type;
      description
        "Provider Backbone Bridging (PBB) EVPN service.";
      reference
        "RFC 7623: Provider Backbone Bridging Combined with
        	  Ethernet VPN (PBB-EVPN)";

    }

    identity mpls-evpn {
      base service-type;
      description "MPLS-based EVPN service.";
      reference
        "RFC 7432: BGP MPLS-Based Ethernet VPN";

    }

    identity vxlan-evpn {
      base service-type;
      description
        "VXLAN-based EVPN service.";
      reference
        "RFC 8365: A Network Virtualization Overlay Solution Using
        	  Ethernet VPN (EVPN)";

    }

    identity vpn-signaling-type {
      description
        "Base identity for VPN signaling types.";
    }

    identity bgp-signaling {
      base vpn-signaling-type;
      description
        "Layer 2 VPNs using BGP signaling.";
      reference
        "RFC 6624: Layer 2 Virtual Private Networks Using BGP for
        	  Auto-Discovery and Signaling
         RFC 7432: BGP MPLS-Based Ethernet VPN";

    }

    identity ldp-signaling {
      base vpn-signaling-type;
      description
        "Targeted Label Distribution Protocol (LDP) signaling.";
      reference
        "RFC 5036: LDP Specification";

    }

    identity l2tp-signaling {
      base vpn-signaling-type;
      description
        "Layer Two Tunneling Protocol (L2TP) signaling.";
      reference
        "RFC 3931: Layer Two Tunneling Protocol - Version 3 (L2TPv3)";

    }

    identity routing-protocol-type {
      description
        "Base identity for routing protocol types.";
    }

    identity static-routing {
      base routing-protocol-type;
      description "Static routing protocol.";
    }

    identity bgp-routing {
      base routing-protocol-type;
      description "BGP routing protocol.";
      reference
        "RFC 4271: A Border Gateway Protocol 4 (BGP-4)";

    }

    identity ospf-routing {
      base routing-protocol-type;
      description "OSPF routing protocol.";
      reference
        "RFC 4577: OSPF as the Provider/Customer Edge Protocol
        	  for BGP/MPLS IP Virtual Private Networks (VPNs)
         RFC 6565: OSPFv3 as a Provider Edge to Customer Edge
        	  (PE-CE) Routing Protocol";

    }

    identity rip-routing {
      base routing-protocol-type;
      description "RIP routing protocol.";
      reference
        "RFC 2453: RIP Version 2
         RFC 2080: RIPng for IPv6";

    }

    identity isis-routing {
      base routing-protocol-type;
      description "IS-IS routing protocol.";
      reference
        "ISO10589: Information technology - Telecommunications and
        	  information exchange between systems -
        	  Intermediate System to Intermediate System
        	  intra-domain routeing information exchange
        	  protocol for use in conjunction with the protocol
        	  for providing the connectionless-mode network
        	  service (ISO 8473)";

    }

    identity vrrp-routing {
      base routing-protocol-type;
      description
        "VRRP protocol.

This is to be used when LANs are directly connected to
PEs.";
      reference
        "RFC 5798: Virtual Router Redundancy Protocol (VRRP)
        	  Version 3 for IPv4 and IPv6";

    }

    identity direct-routing {
      base routing-protocol-type;
      description
        "Direct routing.

This is to be used when LANs are directly connected to PEs
and must be advertised in the VPN.";
    }

    identity any-routing {
      base routing-protocol-type;
      description
        "Any routing protocol.

For example, this can be used to set policies that apply
to any routing protocol in place.";
    }

    identity isis-level {
      description
        "Base identity for the IS-IS level.";
      reference
        "ISO10589: Information technology - Telecommunications and
        	  information exchange between systems -
        	  Intermediate System to Intermediate System
        	  intra-domain routeing information exchange
        	  protocol for use in conjunction with the protocol
        	  for providing the connectionless-mode network
        	  service (ISO 8473)";

    }

    identity level-1 {
      base isis-level;
      description "IS-IS Level 1.";
    }

    identity level-2 {
      base isis-level;
      description "IS-IS Level 2.";
    }

    identity level-1-2 {
      base isis-level;
      description "IS-IS Levels 1 and 2.";
    }

    identity bfd-session-type {
      description
        "Base identity for the BFD session type.";
    }

    identity classic-bfd {
      base bfd-session-type;
      description "Classic BFD.";
      reference
        "RFC 5880: Bidirectional Forwarding Detection (BFD)";

    }

    identity s-bfd {
      base bfd-session-type;
      description "Seamless BFD.";
      reference
        "RFC 7880: Seamless Bidirectional Forwarding Detection
        	  (S-BFD)";

    }

    identity ie-type {
      description
        "Base identity for import/export routing profiles.
These profiles can be reused between VPN nodes.";
    }

    identity import {
      base ie-type;
      description "Import routing profile.";
      reference
        "RFC 4364: BGP/MPLS IP Virtual Private Networks
        	  (VPNs), Section 4.3.1";

    }

    identity export {
      base ie-type;
      description "Export routing profile.";
      reference
        "RFC 4364: BGP/MPLS IP Virtual Private Networks
        	  (VPNs), Section 4.3.1";

    }

    identity import-export {
      base ie-type;
      description
        "Import/export routing profile.";
    }

    identity bw-direction {
      description
        "Base identity for the bandwidth direction.";
    }

    identity inbound-bw {
      base bw-direction;
      description "Inbound bandwidth.";
    }

    identity outbound-bw {
      base bw-direction;
      description "Outbound bandwidth.";
    }

    identity bw-type {
      description
        "Base identity for the bandwidth type.";
    }

    identity bw-per-cos {
      base bw-type;
      description
        "The bandwidth is per CoS.";
    }

    identity bw-per-port {
      base bw-type;
      description
        "The bandwidth is per a given site network access.";
    }

    identity bw-per-site {
      base bw-type;
      description
        "The bandwidth is per site.  It is applicable to all the
site network accesses within a site.";
    }

    identity bw-per-service {
      base bw-type;
      description
        "The bandwidth is per VPN service.";
    }

    identity qos-profile-direction {
      description
        "Base identity for the QoS profile direction.";
    }

    identity site-to-wan {
      base qos-profile-direction;
      description
        "From the customer site to the provider's network.
This is typically the CE-to-PE direction.";
    }

    identity wan-to-site {
      base qos-profile-direction;
      description
        "From the provider's network to the customer site.
This is typically the PE-to-CE direction.";
    }

    identity both {
      base qos-profile-direction;
      description
        "Both the WAN-to-site direction and the site-to-WAN
direction.";
    }

    identity transport-instance-type {
      description
        "Base identity for underlay transport instance types.";
    }

    identity virtual-network {
      base transport-instance-type;
      description "Virtual network.";
      reference
        "RFC 8453: Framework for Abstraction and Control of TE
        	  Networks (ACTN)";

    }

    identity enhanced-vpn {
      base transport-instance-type;
      description
        "Enhanced VPN (VPN+).  VPN+ is an approach that is
based on existing VPN and Traffic Engineering (TE)
technologies but adds characteristics that specific
services require over and above classical VPNs.";
      reference
        "draft-ietf-teas-enhanced-vpn-09:
          A Framework for Enhanced Virtual Private Network
          (VPN+) Services";

    }

    identity ietf-network-slice {
      base transport-instance-type;
      description
        "IETF network slice.  An IETF network slice
is a logical network topology connecting a number of
endpoints using a set of shared or dedicated network
resources that are used to satisfy specific service
objectives.";
      reference
        "draft-ietf-teas-ietf-network-slices-05:
          Framework for IETF Network Slices";

    }

    identity protocol-type {
      description
        "Base identity for protocol types.";
    }

    identity ip-in-ip {
      base protocol-type;
      description
        "Transport is based on IP in IP.";
      reference
        "RFC 2003: IP Encapsulation within IP
         RFC 2473: Generic Packet Tunneling in IPv6 Specification";

    }

    identity ip-in-ipv4 {
      base ip-in-ip;
      description
        "Transport is based on IP over IPv4.";
      reference
        "RFC 2003: IP Encapsulation within IP";

    }

    identity ip-in-ipv6 {
      base ip-in-ip;
      description
        "Transport is based on IP over IPv6.";
      reference
        "RFC 2473: Generic Packet Tunneling in IPv6 Specification";

    }

    identity gre {
      base protocol-type;
      description
        "Transport is based on Generic Routing Encapsulation
(GRE).";
      reference
        "RFC 1701: Generic Routing Encapsulation (GRE)
         RFC 1702: Generic Routing Encapsulation over IPv4 networks
         RFC 7676: IPv6 Support for Generic Routing Encapsulation
        	  (GRE)";

    }

    identity gre-v4 {
      base gre;
      description
        "Transport is based on GRE over IPv4.";
      reference
        "RFC 1702: Generic Routing Encapsulation over IPv4
        	  networks";

    }

    identity gre-v6 {
      base gre;
      description
        "Transport is based on GRE over IPv6.";
      reference
        "RFC 7676: IPv6 Support for Generic Routing Encapsulation
        	  (GRE)";

    }

    identity vxlan-trans {
      base protocol-type;
      description
        "Transport is based on VXLANs.";
      reference
        "RFC 7348: Virtual eXtensible Local Area Network (VXLAN):
        	  A Framework for Overlaying Virtualized Layer 2
        	  Networks over Layer 3 Networks";

    }

    identity geneve {
      base protocol-type;
      description
        "Transport is based on Generic Network Virtualization
Encapsulation (Geneve).";
      reference
        "RFC 8926: Geneve: Generic Network Virtualization
        	  Encapsulation";

    }

    identity ldp {
      base protocol-type;
      description
        "Transport is based on LDP.";
      reference
        "RFC 5036: LDP Specification";

    }

    identity mpls-in-udp {
      base protocol-type;
      description
        "Transport is based on MPLS in UDP.";
      reference
        "RFC 7510: Encapsulating MPLS in UDP";

    }

    identity sr {
      base protocol-type;
      description
        "Transport is based on Segment Routing (SR).";
      reference
        "RFC 8660: Segment Routing with the MPLS Data Plane
         RFC 8663: MPLS Segment Routing over IP
         RFC 8754: IPv6 Segment Routing Header (SRH)";

    }

    identity sr-mpls {
      base sr;
      description
        "Transport is based on SR with the MPLS data plane.";
      reference
        "RFC 8660: Segment Routing with the MPLS Data Plane";

    }

    identity srv6 {
      base sr;
      description
        "Transport is based on SR over IPv6.";
      reference
        "RFC 8754: IPv6 Segment Routing Header (SRH)";

    }

    identity sr-mpls-over-ip {
      base sr;
      description
        "Transport is based on SR over MPLS over IP.";
      reference
        "RFC 8663: MPLS Segment Routing over IP";

    }

    identity rsvp-te {
      base protocol-type;
      description
        "Transport setup relies upon RSVP-TE.";
      reference
        "RFC 3209: RSVP-TE: Extensions to RSVP for LSP Tunnels";

    }

    identity bgp-lu {
      base protocol-type;
      description
        "Transport setup relies upon BGP-based labeled prefixes.";
      reference
        "RFC 8277: Using BGP to Bind MPLS Labels to Address Prefixes";

    }

    identity unknown {
      base protocol-type;
      description "Unknown protocol type.";
    }

    identity encapsulation-type {
      description
        "Base identity for encapsulation types.";
    }

    identity priority-tagged {
      base encapsulation-type;
      description
        "Priority-tagged interface.";
    }

    identity dot1q {
      base encapsulation-type;
      description "dot1Q encapsulation.";
    }

    identity qinq {
      base encapsulation-type;
      description "QinQ encapsulation.";
    }

    identity qinany {
      base encapsulation-type;
      description "QinAny encapsulation.";
    }

    identity vxlan {
      base encapsulation-type;
      description "VXLAN encapsulation.";
    }

    identity ethernet-type {
      base encapsulation-type;
      description
        "Ethernet encapsulation type.";
    }

    identity vlan-type {
      base encapsulation-type;
      description "VLAN encapsulation type.";
    }

    identity untagged-int {
      base encapsulation-type;
      description "Untagged interface type.";
    }

    identity tagged-int {
      base encapsulation-type;
      description "Tagged interface type.";
    }

    identity lag-int {
      base encapsulation-type;
      description "LAG interface type.";
    }

    identity tag-type {
      description
        "Base identity for VLAN tag types.";
    }

    identity c-vlan {
      base tag-type;
      description
        "Indicates a Customer VLAN (C-VLAN) tag, normally using
the 0x8100 Ethertype.";
    }

    identity s-vlan {
      base tag-type;
      description
        "Indicates a Service VLAN (S-VLAN) tag.";
    }

    identity s-c-vlan {
      base tag-type;
      description
        "Uses both an S-VLAN tag and a C-VLAN tag.";
    }

    identity vxlan-peer-mode {
      description
        "Base identity for VXLAN peer modes.";
    }

    identity static-mode {
      base vxlan-peer-mode;
      description
        "VXLAN access in the static mode.";
    }

    identity bgp-mode {
      base vxlan-peer-mode;
      description
        "VXLAN access by BGP EVPN learning.";
    }

    identity multicast-gp-address-mapping {
      description
        "Base identity for multicast group mapping types.";
    }

    identity static-mapping {
      base multicast-gp-address-mapping;
      description
        "Static mapping, i.e., an interface is attached to the
multicast group as a static member.";
    }

    identity dynamic-mapping {
      base multicast-gp-address-mapping;
      description
        "Dynamic mapping, i.e., an interface is added to the
multicast group as a result of snooping.";
    }

    identity multicast-tree-type {
      description
        "Base identity for multicast tree types.";
    }

    identity ssm-tree-type {
      base multicast-tree-type;
      description
        "Source-Specific Multicast (SSM) tree type.";
    }

    identity asm-tree-type {
      base multicast-tree-type;
      description
        "Any-Source Multicast (ASM) tree type.";
    }

    identity bidir-tree-type {
      base multicast-tree-type;
      description "Bidirectional tree type.";
    }

    identity multicast-rp-discovery-type {
      description
        "Base identity for Rendezvous Point (RP) discovery types.";
    }

    identity auto-rp {
      base multicast-rp-discovery-type;
      description "Auto-RP discovery type.";
    }

    identity static-rp {
      base multicast-rp-discovery-type;
      description "Static type.";
    }

    identity bsr-rp {
      base multicast-rp-discovery-type;
      description
        "Bootstrap Router (BSR) discovery type.";
    }

    identity group-management-protocol {
      description
        "Base identity for multicast group management protocols.";
    }

    identity igmp-proto {
      base group-management-protocol;
      description "IGMP.";
      reference
        "RFC 1112: Host Extensions for IP Multicasting
         RFC 2236: Internet Group Management Protocol, Version 2
         RFC 3376: Internet Group Management Protocol, Version 3";

    }

    identity mld-proto {
      base group-management-protocol;
      description "MLD.";
      reference
        "RFC 2710: Multicast Listener Discovery (MLD) for IPv6
         RFC 3810: Multicast Listener Discovery Version 2 (MLDv2)
        	  for IPv6";

    }

    identity pim-proto {
      base routing-protocol-type;
      description "PIM.";
      reference
        "RFC 7761: Protocol Independent Multicast - Sparse Mode
        	  (PIM-SM): Protocol Specification (Revised)";

    }

    identity igmp-version {
      description
        "Base identity for indicating the IGMP version.";
    }

    identity igmpv1 {
      base igmp-version;
      description "IGMPv1.";
      reference
        "RFC 1112: Host Extensions for IP Multicasting";

    }

    identity igmpv2 {
      base igmp-version;
      description "IGMPv2.";
      reference
        "RFC 2236: Internet Group Management Protocol, Version 2";

    }

    identity igmpv3 {
      base igmp-version;
      description "IGMPv3.";
      reference
        "RFC 3376: Internet Group Management Protocol, Version 3";

    }

    identity mld-version {
      description
        "Base identity for indicating the MLD version.";
    }

    identity mldv1 {
      base mld-version;
      description "MLDv1.";
      reference
        "RFC 2710: Multicast Listener Discovery (MLD) for IPv6";

    }

    identity mldv2 {
      base mld-version;
      description "MLDv2.";
      reference
        "RFC 3810: Multicast Listener Discovery Version 2 (MLDv2)
        	  for IPv6";

    }

    identity tf-type {
      description
        "Base identity for traffic types.";
    }

    identity multicast-traffic {
      base tf-type;
      description "Multicast traffic.";
    }

    identity broadcast-traffic {
      base tf-type;
      description "Broadcast traffic.";
    }

    identity unknown-unicast-traffic {
      base tf-type;
      description "Unknown unicast traffic.";
    }

    identity customer-application {
      description
        "Base identity for customer applications.";
    }

    identity web {
      base customer-application;
      description
        "Web applications (e.g., HTTP, HTTPS).";
    }

    identity mail {
      base customer-application;
      description "Mail application.";
    }

    identity file-transfer {
      base customer-application;
      description
        "File transfer application (e.g., FTP, Secure FTP (SFTP)).";
    }

    identity database {
      base customer-application;
      description "Database application.";
    }

    identity social {
      base customer-application;
      description
        "Social-network application.";
    }

    identity games {
      base customer-application;
      description "Gaming application.";
    }

    identity p2p {
      base customer-application;
      description
        "Peer-to-peer application.";
    }

    identity network-management {
      base customer-application;
      description
        "Management application (e.g., Telnet, syslog, SNMP).";
    }

    identity voice {
      base customer-application;
      description "Voice application.";
    }

    identity video {
      base customer-application;
      description
        "Video-conference application.";
    }

    identity embb {
      base customer-application;
      description
        "Enhanced Mobile Broadband (eMBB) application.
Note that eMBB applications demand network performance
with a wide variety of such characteristics as data rate,
latency, loss rate, reliability, and many other
parameters.";
    }

    identity urllc {
      base customer-application;
      description
        "Ultra-Reliable and Low Latency Communications (URLLC)
application.  Note that URLLC applications demand
network performance with a wide variety of such
characteristics as latency, reliability, and many other
parameters.";
    }

    identity mmtc {
      base customer-application;
      description
        "Massive Machine Type Communications (mMTC) application.
Note that mMTC applications demand network performance
with a wide variety of such characteristics as data rate,
latency, loss rate, reliability, and many other
parameters.";
    }

    identity bundling-type {
      description
        "The base identity for the bundling type.  It supports a
subset or all Customer Edge VLAN IDs (CE-VLAN IDs)
associated with an L2VPN service.";
    }

    identity multi-svc-bundling {
      base bundling-type;
      description
        "Multi-service bundling, i.e., multiple CE-VLAN IDs
can be associated with an L2VPN service at a site.";
    }

    identity one2one-bundling {
      base bundling-type;
      description
        "One-to-one service bundling, i.e., each L2VPN can
be associated with only one CE-VLAN ID at a site.";
    }

    identity all2one-bundling {
      base bundling-type;
      description
        "All-to-one bundling, i.e., all CE-VLAN IDs are mapped
to one L2VPN service.";
    }

    identity control-mode {
      description
        "Base identity for the type of control mode used with the
Layer 2 Control Protocol (L2CP).";
    }

    identity peer {
      base control-mode;
      description
        "'peer' mode, i.e., participate in the protocol towards
the CE.  Peering is common for the Link Aggregation Control
Protocol (LACP) and the Ethernet Local Management Interface
(E-LMI) and, occasionally, for the Link Layer Discovery
Protocol (LLDP).  For VPLSs and VPWSs, the subscriber can
also request that the peer service provider enable
spanning tree.";
    }

    identity tunnel {
      base control-mode;
      description
        "'tunnel' mode, i.e., pass to the egress or destination
site.  For Ethernet Private Lines (EPLs), the expectation
is that L2CP frames are tunneled.";
    }

    identity discard {
      base control-mode;
      description
        "'Discard' mode, i.e., discard the frame.";
    }

    identity neg-mode {
      description
        "Base identity for the type of negotiation mode.";
    }

    identity full-duplex {
      base neg-mode;
      description
        "Full-duplex negotiation mode.";
    }

    identity auto-neg {
      base neg-mode;
      description "Auto-negotiation mode.";
    }

    typedef vpn-id {
      type string;
      description
        "Defines an identifier that is used with a VPN module.
For example, this can be a service identifier, a node
identifier, etc.";
    }
  }  // module ietf-vpn-common