L2SM Working Group                                                B. Wen
Internet-Draft                                                   Comcast
Intended status: Standards Track                             G. Fioccola
Expires: May 2, 2017                                      Telecom Italia
                                                                  C. Xie
                                                           China Telecom
                                                                L. Jalil
                                                                 Verizon
                                                        October 29, 2016


              A YANG Data Model for L2VPN Service Delivery
                 draft-wen-l2sm-l2vpn-service-model-03

Abstract

   This document defines a YANG data model that can be used to configure
   a Layer 2 Provider Provisioned VPN service.

   This model is intended to be instantiated at management system to
   deliver the overall service.  This model is not a configuration model
   to be used directly on network elements, but provides an abstracted
   view of the Layer 2 VPN service configuration components.  It is up
   to a management system to take this as an input and use specific
   configurations models to configure the different network elements to
   deliver the service.  How configuration of network elements is done
   is out of scope of the document.

   The data model in this document includes support for point-to-point
   Virtual Private Wire Services (VPWS) and multipoint Virtual Private
   LAN services (VPLS) that use Pseudowires signaled using the Label
   Distribution Protocol (LDP) and the Border Gateway Protocol (BGP) as
   described in RFC4761 and RFC6624.

Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [RFC2119].

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute




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   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on May 2, 2017.

Copyright Notice

   Copyright (c) 2016 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   3
     1.2.  Tree diagram  . . . . . . . . . . . . . . . . . . . . . .   4
   2.  Definitions . . . . . . . . . . . . . . . . . . . . . . . . .   4
   3.  The Layer 2 VPN Service Model . . . . . . . . . . . . . . . .   5
     3.1.  Applicability of the Layer 2 VPN Service Model  . . . . .   6
     3.2.  Layer 2 VPN Service Types . . . . . . . . . . . . . . . .   6
     3.3.  Layer 2 VPN Service Network Topology  . . . . . . . . . .   7
     3.4.  Layer 2 VPN Ethernet Virtual Circuit Construct  . . . . .   8
   4.  Service Data Model Usage  . . . . . . . . . . . . . . . . . .  11
   5.  Design of the Data Model  . . . . . . . . . . . . . . . . . .  13
     5.1.  Overview of Main Components of the Model  . . . . . . . .  19
       5.1.1.  Customer Information  . . . . . . . . . . . . . . . .  19
       5.1.2.  VPN Service Overview  . . . . . . . . . . . . . . . .  19
         5.1.2.1.  Service Type  . . . . . . . . . . . . . . . . . .  19
         5.1.2.2.  ethernet-svc-type . . . . . . . . . . . . . . . .  20
         5.1.2.3.  Metro Network Partition . . . . . . . . . . . . .  20
         5.1.2.4.  vpn-signaling-option  . . . . . . . . . . . . . .  21
         5.1.2.5.  Load Balance Option . . . . . . . . . . . . . . .  23
         5.1.2.6.  SVLAN ID Ethernet Tag . . . . . . . . . . . . . .  24
         5.1.2.7.  CVLAN ID To EVC MAP . . . . . . . . . . . . . . .  24



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         5.1.2.8.  Service Level MAC Limit . . . . . . . . . . . . .  25
         5.1.2.9.  Service Protection  . . . . . . . . . . . . . . .  25
       5.1.3.  site  . . . . . . . . . . . . . . . . . . . . . . . .  26
         5.1.3.1.  Generic Site Objects  . . . . . . . . . . . . . .  26
   6.  Interaction with Other YANG Modules . . . . . . . . . . . . .  35
   7.  Service Model Usage Example . . . . . . . . . . . . . . . . .  36
   8.  YANG Module . . . . . . . . . . . . . . . . . . . . . . . . .  36
   9.  Security Considerations . . . . . . . . . . . . . . . . . . .  76
   10. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  76
   11. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  76
   12. References  . . . . . . . . . . . . . . . . . . . . . . . . .  77
     12.1.  Normative References . . . . . . . . . . . . . . . . . .  77
     12.2.  Informative References . . . . . . . . . . . . . . . . .  78
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  79

1.  Introduction

   This document defines a YANG data model for Layer 2 VPN (L2VPN)
   service configuration.  This model is intended to be instantiated at
   management system to allow a user (a customer or an application) to
   request the service.  This model is not a configuration model to be
   used directly on network elements, but provides an abstracted view of
   the L2VPN service configuration components.  It is up to a management
   system to take this as an input and use specific configurations
   models to configure the different network elements to deliver the
   service.  How configuration of network elements is done is out of
   scope of the document.

   The data model in this document includes support for point-to-point
   Virtual Private Wire Services (VPWS) and multipoint Virtual Private
   LAN services (VPLS) that use Pseudowires signaled using the Label
   Distribution Protocol (LDP) and the Border Gateway Protocol (BGP) as
   described in [RFC4761] and [RFC6624].

   Further discussion of the way that service are modelled in YANG and
   of the relationship between "customer service models" like the one
   described in this document and configuration models can be found in
   [I-D.wu-opsawg-service-model-explained].  Section 4 and Section 6
   also provide more information of how this service model could be used
   and how it fits into the overall modelling architecture.

1.1.  Terminology

   The following terms are defined in [RFC6241] and are not redefined
   here:

   o  client




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   o  configuration data

   o  server

   o  state data

   The following terms are defined in [RFC6020] and are not redefined
   here:

   o  augment

   o  data model

   o  data node

   The terminology for describing YANG data models is found in
   [RFC6020].

1.2.  Tree diagram

   A simplified graphical representation of the data model is presented
   in Section 5.

   The meaning of the symbols in these diagrams is as follows:

   o  Brackets "[" and "]" enclose list keys.

   o  Curly braces "{" and "}" contain names of optional features that
      make the corresponding node conditional.

   o  Abbreviations before data node names: "rw" means configuration
      (read-write), and "ro" state data (read-only).

   o  Symbols after data node names: "?" means an optional node and "*"
      denotes a "list" or "leaf-list".

   o  Parentheses enclose choice and case nodes, and case nodes are also
      marked with a colon (":").

   o  Ellipsis ("...") stands for contents of subtrees that are not
      shown.

2.  Definitions

   This document uses the following terms:






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   Service Provider (SP):  The organization (usually a commercial
      undertaking) responsible for operating the network that offers VPN
      services to clients and customers.

   Customer Edge (CE) Device:  Equipment that is dedicated to a
      particular customer and is directly connected to one or more PE
      devices via attachment circuits.  A CE is usually located at the
      customer premises, and is usually dedicated to a single VPN,
      although it may support multiple VPNs if each one has separate
      attachment circuits.  The CE devices can be routers, bridges,
      switches, or hosts.

   Provider Edge (PE) Device:  Equipment managed by the SP that can
      support multiple VPNs for different customers, and is directly
      connected to one or more CE devices via attachment circuits.  A PE
      is usually located at an SP point of presence (PoP) and is managed
      by the SP.

   Virtual Private LAN Service (VPLS):  A VPLS is a provider service
      that emulates the full functionality of a traditional Local Area
      Network (LAN).  A VPLS makes it possible to interconnect several
      LAN segments over a packet switched network (PSN) and makes the
      remote LAN segments behave as one single LAN.

   Virtual Private Wire Service (VPWS):  A VPWS is a point-to-point
      circuit (i.e., link) connecting two CE devices.  The link is
      established as a logical through a packet switched network.  The
      CE in the customer network is connected to a PE in the provider
      network via an Attachment Circuit (AC); the AC is either a
      physical or a logical circuit.  A VPWS differs from a VPLS in that
      the VPLS is point-to-multipoint, while the VPWS is point-to-point.
      In some implementations, a set of VPWSs is used to create a multi-
      site L2VPN network.

3.  The Layer 2 VPN Service Model

   A Layer 2 VPN service is a collection of sites that are authorized to
   exchange traffic between each other over a shared infrastructure of a
   common technology.  This Layer 2 VPN service model (L2SM) provides a
   common understanding of how the corresponding Layer 2 VPN service is
   to be deployed over the shared infrastructure.

   This document presents the L2SM using the YANG data modeling language
   [RFC6020] as a formal language that is both human-readable and
   parsable by software for use with protocols such as NETCONF [RFC6241]
   and RESTCONF [I-D.ietf-netconf-restconf].





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   This service model is limited to VPWS and VPLS based VPNs as
   described in [RFC4761] and [RFC6624].

3.1.  Applicability of the Layer 2 VPN Service Model

   The L2SM defined in this document applies to both point-to-point
   (E-Line) and multipoint-to-multipoint (E-LAN) carrier Ethernet
   services.

   Over the past decade, The MEF Forum (MEF) has published a series of
   technical specifications of Ethernet virtual circuit service
   attributes and implementation agreements between providers.  Many
   Ethernet VPN service providers worldwide have adopted these MEF
   standards and developed backoffice tools accordingly.

   Rather than introducing a new set of terminologies, the L2SM will
   align with existing MEF attributes when it's applicable.  Therefore,
   service providers can easily integrate any new application that
   leverages the L2SM data, Service Orchestrator for example, with
   existing BSS/OSS toolsets.  Service providers also have the option to
   generate L2SM data for current L2VPN customer circuits already
   deployed in the network.

3.2.  Layer 2 VPN Service Types

   A Layer 2 VPN circuit can be port-based; in which case any service
   frames received from subscriber within contractual bandwidth will be
   delivered to the corresponding remote site, regardless of customer
   VLAN value (C-tag) of the incoming frame.  The service frames can
   also be native Ethernet frames without C-tag.  In this scenario, only
   one Ethernet Virtual Circuit (EVC) is allowed on a single provider to
   subscriber link.

   Contrary to the above use case, incoming customer service frames may
   be split into multiple EVCs based on pre-arrangement between the
   service provider and customer.  Typically, C-tag of the incoming
   frames will serve as the service delimiter for EVC multiplexing over
   the same provider to subscriber interconnection.

   Combining the service-multiplexing attribute with point-to-point
   verses multipoint-to-multipoint connection type, a Layer 2 VPN
   circuit may fall under one of the following service types:

   o  E-Line services: Point-to-Point Layer 2 connections.

      EPL:  In its simplest form, a port-based Ethernet Private Line
         (EPL) service provides a high degree of transparency delivering
         all customer service frames between UNI-to-UNI interfaces using



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         All-to-One Bundling.  All unicast/broadcast/multicast packets
         are delivered unconditionally over the EVC.  No service
         multiplexing is allowed on an EPL UNI interface.

      EVPL:  On the other hand, Ethernet Virtual Private Line (EVPL)
         service supports multiplexing more than one Point-to-Point, or
         even other virtual private services, on the same UNI interface.
         Ingress service frames are conditionally transmitted through
         one of the EVCs based upon pre-agreed C-tag to EVC mapping.
         EVPL supports multiple C-tags to one EVC bundling.

   o  E-LAN services: Multipoint-to-Multipoint Layer 2 connections.

      EP-LAN:  Ethernet Private LAN Service (EP-LAN) transparently
         connects multiple subscriber sites together with All-to-One
         Bundling.  No service multiplexing is allowed on an EP-LAN UNI
         interface.

      EVP-LAN:  Some subscriber may desire more sophisticated control of
         data access between multiple sites.  Ethernet Virtual Private
         LAN Service (EVP-LAN) allows connecting to multiple EVCs from
         one or more of the UNI interfaces.  Services frame disposition
         is based on C-tag to EVC mapping.  EVP-LAN supports multiple
         C-tags to one EVC bundling.

3.3.  Layer 2 VPN Service Network Topology

   Figure 1depicts a typical service provider's physical network
   topology.  Most service providers have deployed an IP, MPLS, or
   Segment Routing (SR) multi-service core infrastructure.  Customer
   Edge (CE) devices are placed at customer premises as demarcation
   points to backhaul in profile service frames from the subscriber over
   the access network to the Provider Edge (PE) equipment.  The actual
   transport technology or physical topology between CE and PE is
   outside the scope of the L2SM model.
















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    ---     ----                                                ---
   |   |   |    |                                              |   |
   | C +---+ CE |                                              | C |
   |   |   |    |              ---------                       |   |
    ---     ----\             (         )                      /---
                 \  ----     (           )     ----     ----  /
                  \|    |   (             )   |    |   |    |/
                   | PE +---+ IP/MPLS/SR  +---+ PE +---+ CE |
                  /|    |   (  Network    )   |    |   |    |\
                 /  ----     (           )     ----     ----  \
    ---     ----/             (         )                      \---
   |   |   |    |              ----+----                       |   |
   | C +---+ CE |                  |                           | C |
   |   |   |    |                --+--                         |   |
    ---     ----                | PE  |                         ---
                                 --+--
                                   |
                                 --+--
                                | CE  |
                                 --+--
                                   |
                                 --+--
                                |  C  |
                                 -----


    Figure 1: Reference Network for the Use of the L2VPN Service Model

   From the subscriber perspective, however, all the edge networks
   devices are connected over a simulated LAN environment as shown in
   Figure 2.  Broadcast and multicast packets are sent to all
   participants in the same bridge domain.


                     C---+----+---+---C
                         |    |   |
                         |    |   |
                         |    |   |
                     C---+    C   +---C


                   Figure 2: Customer View of the L2VPN

3.4.  Layer 2 VPN Ethernet Virtual Circuit Construct

   The base model of EVC is shown in Figure 3.





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   Subscriber edge network device (C) connects to the service provider's
   CE equipment.  The link between C and CE devices is referred as User
   Network Interface (UNI).  For clarification, this is called UNI-C on
   subscriber side and UNI-N on provider side.

   The service provider is obligated to deliver the original service
   frame across the network to the remote UNI-C.  All Ethernet and IP
   header information, including (but not limit to) source and
   destination MAC addresses, EtherType, VLAN (C-tag), Class-of-Service
   marking (802.1p or DSCP), etc.

   In coming service frames are first examined at UNI-N based on C-tag,
   Class-of-Services identifier, EtherType value.  Conforming packets
   are then metered against the contractual service bandwidth.  In-
   profile packets will be delivered to the remote UNI via the Ethernet
   Virtual Circuit (EVC), which spans between UNI-N to UNI-N.

   When both CEs are located in the same provider's network, a single
   operator maintains the EVC.  In this case, the EVC consists only one
   Operator Virtual Circuit (OVC).

   Typically, the CE device at customer premises is a layer 2 Ethernet
   switch or NID.  Service provider may choose to impose an outer VLAN
   tag (S-tag) into the received subscriber traffic following 802.1ad
   Q-in-Q standard, especially when Layer 2 aggregation devices exist
   between CE and PE.

   The uplink from CE to PE is referred as Internal Network-to-Network
   Interface (I-NNI).  When 802.1ad Q-in-Q is implemented, Ethernet
   frames from CE to PE are double tagged with both provider and
   subscriber VLANs (S-tag, C-tag).

   Most service providers have deployed MPLS or SR multi-service core
   infrastructure.  Ingress service frames will be mapped to either
   Ethernet Pseudowire (PWE) or VxLAN tunnel PE-to-PE.  The details of
   these tunneling mechanism are at the provider's discretion and not
   part of the L2SM.

   Service provider may also choose Seamless MPLS approach to expand the
   PWE or VxLAN tunnel between UNI-N to UNI-N.

   Service provider may leverage multi-protocol BGP to auto discover and
   signal the PWE or VxLAN tunnel end points.








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                                   EVC
             :<-------------------------------------------->:
             :                                              :
             :                                              :
             :                OVC (Optional)                :
             :<-------------------------------------------->:
             :                                              :
             :                                              :
             :                  PW / VXLAN                  :
             :        :<-------------------------->:        :
             :        :                            :        :
             :        :                            :        :
             :        :          --------          :        :
             :        :         (        )         :        :
     ---     ----     ----     (          )     ----     ----     ---
    |   |   |    |   |    |   (            )   |    |   |    |   |   |
    | C +---+ CE +---+ PE +---+ IP/MPLS/SR +---+ PE +---+ CE +---+ C |
    |   |   |    |   |    |   (  Network   )   |    |   |    |   |   |
     ---     ----     ----     (          )     ----     ----     ---
      ^      ^        :         (        )         :        :
      :      :        :          --------          :        :
    UNI-C  UNI-N      :                            :        :
             :        :                            :        :
             :<------>:<-------------------------->:<------>:
              802.1ad      IP/MPLS/SR Domain        802.1ad
              q-in-q                                q-in-q


        Figure 3: Architectural Model for EVC over a Single Network

   Nevertheless, the remote site may be outside of the provider's
   service territory.  In this case, the provider may partner with the
   operator of another metro network to provider service to the off-net
   location as shown in Figure 4.

   The first provider owns the customer relationship, thus the end-to-
   end EVC.  The EVC is comprised of two or more OVCs.  Partially of the
   EVC is an OVC from local UNI-C to the inter-provider interface.  The
   provider will purchase an Ethernet Access (E-Access) OVC from the
   second operator to deliver packet to the remote UNI-C.

   The inter-connect between the two operators edge gateway (EG) devices
   is defined as the External Network-to-Network Interface (E-NNI).








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                            EVC
         :<---------------------------------------------------->:
         :                                                      :
         :                                                      :
         :       OVC (Optional)                                 :
         :<----------------------->:                            :
         :                         :                            :
         :                         :                            :
         :           PW / VXLAN    :                            :
         :    :<------------------>:                            :
         :    :                    :                            :
         :    :                    :                            :
         :    :      -----         :            -----           :
         :    :     (     )        :           (     )          :
     -   --   --   (  IP/  )   ----    ----   (  IP/  )   --   --   -
    |C+-+CE+-+PE+--+ MPLS/ +--+Edge+--+Edge+--+ MPLS/ +--+PE+-+CE+-+C|
     -   --   --   (  SR   )  |G/W |  |G/W |  (  SR   )   --   --   -
     ^    ^   :     (     )    ----    ----    (     )              ^
     :    :   :      -----         ^   ^        -----               :
    UNI  UNI  :                 ENNI   ENNI                         :
     C    N   :                    :   :                            :
          :   :                    :   :                       Remote
          :<->:<------------------>:<->:                     Customer
         802.1ad    IP/MPLS/SR    802.1ad                        Site
          q-in-q      Domain       q-in-q


       Figure 4: Architectural Model for EVC over Multiple Networks

4.  Service Data Model Usage

   The L2VPN service model provides an abstracted interface to request,
   configure and manage the components of a L2VPN service.  The model is
   used by a customer who purchases connectivity and other services from
   an SP to communicate with that SP.

   A typical usage is for this model to be an input for an orchestration
   layer that is responsible for translating it into configuration
   commands for the network elements that deliver/enable the service.
   The network elements may be routers, but also servers (like AAA)
   necessary within the network.

   The configuration of network elements may be done using the Command
   Line Interface (CLI), or any other configuration (or "southbound")
   interface such as NETCONF [RFC6241] in combination with device-
   specific and protocol-specific YANG models.





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   This way of using the service model is illustrated in Figure 5 and
   described in more detail in [I-D.wu-opsawg-service-model-explained].
   The usage of this service model is not limited to this example: it
   can be used by any component of the management system, but not
   directly by network elements.

   The usage and structure of this model should be compared to the Layer
   3 VPN service model defined in [I-D.ietf-l3sm-l3vpn-service-model].


          ----------------------------
         | Customer Service Requester |
          ----------------------------
              |
      L2VPN   |
      Service |
      Model   |
              |
            -----------------------
           | Service Orchestration |
            -----------------------
              |
              |     Service             +-------------+
              |     Delivery    +------>| Application |
              |     Model       |       |   BSS/OSS   |
              |                 V       +-------------+
            -----------------------
           | Network Orchestration |
            -----------------------
              |            |
      +----------------+   |
      | Config manager |   |
      +----------------+   |  Device
              |            |  Models
              |            |
   --------------------------------------------
                     Network


     Figure 5: Reference Architecture for the Use of the L2VPN Service
                                   Model

   Additionally, this data model can be compared with the service
   delivery models described in [I-D.ietf-bess-l2vpn-yang] and
   [I-D.ietf-bess-evpn-yang] as discussed in Section 6.






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5.  Design of the Data Model

   The YANG module is divided in three main containers : customer-info,
   vpn-services, and sites.

   The customer-info defines global parameters for a specific customer.

   The vpn-svc container under vpn-services defines global parameters
   for the VPN service for a specific customer.

   A site is composed of at least one uni-site or one enni-site.

   Authorization of traffic exchange is done through what we call a VPN
   policy or VPN topology defining routing exchange rules between sites.

   The figure below describe the overall structure of the YANG module:


   module: ietf-l2vpn-svc
   +--rw l2vpn-svc
      +--rw customer-info
      |  +--rw customer-info* [customer-account-number customer-name]
      |     +--rw customer-account-number           uint32
      |     +--rw customer-name                     string
      |     +--rw customer-operation-center
      |        +--rw customer-noc-street-address?   string
      |        +--rw customer-noc-phone-number
      |           +--rw main-phone-num?             uint32
      |           +--rw extension-options?          uint32
      +--rw vpn-services
      |  +--rw vpn-svc* [svc-id]
      |     +--rw svc-id                  string
      |     +--rw svc-type
      |     |  +--rw evc
      |     |  |  +--rw evc-id?           boolean
      |     |  |  +--ro number-of-pe?     uint32
      |     |  |  +--ro number-of-site?   uint32
      |     |  +--rw ovc
      |     |     +--rw on-net-ovc-id?   boolean
      |     |     +--rw off-net-ov-id?   boolean
      |     +--rw ethernet-svc-type
      |     |  +--rw (ethernet-svc-type)?
      |     |     +--:(e-line)
      |     |     |  +--rw epl?           boolean
      |     |     |  +--rw evpl?          boolean
      |     |     +--:(e-lan)
      |     |     |  +--rw ep-lan?        boolean
      |     |     |  +--rw evp-lan?       boolean



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      |     |     +--:(e-access)
      |     |        +--rw access-epl?    boolean
      |     |        +--rw access-evpl?   boolean
      |     +--rw metro-network-id
      |     |  +--rw inter-mkt-service?   boolean
      |     |  +--rw intra-mkt* [metro-mkt-id mkt-name]
      |     |     +--rw metro-mkt-id      uint32
      |     |     +--rw mkt-name          string
      |     +--rw signaling-option
      |     |  +--rw signaling-option* [name type]
      |     |     +--rw name              string
      |     |     +--rw type              identityref
      |     |     +--rw mp-bgp-l2vpn
      |     |     |  +--rw vpn-id?        string
      |     |     |  +--rw type?          identityref
      |     |     +--rw mp-bgp-evpn
      |     |     |  +--rw vpn-id?        string
      |     |     |  +--rw type?          identityref
      |     |     +--rw t-ldp-pwe
      |     |     |  +--rw PE-EG-list* [service-ip-lo-addr vc-id]
      |     |     |     +--rw service-ip-lo-addr    inet:ip-address
      |     |     |     +--rw vc-id                 string
      |     |     +--rw pwe-encapsulation-type
      |     |     |  +--rw ethernet?      boolean
      |     |     |  +--rw vlan?          boolean
      |     |     +--rw pwe-mtu
      |     |     |  +--rw allow-mtu-mismatch?      boolean
      |     |     +--rw control-word
      |     +--rw load-balance-options
      |     |  +--rw fat-pw?                 boolean
      |     |  +--rw entropy-label?          boolean
      |     |  +--rw vxlan-source-port?      string
      |     +--rw svlan-id-ethernet-tag?     string
      |     +--rw cvlan-id-to-evc-map?       string
      |     +--rw service-level-mac-limit?   string
      |     +--rw service-protection
      |     |  +--rw protection-model
      |     |  +--rw peer-evc-id
      |     +--rw sla-targets
      +--rw sites
         +--rw site* [site-id site-type]
            +--rw site-id                       string
            +--rw site-type                     identityref
            +--rw device
            |  +--rw devices* [device-id]
            |     +--rw device-id               string
            |     +--rw site-name?              string
            |     +--rw address?                inet:ip-address



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            |     +--rw management-transport?   identityref
            +--rw managemnt
            |  +--rw type?   identityref
            +--rw location
            |  +--rw address?        string
            |  +--rw zip-code?       string
            |  +--rw state?          string
            |  +--rw city?           string
            |  +--rw country-code?   string
            +--rw site-diversity {site-diversity}?
            |  +--rw groups
            |     +--rw group* [group-id]
            |        +--rw group-id  string
            +--rw security
            +--rw signaling-option {signaling-option}?
            |  +--rw signaling-option* [name type]
            |     +--rw name         string
            |     +--rw type         identityref
            |     +--rw mp-bgp-l2vpn
            |     |  +--rw vpn-id?   string
            |     |  +--rw type?     identityref
            |     +--rw mp-bgp-evpn
            |     |  +--rw vpn-id?   string
            |     |  +--rw type?     identityref
            |     +--rw t-ldp-pwe
            |     |  +--rw PE-EG-list* [service-ip-lo-addr vc-id]
            |     |     +--rw service-ip-lo-addr    inet:ip-address
            |     |     +--rw vc-id                 string
            |     +--rw pwe-encapsulation-type
            |     |  +--rw ethernet? boolean
            |     |  +--rw vlan?     boolean
            |     +--rw pwe-mtu
            |     |  +--rw allow-mtu-mismatch?      boolean
            |     +--rw control-word
            +--rw load-balance-options
            |  +--rw fat-pw?              boolean
            |  +--rw entropy-label?       boolean
            |  +--rw vxlan-source-port?   string
            +--rw ports
               +--rw port* [id]
                  +--rw id                      string
                  +--rw remote-carrier-name?    string
                  +--rw groups
                  |  +--rw fate-sharing-group-size?  uint16
                  |  +--rw group* [group-id]
                  |     +--rw group-id               string
                  +--rw bearer
                  |  +--rw phy-interface



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                  |  |  +--rw port-number?           uint32
                  |  |  +--rw port-speed?            uint32
                  |  |  +--rw auto-neg?              string
                  |  |  +--rw phy-mtu?               uint32
                  |  |  +--rw flow-control?          string
                  |  |  +--rw encapsulation-type?    enumeration
                  |  |  +--rw ethertype?             string
                  |  |  +--rw lldp?                  boolean
                  |  |  +--rw oam-802.3AH-link {oam-3ah}?
                  |  |  |  +--rw enable?   boolean
                  |  |  +--rw uni-loop-prevention?   boolean
                  |  +--rw LAG-interface
                  |  |  +--rw LAG-interface* [LAG-interface-number]
                  |  |     +--rw LAG-interface-number      uint32
                  |  |     +--rw LACP
                  |  |        +--rw LACP-state?            identityref
                  |  |        +--rw LACP-mode?             identityref
                  |  |        +--rw LACP-speed?            identityref
                  |  |        +--rw mini-link?             uint32
                  |  |        +--rw system-priority?       uint16
                  |  |        +--rw Micro-BFD {Micro-BFD}?
                  |  |        |  +--rw Micro-BFD-on-off?   enumeration
                  |  |        |  +--rw bfd-interval?       uint32
                  |  |        |  +--rw bfd-hold-timer?     uint32
                  |  |        +--rw bfd {bfd}?
                  |  |        |  +--rw bfd-enabled?        boolean
                  |  |        |  +--rw (holdtime)?
                  |  |        |     +--:(profile)
                  |  |        |     |  +--rw profile-name? string
                  |  |        |     +--:(fixed)
                  |  |        |        +--rw fixed-value?  uint32
                  |  |        +--rw Member-link-list
                  |  |        |  +--rw member-link* [name]
                  |  |        |     +--rw name             string
                  |  |        |     +--rw port-speed?      uint32
                  |  |        |     +--rw auto-neg?        string
                  |  |        |     +--rw mtu?             uint32
                  |  |        |     +--rw oam-802.3AH-link {oam-3ah}?
                  |  |        |        +--rw enable?       boolean
                  |  |        +--rw flow-control?          string
                  |  |        +--rw encapsulation-type?    enumeration
                  |  |        +--rw ethertype?             string
                  |  |        +--rw lldp?                  boolean
                  |  +--rw interface-description?          string
                  |  +--rw sub-if-id?                      uint32
                  +--rw ethernet-connection
                  |  +--rw vlan
                  |     +--rw svlan-id-ethernet-tag?       string



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                  +--rw evc-mtu?                           uint32
                  +--rw mac-addr-limit
                  |  +--rw exceeding-option?               uint32
                  +--rw multihoming
                  |  +--rw multihoming* [ESI]
                  |     +--rw ESI                          string
                  |     +--rw (redundancy-mode)?
                  |        +--:(single-active)
                  |        |  +--rw single-active?         boolean
                  |        +--:(all-active)
                  |           +--rw all-active?            boolean
                  +--rw L2CP-control
                  |  +--rw stp-rstp-mstp?             control-mode
                  |  +--rw pause?                     control-mode
                  |  +--rw lacp-lamp?                 control-mode
                  |  +--rw link-oam?                  control-mode
                  |  +--rw esmc?                      control-mode
                  |  +--rw l2cp-802.1x?               control-mode
                  |  +--rw e-lmi?                     control-mode
                  |  +--rw lldp?                      boolean
                  |  +--rw ptp-peer-delay?            control-mode
                  |  +--rw garp-mrp?                  control-mode
                  |  +--rw provider-bridge-group?     yang:mac-address
                  |  +--rw provider-bridge-mvrp?      yang:mac-address
                  +--rw service
                  |  +--rw svlan-id-ethernet-tag?     string
                  |  +--rw cvlan-id-to-evc-map?       string
                  |  +--rw service-level-mac-limit?   string
                  |  +--rw service-level
                  |     +--rw cos-identifier?                identityref
                  |     +--rw color-identifier?              identityref
                  |     +--rw ingress-bw-profile-per-evc?    string
                  |     +--rw ingress-bw-profile-per-cos-id? string
                  |     +--rw egress-bw-profile-per-evc?     string
                  |     +--rw egress-bw-profile-per-cos-id?  string
                  |     +--rw byte-offset?                   uint16
                  |     +--rw policing?                      identityref
                  |     +--rw performance-tier-option?       identityref
                  |     +--rw COS?                           uint32
                  +--rw B-U-M-strom-control
                  |  +--rw BUM-overall-rate?         uint32
                  |  +--rw BUM-rate-per-type* [type]
                  |     +--rw type                   identityref
                  |     +--rw rate?                  uint32
                  +--rw mac-loop-prevention
                  |  +--rw frequency?                uint32
                  |  +--rw protection-type?          identityref
                  |  +--rw number-retries?           uint32



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                  +--rw Ethernet-Service-OAM
                  |  +--rw MD-name?                  string
                  |  +--rw MD-level?                 uint8
                  |  +--rw cfm-802.1-ag
                  |  |  +--rw n2-uni-c* [MAID]
                  |  |  |  +--rw MAID                     string
                  |  |  |  +--rw mep-id?                  uint32
                  |  |  |  +--rw mep-level?               uint32
                  |  |  |  +--rw mep-up-down?             enumeration
                  |  |  |  +--rw remote-mep-id?           uint32
                  |  |  |  +--rw cos-for-cfm-pdus?        uint32
                  |  |  |  +--rw ccm-interval?            uint32
                  |  |  |  +--rw ccm-holdtime?            uint32
                  |  |  |  +--rw alarm-priority-defect?   identityref
                  |  |  |  +--rw ccm-p-bits-pri?       ccm-priority-type
                  |  |  +--rw n2-uni-n* [MAID]
                  |  |     +--rw MAID                     string
                  |  |     +--rw mep-id?                  uint32
                  |  |     +--rw mep-level?               uint32
                  |  |     +--rw mep-up-down?             enumeration
                  |  |     +--rw remote-mep-id?           uint32
                  |  |     +--rw cos-for-cfm-pdus?        uint32
                  |  |     +--rw ccm-interval?            uint32
                  |  |     +--rw ccm-holdtime?            uint32
                  |  |     +--rw alarm-priority-defect?   identityref
                  |  |     +--rw ccm-p-bits-pri?       ccm-priority-type
                  |  +--rw y-1731* [MAID]
                  |     +--rw MAID                           string
                  |     +--rw mep-id?                        uint32
                  |     +--rw type?                          identityref
                  |     +--rw remote-mep-id?                 uint32
                  |     +--rw message-period?                uint32
                  |     +--rw measurement-interval?          uint32
                  |     +--rw cos?                           uint32
                  |     +--rw loss-measurement?              boolean
                  |     +--rw synthethic-loss-measurement?   boolean
                  |     +--rw delay-measurement
                  |     |  +--rw enable-dm?   boolean
                  |     |  +--rw two-way?     boolean
                  |     +--rw frame-size?                    uint32
                  |     +--rw session-type?                  enumeration
                  +--rw security


                                 Figure 6






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5.1.  Overview of Main Components of the Model

   The L2SM model is structured in a way that allows the provider to
   list multiple circuits of various service types for the same
   subscriber.

5.1.1.  Customer Information

   The "customer-info" container contains essential information to
   identify the subscriber.

   "customer-account-number" is an internal alphanumerical number
   assigned by the service provider to identify the subscriber.  It MUST
   be unique within the service provider?s OSS/BSS system.  The actual
   format depends on the system tool the provider uses.  "customer-name"
   is in more readable form.

   Subscriber operation center and main contact number are also listed
   here for reference purpose.

5.1.2.  VPN Service Overview

   The "svc-type" container contains two optional leaves: one for EVC
   (Ethernet Virtual Connection) and the other one for OVC (Operator
   Virtual Connection).  These two parameters are not mutually
   exclusive.  Depending on the service-type, a Layer 2 VPN service may
   be identified by EVC-ID, OVC-ID, or both.

   E-Line and E-LAN provider shall have EVC-ID assigned to the UNI-to-
   UNI circuit.  If the service has remote UNIs in off-net partner's
   network, there will be one OVC-ID for the on-net segment between
   local UNI to the E-NNI interconnect, and one OVC-ID for each off-net
   segment from E-NNI to the remote UNI.  E-Access, on the other hand,
   is OVC-based service.  The E-Access service provider will assign OVC-
   ID for the circuit between UNI to E-NNI.

   The "svc-type" container can be augmented in the future to support
   other new technologies.  Note that the "svc-id" should be
   corresponding to the "svc-type".

5.1.2.1.  Service Type

   The "svc-type" container contains two cases, one for EVC (Ethernet
   Virtual Connection), the other for OVC (Operator Virtual Connection).
   It can be used to indicate the type of service pipe type.  The model
   user also can augment the "svc-type" container with other cases to
   support future technologies.  Notes that the "svc-id" should be
   corresponding to the "svc-type".



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5.1.2.1.1.  EVC

   The "evc"case contains an "evc-id" leaf with boolean type.  The "evc-
   id" leaf will be marked TRUE for E-Line and E-LAN service types.  And
   the "svc-id" will be associated with the "evc-id".  Only one "evc-id"
   is allowed for each "svc-id".

   The EVC ID is intended to be a structured string.  Each service
   provider can decide the nomenclature in its network.  For example,
   many carriers in North American have implemented the COMMON LANGUAGE?
   Special Service Circuit Codes (CLCI S/S Codes) - Serial Number
   Format, which is defined in defined in ANSI ATIS-0300097.

5.1.2.1.2.  OVC

   The "ovc" case contains two boolean subcases: "on-net-ovc" and "off-
   net-ovc".

   For E-Access or services with off-net UNIs, the "on-net-ovc" leaf
   MUST be marked TRUE.  And the "on-net-ovc-id" will be specified.

   In case of E-Access, the "svc-id" will be associated with the "on-
   net-ovc-id".  Only one "on-net-ovc-id" is allowed for each "svc-id".

   If the service is E-Line or E-LAN with remote UNIs, there will be
   one, and only one, "on-net-ovc-id" and a list of "off-net-ovc-id"s
   for the remote UNIs.  However, the "svc-id" is still associated with
   the "evc-id".  Only one "evc-id" is allowed for each "svc-id".  New
   ovc type could be added by augmentation.

5.1.2.2.  ethernet-svc-type

   The "ethernet-svc-type" group contains all supported Ethernet service
   types.  One, and only one, "ethernet-svc-type" must be selected for
   each "svc-id".

   The current supported Ethernet service types are listed in
   Section 3.2.  New service types can be added in the future.

5.1.2.3.  Metro Network Partition

   Some service providers may divide their network into multiple
   administrative domains.  And a Layer 2 VPN service may span across
   more than one metro network of the same service provider.  The
   optional "metro-network-id" container is intended be used by these
   multi-domain providers to differentiate intra-market versus inter-
   market services.




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   When the "inter-mkt-service" leaf is marked TRUE, multiple associated
   "metro-mkt-id"s will be listed.  Otherwise, the service is intra-
   domain and only one "metro-mkt-id" is allowed.

5.1.2.4.  vpn-signaling-option

   The "signaling-option" container captures service-wide attributes of
   the L2VPN instance.

   Although topology discovery or network device configurations is
   purposely out-scoped from the L2SM model, certain VPN parameters are
   listed here nevertheless.  The information here can then be passed to
   other elements in the whole automation eco-system, such as the
   configuration engine, which will handle the actual service
   provisioning function.

   The "signaling-option" list uses "name" and "type" combination as the
   key.  The "name" leaf is a free-form string of the VPN instance name.
   The "type" leaf is for the signaling protocol: BGP-L2VPN, BGP-EVPN,
   or T-LDP.

5.1.2.4.1.  BGP L2VPN

   [RFC4761] and [RFC6624] describe the mechanism to auto-discover L2VPN
   VPLS/VPWS end points (CE-ID or VE-ID) and signal the label base and
   offset at the same time to allow remote PE to derive the VPN label to
   be used when sending packets to the advertising router.

   Due to the auto-discovery natural, PEs that have at least one
   attachment circuit associated with a particular VPN service do not
   need to be specified explicitly.

   In the L2SM model, only the target community (or communities) will be
   listed at the service level.

   The "type" leaf under "mp-bgp-l2vpn" is an identityref to specify
   "vpws" or "vpls" sub-types.

5.1.2.4.2.  BGP EVPN

   Defined in [RFC7432], EVPN is a new promising L2VPN technology based
   upon BGP MAC routing.  It's considered the next generation L2VPN
   solution that provides similar functionality of BGP VPWS/VPLS with
   improvement around redundancy, multicast optimization, provisioning
   and simplicity.






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   Due to the auto-discovery natural, PEs that have at least one
   attachment circuit associated with a particular VPN service do not
   need to be specified explicitly.

   In the L2SM model, only the target community (or communities) will be
   listed at the service level.

   The "type" leaf under "mp-bgp-evpn" is an identityref to specify
   "vpws" or "vpls" sub-types.

5.1.2.4.3.  LDP Pseudowires

   [RFC4762] specified the method of using targeted LDP sessions between
   PEs to exchange VC label information.  This requires a manually
   define a full mesh of targeted LDP sessions between all PEs.

   As multiple attachment circuits may terminate on a single PE, this
   PE-to-PE mesh is not a per site attribute.  All PEs related to the
   L2VPN service will be listed in the "t-ldp-pwe" with associated "vc-
   id".

5.1.2.4.4.  PWE Encapsulation Type

   Based on [RFC4448], there are two types of Ethernet services: "Port-
   to-Port Ethernet PW emulation" and "Vlan-to-Vlan Ethernet PW
   emulation", commonly referred to as Type 5 and Type 4 respectively.
   This concept applies to both BGP L2VPN VPWS/VPLS and T-LDP signaled
   PWE implementations.

   The "pwe-encapsulation-type" container contains two Boolean type
   leaves: "ethernet" and "ethernet-vlan", only one should be marked
   TRUE if "signaling-option" is "mp-bgp-l2vpn" or "t-ldp-pwe".

5.1.2.4.5.  PWE MTU

   During the signaling process of BGP-L2VPN or T-LDP pseudowire, the
   pwe-mtu value is exchanged and must match on both ends.  By default,
   the pwe-mtu is derived from physical interface MTU of the attachment
   circuit minus the EoMPLS transport header.  In some cases, however,
   the physical interface on both ends of the circuits may not have
   identical MTU settings.  For example, due to 802.1ad q-in-q
   operation, I-NNI interface will need extra four bytes to accommodate
   the S-tag.  The inter-carrier E-NNI link may also have a different
   MTU size then the internal network interfaces.

   [RFC4448] requires same MTU size on physical interface on both end of
   the pseudowire.  In actual implementations, many router vendors have




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   provided the knob to explicitly specify the pwe-mtu, which can then
   be decoupled from the physical interface MTU.

   When there's a mismatch between the physical interface MTU and
   configured pwe-mtu, "allow-mtu-mismatch" knob is also required in
   many cases.

   The optional "pwe-mtu" container is for this purpose.

5.1.2.4.6.  Control Word

   A control word is an optional 4-byte field located between the MPLS
   label stack and the Layer 2 payload in the pseudowire packet.  It
   plays a vital role in Any Transport over MPLS (AToM).  The 32-bit
   field carries generic and Layer 2 payload-specific information,
   including a C-bit which indicates whether the control word will
   present in the Ethernet over MPLS (EoMPLS) packets.  If the C-bit is
   set to 1, the advertising PE expects the control word to be present
   in every pseudowire packet on the pseudowire that is being signaled.
   If the C-bit is set to 0, no control word is expected to be present.

   Whether to include control word in the pseudowire packets MUST match
   on PEs at both ends of the pseudowire and it's non-negotiable during
   the signaling process.

   Control-word applies to both BGP L2VPN VPWS/VPLS and T-LDP signaled
   PWE implementations.  It is a routing-instance level configuration in
   many cases.

   The optional "control-word" leaf is a Boolean field in the L2SM model
   for the provider to explicitly specify whether control-word will be
   signaled for the service instance.

5.1.2.5.  Load Balance Option

   As the subscribers start to deploy more 10G or 100G Ethernet
   equipment in their network, the demand for high bandwidth Ethernet
   services increases.  Along with the great revenue opportunities,
   these high bandwidth service requests also pose challenges on
   capacity planning and service delivery in the provider's network.
   Especially when the contractual bandwidth is at, or close to, the
   speed of physical link of the service provider's core network.
   Because of the encapsulation overhead, the provider can not deliver
   the throughput in the service level agreement over a single link.
   Although there may be bundled Nx10G or Nx100G aggregation links
   between core network elements, or Equal Cost Multiple Paths (ECMP) in
   the network, an EoMPLS PWE or VxLAN circuit is considered a single




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   flow to a router or switch which uses the five tuples in the hashing
   algorithm.

   Without burdening the core routers with additional processing of deep
   inspection into the payload, the service provider now have the option
   of inserting flow or entropy label into the EoMPLS frames, or using
   different source UDP ports in case of VxLAN/EVPN, at ingress PE to
   facility load-balancing on the subsequent nodes along the path.  The
   ingress PE is in a unique position to see the actual unencapsulated
   service frames and identify data flows based on the original Ethernet
   and IP header.

   On the other hand, not all Layer 2 Ethernet VPNs is suited for load-
   balancing across diverse ECMP paths.  For example, a Layer 2 Ethernet
   service transported over a single RSVP signaled LSP will not take
   multiple ECMP paths.  Or if the subscriber is concerned about
   latency/jitter then diverse path load-balance can be undesirable.

   The optional "load-balance-option" container is intended to capture
   the load-balance agreement between the subscriber and provider.  If
   the "load-balance" Boolean leaf is marked TRUE, then one of the
   following load-balance methods can be selected: "fat-pw", "entropy-
   label", or "vxland-source-udp-port".

5.1.2.6.  SVLAN ID Ethernet Tag

   Service providers have the option of inserting an outer VLAN tag (the
   S-tag) into the service frames from the subscriber to improve service
   scalability and customer VLAN transparency.

   Ideally, all external interfaces (UNI and E-NNI) associated with a
   given service will have the same S-tag assigned.  However, this may
   not always be the case.  Traffic with all attachments using different
   S-tags will need to be "normalized" to a single service S-tag.  (One
   example of this is a multipoint service involves multiple off-net
   OVCs terminating on the same E-NNI interface.  Each of these off-net
   OVCs will have a distinct S-tag, which can be different from the
   S-tag used in the on-net part of the service.)

   The purpose of the optional "svlan-id-ethernet-tag" leaf is to
   identify the service-wide "normalized S-tag".

5.1.2.7.  CVLAN ID To EVC MAP

   When more than one services are multiplexed on the same interface,
   ingress service frames are conditionally transmitted through one of
   the EVC/OVCs based upon pre-arranged customer VLAN to EVC mapping.
   Multiple customer VLANs can be bundled across the same EVC.



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   "cvlan-id-to-evc-map", when applicable, contains the list of customer
   vlans to the service mapping in a free-form format.  In most cases,
   this will be the VLAN access-list for the inner 802.1q tags (the
   C-tag).

5.1.2.8.  Service Level MAC Limit

   When multiple services are provided on the same network element, MAC
   address table, and RIB space for MAC-routes in case of EVPN, are
   shared common resource.  Service providers may impose a maximum
   number of MAC learned from the subscriber for a single service
   instance, and specify the action when the upper limit is violated:
   drop the packet, flood the packet, or simply send a warning log
   message.

   For point-to-point services, if MAC learning is disabled then MAC
   limit is not necessary in this kind of implementation.

   The optional "service-level-mac-limit" container contains the
   subscriber MAC address limit and exceeding action information.

5.1.2.9.  Service Protection

   Sometimes the subscriber may desire end-to-end protection at the
   service level for applications with high availability requirements.
   There are two protection schemes to offer redundant services:

   o  1+1 protection: In this scheme, the primary EVC or OVC will be
      protected by a backup EVC or OVC, typically meet certain
      diversified path/fiber/site/node criteria.  Both primary and
      protection circuits are provisioning to be in forwarding state.
      Subscriber may choose to send the same service frames across both
      circuits simultaneously.

   o  1:1 protection: In this scheme, a backup circuit can be
      provisioning to the primary circuits.  Depending on the
      implementation agreement, the protection circuits may either
      always be in forwarding state, or only become active when
      detecting a faulty state or the primary circuit.

   The optional "service-protection" container hereby is to capture the
   desired service protection agreement between subscriber and provider.

   An "peer-evc-id" should be specified when the "protection-model" has
   value.






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5.1.3.  site

   The "site" container is intended for the provider to store
   information of detailed implementation arrangement with either the
   subscriber or peer operators at each inter-connect location.

   We are restricting the L2SM to exterior interfaces only.  All
   internal interfaces or the underlying topology is outside the scope
   of L2SM.

   There are possibly two types of external facing connections
   associated with an Ethernet VPN service:

   o  UNI site: where a customer edge device connects to one or more VPN
      services.

   o  E-NNI site: where two Ethernet service providers inter-connect
      with each other.

   Most of the attributes of a site are common to the two typs of site
   and so are presented just once.  Divergences, that is, attributes
   that are specific to the type of site, are captured in type-dependent
   containers.

   For each site, there are sub-containers to maintain physical link
   attributes, service frame and Layer 2 control protocol frame
   disposition, Ethernet service OAM attributes, and service bandwidth
   profile and priority level agreement.

5.1.3.1.  Generic Site Objects

   Typically, the following characteristics of a site interface handoff
   need to be documented as part of the service design:

   Unique identifier (site-id) :  An arbitrary string to uniquely
      identify the site within the overall network infrastructure.  The
      format of site-id is determined by the local administration of the
      VPN service.

   Site Type (site-type) :  TBD.

   Device (device) :  TBD.

   Management (management) :  Defines the model of management of the
      site, for example: type, management-transport, address.

   Location (location) :  The site location information to allow easy
      retrieval on nearest available resources.



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   Site diversity (site-diversity) :  Presents some parameters to
      support site diversity.

   Site security (security) :  TBD.

   Site signaling (signaling-options) :  TBD.

   Load balancing (load-balance-options) :  TBD.

   Ports (ports) :  Defines the list of ports to the sites and their
      properties.

5.1.3.1.1.  Site ID

   The "site-id" leaf contains an arbitrary string to uniquely identify
   the site within the overall network infrastructure.  The format of
   the site-id is determined by the local administration of the VPN
   service.

5.1.3.1.2.  Site Management

   The "management" sub-container is intended for site management
   options, depending on the device ownership and security access
   control.  The followings are three common management models:

   CE Provider Managed :  The provider has the sole ownership of the CE
      device.  Only the provider has access to the CE.  The
      responsibility boundary between SP and customer is between CE and
      customer network.  This is the most common use case.

   CE Customer Managed :  The customer has the sole ownership of the CE
      device.  Only the customer has access to the CE.  In this model,
      the responsibility boundary between SP and customer is between PE
      and CE.

   CE Co-managed :  The provider has ownership of the CE device and
      responsible for managing the CE.  However, the provider grant the
      customer accessing the CE for some configuration/monitoring
      purpose.  In this co-managed mode the responsibility boundary is
      the same as the provider-managed model.

   The selected management mode is specified under the "type" leaf.  The
   "address" leaf stores CE device management IP information.  And "
   management-transport" leaf is used to identify the transport protocol
   for management traffic, IPv4 or IPv6.  Additional security options
   MAY be derived based on the particular management model selected.





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5.1.3.1.3.  Site Location

   The information in the "location" sub-container under a "site" allows
   easy retrieval on nearest available facility for access topology
   planning.  It may also be used by other network orchestration
   component to decide the targeted upstream PE.  Location is express in
   terms of postal information.

5.1.3.1.4.  Site Diversity

   Some subscriber may request upstream PE diversity between two or more
   sites.  These sites will share the same diversity group ID under the
   optional "site-diversity" sub-container.

5.1.3.1.5.  Site Security

   This sub-container is is a placeholder for site-security options.  It
   presents parameters for ingress service stream admission control and
   encryption profile information.

5.1.3.1.6.  Site Signaling Option

   See Section 5.1.2.4.

5.1.3.1.7.  Site Load Balance Options

   TBD.

5.1.3.1.8.  Ports

   The L2SM includes a set of essential physical interface properties
   and Ethernet layer characteristics in the "port" sub-container.  Some
   of these are critical implementation arrangements that require
   consent from both subscriber and provider.

5.1.3.1.8.1.  ID

   "id" is a free-form string to identify a given interface.  Service
   provider can decide on the actual nomenclature used in the management
   systems.

5.1.3.1.8.2.  Remote Carrier Name

   TBD.







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5.1.3.1.8.3.  Fate Sharing Group

   TBD.

5.1.3.1.8.4.  Bearer

   Under port, there is a bearer container that presents two sets of
   link attributes: physical or optional LAG interface attributes.
   These parameters are essential for the connection between subscriber
   and provider edge devices to establish properly.

   For each physical interface (phy-interface), there are basic
   configuration parameters like port number and speed, interface face
   MTU, auto-negotiation and flow-control settings, etc.
   "encapsulation-type" is for user to select between Ethernet
   encapsulation (port-based) or Ethernet VLAN encapsulation (VLAN-
   based).  All allowed Ethertypes of ingress service frames can be
   listed under "ethertype".  In addition, the subscriber and provider
   may decide to enable advanced features, such as LLDP, 802.3AH link
   OAM, MAC loop detection/prevention at a UNI, based on mutual
   agreement.

   Sometimes the subscriber may require multiple physical links bundled
   together to form single logical point-to-point LAG connection to the
   service provider.  Typically, LACP (Link Aggregation Control
   Protocol) is used to dynamically manage adding or deleting member
   links of the aggregate group.  In general, LAG allows for increased
   service bandwidth beyond the speed of a single physical link while
   providing graceful degradation as failure occurs, thus increased
   availability.

   In the L2SM, there is a set of attributes under "LAG-interface"
   related to link aggregation functionality.  The subscriber and
   provider first need to decide on whether LACP PDU will be exchanged
   between the edge device by specifying the "LACP-state" to "On" or
   "Off".  If LACP is to be enabled, then both parties need to further
   specify whether it will be running in active versus passive mode,
   plus the time interval and priority level of the LACP PDU.
   Subscriber and provider can also determine the minimum aggregate
   bandwidth for a LAG group to be considered valid path by specifying
   the optional "mini-link" attribute.  To enable fast detection of
   faulty links, Micro-BFD runs independent UDP sessions to monitor the
   status of each member link.  Subscriber and provider should consent
   to the BFD hello interval and hold time.

   Each member link will be listed under the LAG interface with basic
   physical link properties.  Certain attributes like flow-control,




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   encapsulation type, allowed ingress Ethertype and LLDP settings are
   at the LAG level.

   If the Ethernet service is enabled on a logical unit on the
   connection at the interface, the "sub-if-id" should be specified.

5.1.3.1.8.5.  Ethernet Connection

   The "Ethernet-connection" container presents site specific (S-tag,
   C-tag) management options.  The overall S-tag for the Ethernet
   circuit and C-tag to EVC mapping, if applicable, has been placed in
   the service container.  The S-tag under "port" should match the S-tag
   in service container in most cases.  However, vlan translation is
   required for the S-tag in certain deployment at the external facing
   interface or upstream PEs to "normalize" the outer VLAN tag to the
   service S-tag into the network and translate back to the site' S-tag
   in the opposite direction.  One example of this is, with Layer 2
   aggregation switch alone the path, the S-tag for the EVC has been
   previously assigned to another service thus can not be used by this
   attachment circuit.  Another use case is when multiple E-access OVCs
   from the same E-NNI interfaces are attached to the same E-LAN
   service.

   The "svlan-id-ethernet-tag" in the "Ethernet-connection" container is
   either the S-tag inserted at a UNI or the outer tag of ingress
   packets at an E-NNI.  These parameters are included in the L2SM to
   facilitate other management system to generate proper configuration
   for the network elements.

   "Ethernet-connection" container also contains optional site-specific
   C-tag to EVC mapping.

5.1.3.1.8.6.  EVC MTU

   The maximum MTU of subscriber service frames can be derived from the
   physical interface MTU by default, or specified under the "evc-mtu"
   leaf if it is different than the default number.

5.1.3.1.8.7.  MAC Address Limit

   The service provider may choose to impose a per attachment circuit
   "mac-addr-limit" in addition to the service-lever MAC limit, and
   specify the exceeding options accordingly.








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5.1.3.1.8.8.  Multihoming

   EVPN supports PE geo-redundancy in the access domain.  The connection
   between a multi-homed CE to PE is identified with a uniquely assigned
   ID referred as an Ethernet Segment Identifier (ESI).  Because a
   learned MAC address is propagated via BGP, it allows for multiple
   active paths in forwarding state and load-balancing options.

   The "multihoming" container contains ESI and redundancy mode
   attribute for EVPN multi-homing site.

5.1.3.1.8.9.  L2CP-Control

   To facilitate interoperability between different MSOs, MEF has
   provided normative guidance on Layer 2 control protocol (L2CP)
   processing requirements for each service type.  Subscriber and
   provider should make pre-arrangement on whether to allow interaction
   between the edge device or keep each others control plane separate on
   a per protocol base.

   The destination MAC addresses of these L2CP PDUs fall within two
   reserved blocks specified by IEEE 802.1 Working Group.  Packet with
   destination MAC in these multicast ranges has special forwarding
   rules.

   o  Bridge Block of Protocols: 01-80-C2-00-00-00 through
      01-80-C2-00-00-0F

   o  MRP Block of Protocols: 01-80-C2-00-00-20 through
      01-80-C2-00-00-2F

   Layer 2 protocol tunneling allows service providers to pass
   subscriber Layer 2 control PDUs across the network without being
   interpreted and processed by intermediate network devices.  These
   L2CP PDUs are transparently encapsulated across the MPLS-enabled core
   network in Q-in-Q fashion.

   The "L2CP-control" container contains the list of commonly used L2CP
   protocols.  Service provider can specify DISCARD, PEER or TUNNEL
   action for each individual protocol.

   In addition, "provider-bridge-group" and "provider-bridge-mvrp"
   addresses are also listed in the L2CP container.








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5.1.3.1.8.10.  Service Profile

   In MEF 23.2 ([MEF-23-2]) two types of model are defined as the
   following:

   Class-of-Service Identifier based on EVC or OVC EP (End Point):  In
      this model, regardless of customer marking, all in-profile frames
      will be marked with service level in contractual agreement.
      Customer CoS markings are preserved throughout the provider
      network.  The bandwidth profile consists of one set of CIR/CBS and
      EIR/EBS values.

   Class-of-Service Identifier based on Priority Code Point:  Using this
      model, multiple classes of services can be associated with a
      single customer EVC, identified by dot1p bits in the C-tag.  Each
      service level has its own individual bandwidth profile.  Out-of-
      profile packets will be discarded.  Customer CoS markings are
      preserved.

   Class-of-Service Identifier based on DSCP:  Using this model,
      multiple classes of services can be associated with a single
      customer EVC, identified by DSCP bits in the IP header.  Each
      service level has its own individual bandwidth profile.  Out-of-
      profile packets will be discarded.  Customer CoS markings are
      preserved.

   Similarly, Color-identifier can be assigned based on EVC or OVC EP,
   dot1p value in C-tag, or DSCP in IP header.  Ingress service frames
   are metered against the bandwidth profile based on the cos-
   identifier.  A "color" will be assigned to a service frame to
   identify its bandwidth profile conformance.  A service frame is
   "green" if it is conformant with "committed" rate of the bandwidth
   profile.  A Service Frame is "yellow" if it is exceeding the
   "committed" rate but conformant with the "excess" rate of the
   bandwidth profile.  Finally, a service frame is "red" if it is
   conformant with neither the "committed" nor "excess" rates of the
   bandwidth profile.

   Ingress/egress-bandwidth-profile-per-evc presents the ingress/egress
   bandwidth profile per EVC, providing rate enforcement for all ingress
   service frames at the interface that are associated with a particular
   EVC.

   Alternately, ingress/egress-bandwidth-profile-per-cos-id presents the
   ingress/egress bandwidth profile per CoS, providing rate enforcement
   for all service frames for a given class of service.  The class of
   service is identified via a CoS identifier.  So this bandwidth
   profile applies to service frames over an EVC with a particular CoS



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   value.  Multiple ingress/egress-bandwidth-profile-per-cos-id can be
   associated with the same EVC.

   The optional "byte-offset" indicates how many bytes in the service
   frame header are excluded from rate enforcement.

5.1.3.1.8.11.  BUM Strom Control

   For point-to-point E-LINE services, the provider only needs to
   deliver a single copy of each service frame to the remote PE,
   regardless whether the destination MAC address of the incoming frame
   is unicast, multicast or broadcast.  Therefore, all in-profile
   service frames should be delivered unconditionally.

   B-U-M (Broadcast-UnknownUnicast-Multicast) frame forwarding in
   multipoint-to-multipoint services, on the other hand, involves both
   local flooding to other attachment circuits on the same PE and remote
   replication to all other PEs, thus consumes additional resources and
   core bandwidth.  Special B-U-M frame disposition rules can be
   implemented at external facing interfaces (UNI or E-NNI) to rate-
   limit the B-U-M frames, in term of number of packets per second or
   bits per second.

   The threshold can apply to all B-U-M traffic, or one for each
   category.

5.1.3.1.8.12.  MAC Loop Protection

   MAC address flapping between different physical ports typically
   indicates a bridge loop condition in the subscriber network.
   Misleading entries in the MAC cache table can cause service frames to
   circulate around the network indefinitely and saturate the links
   throughout the provider's network, affecting other services in the
   same network.  In case of EVPN, it also introduces massive BGP
   updates and control plane instability.

   Service provider may opt to implement switching loop prevention
   mechanism at the external facing interfaces for multipoint-to-
   multipoint services by imposing a MAC address move threshold.

   The MAC move rate and prevention-type options are listed in the "mac-
   loop-prevention" container.

5.1.3.1.8.13.  Ethernet Service OAM

   The advent of Ethernet as wide-area network technology brings
   additional requirements of end-to-end service monitoring and fault
   management in the carrier network, particularly in the area of



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   service availability and Mean Time To Repair (MTTR).  Ethernet
   Service OAM in the L2SM refers to the combined protocol suites of
   IEEE 802.1ag ([IEEE-802-1ag]) and ITU-T Y.1731 ([ITU-T-Y-1731]).

   Generally speaking, Ethernet Service OAM enables service provider to
   perform service continuity check, fault-isolation, and packet delay/
   jitter measurement at per customer per EVC granularity.  The
   information collected from Ethernet Service OAM data sets is
   complementary to other higher layer IP/MPLS OSS tools to ensure the
   required service level agreements (SLAs) can be meet.

   The 802.1ag Connectivity Fault Management (CFM) functional model is
   structured with hierarchical maintenance domains (MD), each assigned
   a unique maintenance level.  Higher level MD can be nested over lower
   level MD.  However, the MD can not intersect.  The scope of each MD
   can be solely within a subscriber's network, solely within the
   provider's network, interact between the subscriber-to-provider or
   provider-to-provider edge equipment, or tunnel over another
   provider's network.

   Depending on the use case scenario, one or more maintenance end point
   (MEP) can be placed on the external facing interface, sending CFM
   PDUs towards the core network (UP MEP) or downstream link (DOWN MEP).

   The "cfm-802.1-ag" sub-container under "port" currently presents two
   types of CFM maintenance association (MA): UP MEP for UNI-N to UNI-N
   MA and DOWN MEP for UNI-N to UNI-C MA.  For each MA, user can define
   the maintenance domain ID (MAID), MEP level, MEP direction, remote
   MEP ID, CoS level of the CFM PDUs, Continuity Check Message (CCM)
   interval and hold time, alarm priority defect, CCM priority-type,
   etc.

   ITU-T Y.1731 Performance Monitoring (PM) provides essential network
   telemetry information that includes the measurement of Ethernet
   service frame delay, frame delay variation, frame loss, and frame
   throughput.  The delay/jitter measurement can be either one-way or
   two-way.  Typically, a Y.1731 PM probe sends a small amount of
   synthetic frames along with service frames to measure the SLA
   parameters.

   The "y-1731" sub-container under "port" contains a set of parameters
   for use to define the PM probe information, including MAID, local and
   remote MEP-ID, PM PDU type, message period and measurement interval,
   CoS level of the PM PDUs, loss measurement by synthetic or service
   frame options, one-way or two-way delay measurement, PM frame size,
   and session type.





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6.  Interaction with Other YANG Modules

   As expressed in Section 4, this service module is not intended to
   configure the network element, but is instantiated in a management
   system.

   The management system might follow modular design and comprise at
   least two different components:

   a.  The component instantiating the service model (let' call it the
       service component)

   b.  The component responsible for network element configuration
       (let's call it the configuration component)

   In some cases when the split is needed between the behavior and
   functions that a customer requests and the technology that the
   network operator has available to deliver the service
   [I-D.wu-opsawg-service-model-explained].  A new component can be
   separated out of the service component (let's call it the control
   component).  This component is responsible for network-centric
   operation and is aware of many features such as topology, technology,
   and operator policy.  As an optional component, it can use service
   model as input and is not required if the control component delegates
   its control operations to the configuration component.

   In Section 7 we provide some example of translation of service
   provisioning request to router configuration lines as an
   illustration.  In the NETCONF/YANG ecosystem, it is expected that
   NETCONF and YANG will be used between the configuration component and
   network elements to configure the requested service on those
   elements.

   In this framework, it is expected that YANG models will be used for
   configuring service components on network elements.  There will be a
   strong relationship between the abstracted view provided by this
   service model and the detailed configuration view that will be
   provided by specific configuration models for network elements such
   as those defined in [I-D.ietf-bess-l2vpn-yang] and
   [I-D.ietf-bess-evpn-yang].  Service components needing configuration
   on network elements in support of the service model defined in this
   document include:

   o  VRF definition including VPN policy expression.

   o  Physical interface.

   o  Ethernet layer (VLAN ID).



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   o  QoS : classification, profiles, etc.

   o  Routing protocols : support of configuration of all protocols
      listed in the document, as well as routing policies associated
      with these protocols.

   o  Multicast Support.

   o  Ethernet Service OAM Support.

7.  Service Model Usage Example

   *** TBD ***

8.  YANG Module


   <CODE BEGINS>
   file "ietf-l2vpn-svc@2016-09-29.yang"
   module ietf-l2vpn-svc {
     namespace "urn:ietf:params:xml:ns:yang:ietf-l2vpn-svc";
     prefix "l2svc";
     import ietf-inet-types {
       prefix inet;
     }
     import ietf-yang-types {
       prefix yang;
     }
     organization
       "IETF L2SM Working Group.";
     contact
       "WG List: l2sm@ietf.org
        Editor: Bin_Wen@comcast.com";
     description
       "The YANG module defines a generic service configuration
        model for Layer 2 VPN services common across all of the
        vendor implementations.";
     revision 2016-10-15 {
       description
         "Initial revision.";
       reference
         "draft-wen-l2sm-l2vpn-service-model-01.txt
          A YANG Data Model for L2VPN Service Delivery.";
     }

     /* Features */

     feature oam-3ah {



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       description
         "Enables support of OAM 802.3ah";
     }

     feature Micro-BFD {
       description
         "Enables support of Micro-BFD";
     }

     feature bfd {
       description
         "Enables support of BFD";
     }

     feature signaling-option {
       description
         "Enable support of signaling option";
     }

     feature site-diversity {
       description
         "Enables support of site diversity constraints";
     }

     feature encryption {
       description
         "Enables support of encryption";
     }

     /* Typedefs */

     typedef ccm-priority-type {
       type uint8 {
         range "0..7";
       }
       description
         "A 3 bit priority value to be used in the VLAN tag, if present
          in the transmitted frame.";
     }
     typedef control-mode {
       type enumeration {
         enum peer {
           description
             "Peer mode";
         }
         enum tunnel {
           description
             "Tunnel mode";



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         }
         enum discard {
           description
             "Discard mode";
         }
      }
      description
        "Defining a type of the control mode";
     }

     /* Identities */

     identity site-type {
       description
         "Identity of site type.";
     }

     identity uni {
       base site-type;
       description
         "Identity of User Network Interface ";
     }

     identity enni {
      base site-type;
      description
        "Identity of External Network to Network Interface";
     }

     identity color-id {
       description
         "Identity of color id";
     }

     identity color-id-evc {
       base color-id;
       description
         "Identity of color id base on EVC";
     }

     identity color-id-evc-cvlan {
       base color-id;
       description
         "Identity of color id base on EVC and CVLAN ";
     }

     identity cos-id {
       description



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         "Identity of class of service id";
     }

     identity cos-id-evc {
       base cos-id;
       description
         "Identity of cos id based on EVC";
     }

     identity cos-id-evc-pcp {
       base cos-id;
       description
         "Identity of cos id based on EVC and PCP";
     }

     identity cos-id-evc-dscp {
       base cos-id;
       description
         "Identity of cos id based on EVC and DSCP";
     }

     identity cos-id-ovc-ep {
       base cos-id;
       description
         "Identity of cos id based on OVC EP";
     }

     identity performance-tier-option {
       description
         "Identity of performance tier option.";
     }

     identity metro {
       base performance-tier-option;
       description
         "Identity of metro";
     }

     identity regional {
       base performance-tier-option;
       description
         "Identity of regional";
     }

     identity continental {
       base performance-tier-option;
       description
         "Identity of continental";



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     }

     identity global {
       base performance-tier-option;
       description
         "Identity of global";
     }

     identity policing {
       description
         "Identity of policing type";
     }

     identity one-rate-two-color {
       base policing;
       description
         "Identity of one-rate, two-color (1R2C)";
     }

     identity two-rate-three-color {
       base policing;
       description
         "Identity of two-rate, three-color (2R3C)";
     }

     identity BUM-type {
       description
         "Identity of BUM type";
     }

     identity broadcast {
       base BUM-type;
       description
         "Identity of broadcast";
     }

     identity unicast {
       base BUM-type;
       description
         "Identity of unicast";
     }

     identity multicast {
       base BUM-type;
       description
         "Identity of multicast";
     }




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     identity loop-prevention-type{
       description
         "Identity of loop prevention";
     }

     identity shut {
       base loop-prevention-type;
       description
         "Identity of shut protection";
     }

     identity trap {
       base loop-prevention-type;
       description
         "Identity of trap protection";
     }

     identity lacp-state {
       description
         "Identity of LACP state";
     }

     identity lacp-on {
       base lacp-state;
       description
         "Identity of LCAP on";
     }

     identity lacp-off {
       base lacp-state;
       description
         "Identity of LACP off";
     }

     identity lacp-mode {
       description
         "Identity of LACP mode";
     }

     identity lacp-passive {
       base lacp-mode;
       description
         "Identity of LACP passive";
     }

     identity lacp-active {
       base lacp-mode;
       description



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         "Identity of LACP active";
     }

     identity lacp-speed {
       description
         "Identity of LACP speed";
     }

     identity lacp-fast {
       base lacp-speed;
       description
         "Identity of LACP fast";
     }

     identity lacp-slow {
       base lacp-speed;
       description
         "Identity of LACP slow";
     }

     identity vpn-signaling-type {
        description
          "Identity of VPN signaling types";
     }

     identity vrf {
       base vpn-signaling-type;
       description
         "Virtual routing and forwarding (VRF).";
     }

     identity vfi {
       base vpn-signaling-type;
       description
         "Virtual forwarder interface";
     }

     identity evi {
       base vpn-signaling-type;
       description
         "Ethernet virtual interconnect.";
     }

     identity l2vpn-type {
       description
         "Layer 2 VPN types";
     }




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     identity vpws {
       base l2vpn-type;
       description
         "Virtual Private Wire Service";
     }

     identity vpls {
       base l2vpn-type;
       description
         "Virtual Private LAN Service";
     }

     identity evpn {
       base l2vpn-type;
       description
         "Ethernet VPN";
     }

     identity management {
       description
         "Base identity for site management scheme.";
     }

     identity co-managed {
       base management;
       description
         "Base identity for co-managed site.";
     }

     identity customer-managed {
       base management;
       description
         "Base identity for customer managed site.";
     }

     identity provider-managed {
       base management;
       description
         "Base identity for provider managed site.";
     }

     identity address-family {
       description
         "Base identity for an address family.";
     }

     identity ipv4 {
       base address-family;



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       description
         "Identity for IPv4 address family.";
     }

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

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

     identity any-to-any {
       base vpn-topology;
       description
         "Identity for any to any VPN topology.";
     }

     identity hub-spoke {
       base vpn-topology;
       description
         "Identity for Hub'n'Spoke VPN topology.";
     }

     identity hub-spoke-disjoint {
       base vpn-topology;
       description
         "Identity for Hub'n'Spoke VPN topology
          where Hubs cannot talk between each other.";

     }

     identity site-role {
       description
         "Base identity for site type.";
     }

     identity any-to-any-role {
       base site-role;
       description
         "Site in an any to any IPVPN.";
     }

     identity spoke-role {
       base site-role;



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       description
         "Spoke Site in a Hub &amp; Spoke IPVPN.";
     }

     identity hub-role {
       base site-role;
       description
         "Hub Site in a Hub &amp; Spoke IPVPN.";
     }

     identity pm-type {
       description
         "Performance monitor type";
     }

     identity loss {
       base pm-type;
       description
         "Loss measurement";
     }

     identity delay {
       base pm-type;
       description
         "Delay measurement";
     }

     identity fault-alarm-defect-type {
       description
         "Indicating the alarm priority defect";
     }

     identity remote-rdi {
       base fault-alarm-defect-type;
       description
         "Indicates the aggregate health of the remote MEPs.";
     }

     identity remote-mac-error {
       base fault-alarm-defect-type;
       description
         "Indicates that one or more of the remote MEPs is
          reporting a failure in its Port Status TLV or
          Interface Status TLV.";
     }

     identity remote-invalid-ccm {
       base fault-alarm-defect-type;



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       description
         "Indicates that at least one of the Remote MEP
          state machines is not receiving valid CCMs
          from its remote MEP.";
      }

      identity invalid-ccm {
        base fault-alarm-defect-type;
        description
          "Indicates that one or more invalid CCMs has been
           received and that 3.5 times that CCMs transmission
           interval has not yet expired.";
      }

      identity cross-connect-ccm {
        base fault-alarm-defect-type;
        description
          "Indicates that one or more cross connect CCMs has been
           received and that 3.5 times of at least one of those
           CCMs transmission interval has not yet expired.";
      }

     /* Groupings */

     grouping customer-info-grouping {
       list customer-info {
         key "customer-account-number customer-name";
         leaf customer-account-number {
           type uint32;
           description
             "Customer account number";
         }
         leaf customer-name {
           type string;
           description
             "Customer name";
         }
         container customer-operation-center {
           leaf customer-noc-street-address {
             type string;
             description
               "Customer NOC street Address.";
           }
           container customer-noc-phone-number {
             leaf main-phone-num {
               type uint32;
               description
                 "Main phone number.";



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             }
             leaf extension-options {
               type uint32;
               description
                 "Extension or options";
             }
             description
               "Configuration of customer NOCc phone number";
           }
           description
             "Configuration of customer operation center";
         }
         description
           "List of customer information";
       }
       description
         "Grouping for customer information";
     }

     grouping site-device {
       container device {
        list devices {
         key "device-id";
         leaf device-id {
          type string;
          description
          "Device ID";
         }
         leaf site-name {
           type string;
           description
             "Site name";
         }
         leaf address {
           type inet:ip-address;
           description
           "Address";
         }
         leaf management-transport {
           type identityref {
             base address-family;
           }
           description
             "Transport protocol used for management.";
         }
         description
           "List of devices";
        }



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        description
          "Devices configuration";
       }
       description
         "Device parameters for the site.";
     }

     grouping site-management {
       container managemnt {
         leaf type {
           type identityref {
             base management;
           }
           description
             "Management type of the connection.";
         }
         description
           "Container for management";
       }
      description
        "Grouping for management";
     }

     grouping customer-location-info {
       container location {
         leaf address {
           type string;
           description
             "Address (number and street) of the site.";
         }
         leaf zip-code {
           type string;
           description
             "ZIP code of the site.";
         }
         leaf state {
           type string;
           description
             "State of the site. This leaf can also be used to
             describe a region for country who does not have
             states.";
         }
         leaf city {
           type string;
           description
             "City of the site.";
         }
         leaf country-code {



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           type string;
           description
             "Country of the site.";
         }
         description
           "Location of the site.";
       }
       description
         "This grouping defines customer location parameters";
      }

      grouping site-diversity {
        container site-diversity {
          if-feature site-diversity;
          container groups {
            list group {
              key group-id;
              leaf group-id {
                type string;
                description
                  "Group-id the site is belonging to";
                }
              description
                "List of group-id";
            }
            description
              "Groups the site is belonging to.
               All site network accesses will inherit those group
               values.";
          }
          description
            "Diversity constraint type.";
        }
        description
          "This grouping defines site diversity parameters";
      }

      grouping site-service {
        leaf svlan-id-ethernet-tag {
          type string;
           description
             "SVLAN-ID/Ethernet Tag configurations";
        }
        leaf cvlan-id-to-evc-map {
         type string;
          description
            "List of CVLAN-ID to EVC Map configurations";
        }



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        leaf service-level-mac-limit {
          type string;
          description
            "Service-level MAC-limit (E-LAN only)";
        }
        description
          "This grouping defines site service parameters";
      }

      grouping service-protection {
        container service-protection {
          container protection-model {
            description
              "Container of protection model configurations";
          }
          container peer-evc-id {
            description
              "Container of peer EVC ID configurations";
          }
          description
            "Container of End-to-end Service Protection
            configurations";
        }
        description
          "Grouping for service protection";
      }

      grouping ethernet-service-type {
        choice ethernet-svc-type {
          case e-line {
            leaf epl {
              type boolean;
              description
                "Ethernet private line";
            }
            leaf evpl {
              type boolean;
              description
                "Ethernet virtual private line";
            }
            description
              "Case of e-line";
          }
          case e-lan {
            leaf ep-lan {
              type boolean;
              description
                "Ethernet private LAN";



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            }
            leaf evp-lan {
              type boolean;
              description
                "Ethernet virtual private LAN";
            }
            description
              "Case of e-lan";
          }
          case e-access {
            leaf access-epl {
              type boolean;
              description
                "Access Ethernet virtual private line";
            }
            leaf access-evpl {
              type boolean;
              description
                "Access Ethernet virtual private line";
            }
            description
              "Case of e-access.";
          }
          description
            "Choice of Ethernet service type";
        }
        description
          "Grouping for Ethernet service type.";
      }

      grouping signaling-option-grouping {
        list signaling-option {
          key "name type";
          leaf name {
            type string;
            description
              "VRF/VFI/EVI Name";
          }
          leaf type {
            type identityref {
              base vpn-signaling-type;
            }
            description
              "VPN signaling types";
          }
          container mp-bgp-l2vpn {
            leaf vpn-id {
              type string;



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              description
                "Identifies the target VPN";
            }
            leaf type {
              type identityref {
                base l2vpn-type;
              }
              description
                "L2VPN types";
            }
            description
              "Container for MP BGP L2VPN";
          }
          container mp-bgp-evpn {
            leaf vpn-id {
              type string;
              description
                "Identifies the target VPN";
            }
            leaf type {
              type identityref {
                base l2vpn-type;
              }
              description
                "L2VPN types";
            }
            description
              "Container for MP BGP L2VPN";
          }
          container t-ldp-pwe {
            list PE-EG-list {
              key "service-ip-lo-addr vc-id";
              leaf service-ip-lo-addr {
                type inet:ip-address;
                description
                  "Service ip lo address";
              }
              leaf vc-id {
                type string;
                description
                "VC id";
              }
              description
                "List of PE/EG";
            }
            description
              "Container of T-LDP PWE configurations";
          }



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          container pwe-encapsulation-type {
            leaf ethernet {
              type boolean;
              description
                "Ethernet";
            }
            leaf vlan {
              type boolean;
              description
                "VLAN";
            }
            description
              "Container of PWE Encapsulation Type configurations";
          }
          container pwe-mtu {
            leaf allow-mtu-mismatch {
              type boolean;
              description
                "Allow MTU mismatch";
            }
            description
              "Container of PWE MTU configurations";
          }
          container control-word {
            description
              "Container of control word configurations";
          }
          description
            "List of VPN Signaling Option.";
        }
        description
          "Grouping for signaling option";
      }

      grouping load-balance-grouping {
        leaf fat-pw {
          type boolean;
          description
            "Fat label is applied to Pseudowires across MPLS
             network";
        }
        leaf entropy-label {
          type boolean;
          description
            "Entropy label is applied to IP forwarding,
             L2VPN or L3VPN across MPLS network";
        }
        leaf vxlan-source-port {



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          type string;
          description
            "Vxlan source port";
        }
       description
         "Grouping for load balance ";
     }

     grouping intra-mkt-grouping {
       list intra-mkt {
         key "metro-mkt-id mkt-name";
         leaf metro-mkt-id {
           type uint32;
           description
             "Metro MKT ID";
         }
         leaf mkt-name {
           type string;
           description
             "MKT Name";
         }
         description
           "List of intra-MKT";
       }
       description
         "Grouping for intra-MKT";
     }

     grouping inter-mkt-service {
       leaf inter-mkt-service{
         type boolean;
         description
           "Indicate whether service is inter market service.";
       }
       description
         "Grouping for inter-MKT service";
     }

     grouping evc-id-grouping {
       leaf evc-id {
         type boolean;
         description
           "Ethernet Virtual Connection identifier";
       }
       description
         "Grouping for EVC-ID";
     }




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     grouping svc-type-grouping {
       container svc-type {
         container evc {
           leaf evc-id {
             type boolean;
             description
               "Indicate whether the Ethernet virtual connection
                id support.";
           }
           leaf number-of-pe {
             type uint32;
             config false;
             description
               "Number of PEs";
           }
           leaf number-of-site {
             type uint32;
             config false;
             description
               "Number of Sites";
           }
           description
             "Container for Ethernet virtual connection.";
         }
         container ovc {
           leaf on-net-ovc-id {
             type boolean;
             description
               "Indicate whether the on net OVC id support.";
           }
           leaf off-net-ov-id {
             type boolean;
             description
               "Indicate whether the off net OVC id support.";
           }
           description
             "Container for OVC";
         }
         description
           "Container for service types.";
       }
       description
         "Grouping of service types.";
     }

     grouping cfm-802-grouping {
       leaf MAID {
         type string;



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         description
           "MA ID";
       }
       leaf mep-id {
        type uint32;
        description
          "Local MEP ID";
       }
       leaf mep-level {
         type uint32;
         description
           "MEP level";
       }
       leaf mep-up-down {
         type enumeration {
           enum up {
             description
               "MEP up";
           }
           enum down {
             description
               "MEP down";
           }
         }
         description
           "MEP up/down";
       }
       leaf remote-mep-id {
         type uint32;
         description
           "Remote MEP ID";
       }
       leaf cos-for-cfm-pdus {
         type uint32;
         description
           "COS for CFM PDUs";
       }
       leaf ccm-interval {
         type uint32;
         description
           "CCM interval";
       }
       leaf ccm-holdtime {
         type uint32;
         description
           "CCM hold time";
       }
       leaf alarm-priority-defect {



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         type identityref {
           base fault-alarm-defect-type;
         }
         description
          "The lowest priority defect that is
           allowed to generate a Fault Alarm.
           The non-existence of this leaf means
           that no defects are to be reported";
       }
       leaf ccm-p-bits-pri {
         type ccm-priority-type;
         description
           "The priority parameter for CCMs transmitted by the MEP";
       }
       description
         "Grouping for 802.1ag CFM attribute";
     }

     grouping y-1731{
       list y-1731 {
         key MAID;
         leaf MAID {
           type string;
           description
             "MA ID ";
         }
         leaf mep-id {
           type uint32;
           description
             "Local MEP ID";
         }
         leaf type {
           type identityref {
             base pm-type;
           }
           description
             "Performance monitor types";
         }
         leaf remote-mep-id {
           type uint32;
           description
             "Remote MEP ID";
         }
         leaf message-period {
           type uint32;
           description
             "Defines the interval between OAM messages. The message
              period is expressed in milliseconds";



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         }
         leaf measurement-interval {
           type uint32;
           description
             "Specifies the measurement interval for statistics. The
              measurement interval is expressed in seconds";
         }
         leaf cos {
           type uint32;
           description
             "Class of service";
         }
         leaf loss-measurement {
           type boolean;
           description
             "Whether enable loss measurement";
         }
         leaf synthethic-loss-measurement {
           type boolean;
           description
             "Indicate whether enable synthetic loss measurement";
         }
         container delay-measurement {
           leaf enable-dm {
             type boolean;
             description
               "Whether to enable delay measurement";
           }
           leaf two-way {
             type boolean;
             description
               "Whether delay measurement is two-way (true) of one-
               way (false)";
           }
           description
             "Container for delay measurement";
         }
         leaf frame-size {
           type uint32;
           description
             "Frame size";
         }
         leaf session-type {
           type enumeration {
             enum proactive {
               description
                 "Proactive mode";
             }



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             enum on-demand {
               description
                 "On demand mode";
             }
           }
           description
             "Session type";
         }
         description
           "List for y-1731.";
       }
       description
         "Grouping for y.1731";
     }

     grouping enni-site-info-grouping {
       container site-info {
         leaf site-name {
           type string;
           description
             "Site name";
         }
         leaf address {
           type inet:ip-address;
           description
             "Address";
         }
         leaf Edge-Gateway-Device-Info {
           type string;
           description
             "Edge Gateway Device Info ";
         }
         description
           "Container of site info configurations";
       }
       description
         "Grouping for site information";
     }

     grouping site-security {
       container security {
         description
           "Security parameters";
       }
       description
         "This grouping defines security parameters for a site";
     }




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     grouping lacp-grouping {
       container LACP {
         leaf LACP-state {
           type identityref {
             base lacp-state;
           }
           description
             "LACP on/off";
         }
         leaf LACP-mode {
           type identityref {
             base lacp-mode;
           }
           description
             "LACP mode";
         }
         leaf LACP-speed {
           type identityref {
             base lacp-speed;
           }
           description
             "LACP speed";
         }
         leaf mini-link {
           type uint32;
           description
             "Mini link";
         }
         leaf system-priority {
           type uint16;
           description
             "Indicates the LACP priority for the system.
              The range is from 0 to 65535.
              The default is 32768.";
         }
         container Micro-BFD {
           if-feature Micro-BFD;
           leaf Micro-BFD-on-off {
             type enumeration {
               enum on {
                 description
                   "Micro-bfd on";
               }
               enum off {
                 description
                   "Micro-bfd off";
               }
             }



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             description
               "Micro BFD ON/OFF";
           }
           leaf bfd-interval {
             type uint32;
             description
               "BFD interval";
           }
           leaf bfd-hold-timer {
             type uint32;
             description
               "BFD hold timer";
           }
           description
             "Container of Micro-BFD configurations";
         }
         container bfd {
           if-feature bfd;
           leaf bfd-enabled {
             type boolean;
             description
               "BFD activation";
           }
           choice holdtime {
             case profile {
               leaf profile-name {
                 type string;
                 description
                   "Service provider well known profile.";
               }
               description
                 "Service provider well known profile.";
             }
             case fixed {
               leaf fixed-value {
                 type uint32;
                 units msec;
                 description
                   "Expected hold time expressed in msec.";
               }
             }
             description
               "Choice for hold time flavor.";
           }
           description
             "Container for BFD.";
         }
         container Member-link-list {



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           list member-link {
             key "name";
             leaf name {
               type string;
               description
                 "Member link name";
             }
             leaf port-speed {
               type uint32;
               description
                 "Port speed";
             }
             leaf auto-neg {
               type string;
               description
                 "Auto neg";
             }
             leaf mtu {
               type uint32;
               description
                 "MTU";
             }
             container oam-802.3AH-link {
               if-feature oam-3ah;
               leaf enable {
                 type boolean;
                 description
                   "Indicate whether support oam 802.3 ah link";
               }
               description
                 "Container for oam 802.3 ah link.";
             }
             description
               "Member link";
           }
           description
             "Container of Member link list";
         }
         leaf flow-control {
           type string;
           description
             "Flow control";
         }
         leaf encapsulation-type {
           type enumeration {
             enum VLAN {
               description
                 "VLAN";



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             }
             enum ether {
               description
                 "Ethernet";
             }
           }
           description
             "Encapsulation type";
         }
         leaf ethertype {
           type string;
           description
             "Ether type";
         }
         leaf lldp {
           type boolean;
            description
              "LLDP";
         }
         description
           "LACP";
       }
       description
         "Grouping for lacp";
     }

     grouping phy-interface-grouping {
       container phy-interface {
         leaf port-number {
           type uint32;
           description
             "Port number";
         }
         leaf port-speed {
           type uint32;
           description
             "Port speed";
         }
         leaf auto-neg {
           type string;
           description
             "Auto neg";
         }
         leaf phy-mtu {
           type uint32;
           description
             "PHY MTU";
         }



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         leaf flow-control {
           type string;
           description
             "Flow control";
         }
         leaf encapsulation-type {
           type enumeration {
             enum VLAN {
               description
                 "VLAN";
             }
             enum Ethernet {
               description
                 "Ethernet";
             }
           }
           description
             "Encapsulation-type";
         }
         leaf ethertype {
           type string;
           description
             "Ethertype";
         }
         leaf lldp {
           type boolean;
           description
             "LLDP";
         }
         container oam-802.3AH-link{
          if-feature oam-3ah;
          leaf enable {
            type boolean;
            description
              "Indicate whether support oam 802.3 ah link";
          }
          description
            "Container for oam 802.3 ah link.";
         }
         leaf uni-loop-prevention {
           type boolean;
           description
             "If this leaf set to truth that the port automatically
              goes down when a physical loopback is detect.";
         }
         description
           "Container of PHY Interface Attributes configurations";
       }



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       description
         "Grouping for phy interface.";
     }

     grouping lag-interface-grouping {
       container LAG-interface {
         list LAG-interface {
           key "LAG-interface-number";
           leaf LAG-interface-number {
             type uint32;
             description
               "LAG interface number";
           }
           uses lacp-grouping;
           description
             "List of LAG interfaces";
         }
         description
           "Container of LAG interface attributes configuration";
       }
       description
         "Grouping for LAG interface";
     }

     grouping bearer-grouping {
       container bearer {
         uses phy-interface-grouping;
         uses lag-interface-grouping;
         leaf interface-description {
           type string;
           description
             "Interface description";
         }
         leaf sub-if-id {
           type uint32;
           description
             "Sub-if id";
         }
         description
           "Container for bearer";
       }
       description
       "Grouping for bearer.";
     }

     grouping ethernet-connection-grouping {
       container ethernet-connection {
         container vlan {



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           leaf svlan-id-ethernet-tag {
             type string;
             description
               "SVLAN-ID/Ethernet Tag configurations";
           }
           description
             "Abstract container for VLAN";
         }
         description
           "Container for Ethernet connection";
       }
       description
         "Grouping for Ethernet connection";
     }

     grouping evc-mtu-grouping {
       leaf evc-mtu {
         type uint32;
         description
           "EVC MTU";
       }
       description
         "Grouping for evc mtu";
     }

     grouping mac-addr-limit-grouping {
       container mac-addr-limit {
         leaf exceeding-option {
           type uint32;
           description
             "Exceeding option";
         }
         description
           "Container of MAC-Addr limit configurations";
       }
       description
         "Grouping for mac address limit";
     }

     grouping multihoming-grouping {
       container multihoming {
         list multihoming {
           key "ESI";
           leaf ESI {
             type string;
             description
               "Ethernet segment id";
           }



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           choice redundancy-mode {
             case single-active {
               leaf single-active {
                 type boolean;
                 description
                   "Single active";
               }
               description
                 "Single active case";
             }
             case all-active {
               leaf all-active {
                 type boolean;
                 description
                   "All active";
               }
               description
                 "All active case";
             }
             description
               "Redundancy mode choice";
           }
           description
             "List of multihomings";
         }
         description
           "Container of multihoming optional configurations";
       }
       description
         "Grouping for multihoming";
     }

     grouping l2cp-grouping {
       container L2CP-control {
         leaf stp-rstp-mstp {
           type control-mode;
           description
             "STP/RSTP/MSTP";
         }
         leaf pause {
           type control-mode;
           description
             "Pause";
         }
         leaf lacp-lamp {
           type control-mode;
           description
             "LACP/LAMP";



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         }
         leaf link-oam {
           type control-mode;
           description
             "Link OAM";
         }
         leaf esmc {
           type control-mode;
           description
             "ESMC";
         }
         leaf l2cp-802.1x {
           type control-mode;
           description
             "802.x";
         }
         leaf e-lmi {
           type control-mode;
           description
             "E-LMI";
         }
         leaf lldp {
           type boolean;
           description
             "LLDP";
         }
         leaf ptp-peer-delay {
           type control-mode;
           description
             "PTP peer delay";
         }
         leaf garp-mrp {
           type control-mode;
           description
             "GARP/MARP";
         }
         leaf provider-bridge-group {
           type yang:mac-address;
           description
             "Provider bridge group reserved MAC address
              01-80-C2-00-00-08";
         }
         leaf provider-bridge-mvrp {
           type yang:mac-address;
           description
             "Provider bridge MVRP reserved MAC address
              01-80-C2-00-00-0D";
         }



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         description
           "Container of L2CP control configurations";
        }
        description
          "Grouping for l2cp control";
     }

     grouping service-level-grouping {
       container service-level {
         leaf cos-identifier {
           type identityref {
            base cos-id;
           }
           description
             "COS Identifier [ EVC | EVC + PCP ]";
         }
         leaf color-identifier {
           type identityref {
            base color-id;
           }
           description
             "Color Identifier [ EVC | EVC + CVLAN ]";
         }
         leaf ingress-bw-profile-per-evc {
           type string;
           description
             "Ingress Bandwidth Profile per EVC";
         }
         leaf ingress-bw-profile-per-cos-id {
           type string;
           description
             "Ingress Bandwidth Profile per COS Identifier";
         }
         leaf egress-bw-profile-per-evc {
           type string;
           description
             "Egress Bandwidth Profile per EVC";
         }
         leaf egress-bw-profile-per-cos-id {
           type string;
           description
             "Egress Bandwidth Profile per COS Identifier";
         }
         leaf byte-offset {
           type uint16;
           description
             "For not including extra VLAN tags in the QoS
             calculation";



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         }
         leaf policing {
          type identityref {
           base policing;
          }
          description
          "The policing can be either one-rate,
          two-color (1R2C) or two-rate, three-color (2R3C)";
         }
         leaf performance-tier-option {
           type identityref {
             base performance-tier-option;
           }
           description
             "Performance tier option";
         }
         leaf COS {
           type uint32;
           description
             "Class of Service";
         }
         description
           "Container of service level configurations.";
       }
       description
         "Grouping for service level.";
     }

     grouping B-U-M-strom-control-grouping {
       container B-U-M-strom-control {
          leaf BUM-overall-rate {
            type uint32;
            description
              "overall rate for BUM";
           }
           list BUM-rate-per-type {
             key "type";
             leaf type {
               type identityref {
                 base BUM-type;
               }
               description
                 "BUM type";
             }
             leaf rate {
               type uint32;
               description
                 "rate for BUM";



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           }
           description
             "List of rate per type";
         }
         description
           "Container of B-U-M-strom-control configurations";
       }
       description
         "Grouping for B-U-M-strom-control";
     }

     grouping mac-loop-prevention-grouping {
       container mac-loop-prevention {
         leaf frequency {
           type uint32;
           description
             "Frequency";
         }
         leaf protection-type {
           type identityref {
             base loop-prevention-type;
           }
           description
             "Protection type";
         }
         leaf number-retries {
           type uint32;
           description
             "Number of retries";
         }
         description
           "Container of MAC loop prevention.";
       }
       description
         "Grouping for MAC loop prevention";
     }

     grouping ethernet-svc-oam-grouping {
       container Ethernet-Service-OAM {
         leaf MD-name{
           type string;
           description
             "Maintenance domain name";
         }
         leaf MD-level {
           type uint8;
           description
             "Maintenance domain level";



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         }
         container cfm-802.1-ag {
           list n2-uni-c {
             key "MAID";
             uses cfm-802-grouping;
             description
               "List of UNI-N to UNI-C";
           }
           list n2-uni-n {
             key "MAID";
             uses cfm-802-grouping;
             description
              "List of UNI-N to UNI-N";
           }
           description
             "Container of 802.1ag CFM configurations.";
         }
         uses y-1731;
         description
           "Container for Ethernet service OAM.";
       }
       description
         "Grouping for Ethernet service OAM.";
     }

     grouping fate-sharing-group {
       container groups {
         leaf fate-sharing-group-size {
           type uint16;
           description
             "fate sharing group size.";
         }
         list group {
           key group-id;
           leaf group-id {
             type string;
             description
               "Group-id the site network access
                is belonging to";
           }
           description
             "List of group-id";
         }
         description
           "Groups the fate sharing group member
            is belonging to";
       }
       description



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         "Grouping for Fate sharing group.";
     }

     /* MAIN L2VPN SERVICE */

     container l2vpn-svc {

       /* CUSTOMER */
       container customer-info {
         uses customer-info-grouping;
         description
           "Container of customer information configurations.";
       }

       /* SERVICE */
       container vpn-services {
         list vpn-svc {
           key "svc-id";
           leaf svc-id {
             type string;
             description
               "Defining a service id.";
           }
           uses svc-type-grouping;
           container ethernet-svc-type {
             uses ethernet-service-type;
             description
               "Container of Ethernet service type";
           }
           container metro-network-id {
             uses inter-mkt-service;
             uses intra-mkt-grouping;
             description
               "Container of Metro-Network ID configurations";
           }
           container signaling-option {
             uses signaling-option-grouping;
             description
               "Container for signaling option";
           }
           container load-balance-options{
             uses load-balance-grouping;
             description
               "Container for load balance options";
           }
           uses site-service;
           uses service-protection;
           container sla-targets {



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             description
               "Container for SLA targets";
           }
           description
             "List of vpn-svc";
         }
         description
           "Container of vpn-services configurations";
       }

       /* SITE */
       container sites {
         list site {
           key "site-id site-type";
           leaf site-id {
             type string;
             description
               "Site id";
           }
           leaf site-type {
             type identityref {
               base site-type;
             }
             description
               "Site type";
           }
           uses site-device;
           uses site-management;
           uses customer-location-info;
           uses site-diversity;
           uses site-security;
           container signaling-option {
             if-feature signaling-option;
             uses signaling-option-grouping;
             description
               "Container for signaling option";
           }
           container load-balance-options {
             uses load-balance-grouping;
             description
               "Container for load balance options";
           }
           container ports {
             list port {
               key "id";
               leaf id {
                 type string;
                 description



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                   "Identifier";
               }
               leaf remote-carrier-name {
                 when "'../site-type' = 'enni'" {
                   description
                     "Site type = enni";
                 }
                 type string;
                 description
                   "Remote carrier name";
               }
               uses fate-sharing-group;
               uses bearer-grouping;
               uses ethernet-connection-grouping;
               uses evc-mtu-grouping;
               uses mac-addr-limit-grouping;
               uses multihoming-grouping;
               uses l2cp-grouping;
               container service {
                 uses site-service;
                 uses service-level-grouping;
                 description
                   "Container for site service.";
               }
               uses B-U-M-strom-control-grouping;
               uses mac-loop-prevention-grouping;
               uses ethernet-svc-oam-grouping;
               uses site-security;
               description
                 "List of ports";
             }
             description
               "Container of port configurations";
           }
           description
             "List of sites";
         }
         description
           "Container of site configurations";
       }
       description
         "Container of l2vpn-svc configurations";
     }
   }
   <CODE ENDS>






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9.  Security Considerations

   The YANG modules defined in this document MAY be accessed via the
   RESTCONF protocol [I-D.ietf-netconf-restconf] or NETCONF protocol
   ([RFC6241].  The lowest RESTCONF or NETCONF layer requires that the
   transport-layer protocol provides both data integrity and
   confidentiality, see Section 2 in [I-D.ietf-netconf-restconf] and
   [RFC6241].  The client MUST carefully examine the certificate
   presented by the server to determine if it meets the client's
   expectations, and the server MUST authenticate client access to any
   protected resource.  The client identity derived from the
   authentication mechanism used is subject to the NETCONF Access
   Control Module (NACM) ([RFC6536]).  Other protocols to access this
   YANG module are also required to support the similar mechanism.

   The data nodes defined in the "ietf-l2vpn-svc" YANG module MUST be
   carefully created/read/updated/deleted.  The entries in the lists
   below include customer proprietary or confidential information,
   therefore only authorized clients MUST access the information and the
   other clients MUST NOT be able to access to the information.

   o  /l2vpn-svc/vpn-services/vpn-svc

   o  /l2vpn-svc/sites/site

10.  Acknowledgements

   Thanks to Qin Wu and Adrian Farrel for facilitating work on the
   initial revisions of this document.

   This document has drawn on the work of the L3SM Working Group
   expressed in [I-D.ietf-l3sm-l3vpn-service-model].

11.  IANA Considerations

   IANA is requested to assign a new URI from the IETF XML registry
   ([RFC3688]).  The following URI is suggested:


       URI: urn:ietf:params:xml:ns:yang:ietf-l2vpn-svc
       Registrant Contact: L2SM WG
       XML: N/A, the requested URI is an XML namespace


   This document also requests a new YANG module name in the YANG Module
   Names registry ([RFC6020]) with the following suggestion:





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       name: ietf-l2vpn-svc
       namespace: urn:ietf:params:xml:ns:yang:ietf-l2vpn-svc
       prefix: l2vpn-svc
       reference: RFC XXXX


12.  References

12.1.  Normative References

   [I-D.ietf-netconf-restconf]
              Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
              Protocol", draft-ietf-netconf-restconf-18 (work in
              progress), October 2016.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <http://www.rfc-editor.org/info/rfc2119>.

   [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
              DOI 10.17487/RFC3688, January 2004,
              <http://www.rfc-editor.org/info/rfc3688>.

   [RFC4448]  Martini, L., Ed., Rosen, E., El-Aawar, N., and G. Heron,
              "Encapsulation Methods for Transport of Ethernet over MPLS
              Networks", RFC 4448, DOI 10.17487/RFC4448, April 2006,
              <http://www.rfc-editor.org/info/rfc4448>.

   [RFC4761]  Kompella, K., Ed. and Y. Rekhter, Ed., "Virtual Private
              LAN Service (VPLS) Using BGP for Auto-Discovery and
              Signaling", RFC 4761, DOI 10.17487/RFC4761, January 2007,
              <http://www.rfc-editor.org/info/rfc4761>.

   [RFC4762]  Lasserre, M., Ed. and V. Kompella, Ed., "Virtual Private
              LAN Service (VPLS) Using Label Distribution Protocol (LDP)
              Signaling", RFC 4762, DOI 10.17487/RFC4762, January 2007,
              <http://www.rfc-editor.org/info/rfc4762>.

   [RFC6020]  Bjorklund, M., Ed., "YANG - A Data Modeling Language for
              the Network Configuration Protocol (NETCONF)", RFC 6020,
              DOI 10.17487/RFC6020, October 2010,
              <http://www.rfc-editor.org/info/rfc6020>.

   [RFC6241]  Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
              and A. Bierman, Ed., "Network Configuration Protocol
              (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
              <http://www.rfc-editor.org/info/rfc6241>.



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   [RFC6536]  Bierman, A. and M. Bjorklund, "Network Configuration
              Protocol (NETCONF) Access Control Model", RFC 6536,
              DOI 10.17487/RFC6536, March 2012,
              <http://www.rfc-editor.org/info/rfc6536>.

   [RFC7432]  Sajassi, A., Ed., Aggarwal, R., Bitar, N., Isaac, A.,
              Uttaro, J., Drake, J., and W. Henderickx, "BGP MPLS-Based
              Ethernet VPN", RFC 7432, DOI 10.17487/RFC7432, February
              2015, <http://www.rfc-editor.org/info/rfc7432>.

12.2.  Informative References

   [I-D.ietf-bess-evpn-yang]
              Brissette, P., Sajassi, A., Shah, H., Li, Z.,
              Tiruveedhula, K., Hussain, I., and J. Rabadan, "Yang Data
              Model for EVPN", draft-ietf-bess-evpn-yang-01 (work in
              progress), July 2016.

   [I-D.ietf-bess-l2vpn-yang]
              Shah, H., Brissette, P., Chen, I., Hussain, I., and B.
              Wen, "YANG Data Model for MPLS-based L2VPN", draft-ietf-
              bess-l2vpn-yang-00 (work in progress), June 2016.

   [I-D.ietf-l3sm-l3vpn-service-model]
              Litkowski, S., Tomotaki, L., and K. Ogaki, "YANG Data
              Model for L3VPN service delivery", draft-ietf-l3sm-l3vpn-
              service-model-18 (work in progress), October 2016.

   [I-D.wu-opsawg-service-model-explained]
              Wu, Q., LIU, S., and A. Farrel, "Service Models
              Explained", draft-wu-opsawg-service-model-explained-03
              (work in progress), September 2016.

   [IEEE-802-1ag]
              IEEE, "802.1ag - Connectivity Fault Management", December
              2007.

   [ITU-T-Y-1731]
              ITU-T, "Recommendation Y.1731 - OAM functions and
              mechanisms for Ethernet based networks", February 2008.

   [MEF-23-2]
              MEF Forum, "Implementation Agreement MEF 23.2 : Carrier
              Ethernet Class of Service - Phase 3", August 2016.







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   [RFC6624]  Kompella, K., Kothari, B., and R. Cherukuri, "Layer 2
              Virtual Private Networks Using BGP for Auto-Discovery and
              Signaling", RFC 6624, DOI 10.17487/RFC6624, May 2012,
              <http://www.rfc-editor.org/info/rfc6624>.

Authors' Addresses

   Bin Wen
   Comcast

   Email: Bin_Wen@comcast.com


   Giuseppe Fioccola
   Telecom Italia

   Email: giuseppe.fioccola@telecomitalia.it


   Chongfeng Xie
   China Telecom

   Email: xiechf@ctbri.com.cn


   Luay Jalil
   Verizon

   Email: luay.jalil@verizon.com






















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