YANG Data Model for L3VPN service delivery
draft-ietf-l3sm-l3vpn-service-model-00

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Document Type Active Internet-Draft (l3sm WG)
Authors Stephane Litkowski  , Rob Shakir  , Luis Tomotaki  , Kevin D'Souza 
Last updated 2015-07-06 (latest revision 2015-07-02)
Replaces draft-ltsd-l3sm-l3vpn-service-model
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L3SM Working Group                                          S. Litkowski
Internet-Draft                                   Orange Business Service
Intended status: Standards Track                               R. Shakir
Expires: January 3, 2016                                              BT
                                                             L. Tomotaki
                                                                 Verizon
                                                              K. D'Souza
                                                                     ATT
                                                           July 02, 2015

               YANG Data Model for L3VPN service delivery
                 draft-ietf-l3sm-l3vpn-service-model-00

Abstract

   This document defines a YANG data model that can be used to deliver a
   Layer 3 Provider Provisioned VPN service.  The document is limited to
   the BGP PE-based VPNs as described in RFC4110 and RFC4364.  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.  This model provides an abstracted
   view of the Layer 3 IPVPN service configuration components.  It will
   be 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.

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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   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."

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   This Internet-Draft will expire on January 3, 2016.

Copyright Notice

   Copyright (c) 2015 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
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   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.  Layer 3 IP VPN service model  . . . . . . . . . . . . . . . .   4
   4.  Service data model usage  . . . . . . . . . . . . . . . . . .   5
   5.  Design of the Data Model  . . . . . . . . . . . . . . . . . .   6
     5.1.  VPN service overview  . . . . . . . . . . . . . . . . . .   9
       5.1.1.  VPN service topology  . . . . . . . . . . . . . . . .  10
         5.1.1.1.  Route Target allocation . . . . . . . . . . . . .  10
         5.1.1.2.  Any to any  . . . . . . . . . . . . . . . . . . .  11
         5.1.1.3.  Hub and Spoke . . . . . . . . . . . . . . . . . .  11
         5.1.1.4.  Hub and Spoke disjoint  . . . . . . . . . . . . .  12
       5.1.2.  Cloud access  . . . . . . . . . . . . . . . . . . . .  13
       5.1.3.  Multicast service . . . . . . . . . . . . . . . . . .  15
     5.2.  Site overview . . . . . . . . . . . . . . . . . . . . . .  16
       5.2.1.  Deciding where to connect the site  . . . . . . . . .  17
         5.2.1.1.  Site location . . . . . . . . . . . . . . . . . .  17
         5.2.1.2.  Site availability . . . . . . . . . . . . . . . .  18
         5.2.1.3.  Site diversity  . . . . . . . . . . . . . . . . .  20
         5.2.1.4.  Route Distinguisher and VRF allocation  . . . . .  22
       5.2.2.  VPN policy  . . . . . . . . . . . . . . . . . . . . .  22
       5.2.3.  Security  . . . . . . . . . . . . . . . . . . . . . .  23
         5.2.3.1.  Encryption  . . . . . . . . . . . . . . . . . . .  23
       5.2.4.  Management  . . . . . . . . . . . . . . . . . . . . .  24
       5.2.5.  Attachment  . . . . . . . . . . . . . . . . . . . . .  24
         5.2.5.1.  Bearer  . . . . . . . . . . . . . . . . . . . . .  24
         5.2.5.2.  Connection  . . . . . . . . . . . . . . . . . . .  24
       5.2.6.  MPLS  . . . . . . . . . . . . . . . . . . . . . . . .  31

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       5.2.7.  Service . . . . . . . . . . . . . . . . . . . . . . .  32
         5.2.7.1.  QoS . . . . . . . . . . . . . . . . . . . . . . .  32
         5.2.7.2.  Multicast . . . . . . . . . . . . . . . . . . . .  37
         5.2.7.3.  Traffic protection  . . . . . . . . . . . . . . .  37
       5.2.8.  Customer specific information . . . . . . . . . . . .  38
         5.2.8.1.  Customer cascaded LANs with provider managed CE .  38
         5.2.8.2.  Customer LANs with provider managed CE  . . . . .  39
         5.2.8.3.  Customer LANs with customer managed CE  . . . . .  39
     5.3.  Using configuration templates . . . . . . . . . . . . . .  39
   6.  Service model usage example . . . . . . . . . . . . . . . . .  43
   7.  Interaction with Other YANG Modules . . . . . . . . . . . . .  47
   8.  YANG Module . . . . . . . . . . . . . . . . . . . . . . . . .  51
   9.  To do list / Open questions / Open issues . . . . . . . . . .  81
   10. Security Considerations . . . . . . . . . . . . . . . . . . .  81
   11. Contributors  . . . . . . . . . . . . . . . . . . . . . . . .  81
   12. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  81
   13. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  81
   14. Normative References  . . . . . . . . . . . . . . . . . . . .  81
   Appendix A.  Example: NETCONF <get> Reply . . . . . . . . . . . .  82
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  82

1.  Introduction

   This document defines a YANG data model for Layer 3 IPVPN service
   configuration.

1.1.  Terminology

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

   o  client

   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

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   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

   Customer Edge (CE) Device: The equipment on the customer side of the
   SP-customer boundary (the customer interface).

   Provider Edge (PE) Device: The equipment on the SP side of the SP-
   customer boundary (the customer interface).

   PE-Based VPNs: The PE devices know that certain traffic is VPN
   traffic.  They forward the traffic (through tunnels) based on the
   destination IP address of the packet, and optionally on based on
   other information in the IP header of the packet.  The PE devices are
   themselves the tunnel endpoints.  The tunnels may make use of various
   encapsulations to send traffic over the SP network (such as, but not
   restricted to, GRE, IP-in-IP, IPsec, or MPLS tunnels).

3.  Layer 3 IP VPN service model

   A Layer 3 IPVPN service is a collection of sites that are authorized
   to exchange traffic between each other over a shared IP
   infrastructure.  This layer 3 VPN service model aims at providing a

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   common understanding on how the corresponding IP VPN service is to be
   deployed over the shared infrastructure.  This service model is
   limited to BGP PE-Based VPNs as described in [RFC4110] and [RFC4364].

4.  Service data model usage

            L3VPN-SVC |
              MODEL   |
                      |
                   +------------------+         +-----+
                   |   Orchestration  | < --- > | OSS |
                   +------------------+         +-----+
                      |            |
              +----------------+   |
              | Config manager |   |
              +----------------+   |
                      |            |
                      | Netconf/CLI ...
                      |            |
        +------------------------------------------------+
                             Network

                           +++++++
                           + AAA +
                           +++++++

   +++++++  Bearer ++++++++             ++++++++       +++++++
   + CEA + ------- + PE A +             + PE B + ----- + CEB +
   +++++++  Cnct   ++++++++             ++++++++       +++++++

   Site A                                       Site B

   The idea of the L3 IPVPN service model is to propose an abstracted
   interface to manage configuration of components of a L3VPN service.
   A typical usage is to use this model as an input for an orchestration
   layer who will be responsible to translate it to orchestrated
   configuration of network elements who will be part of the service.
   The network elements can be routers, but also servers (like AAA), and
   not limited to these examples.  The configuration of network elements
   MAY be done by CLI, or by NetConf/RestConf coupled with specific
   configuration YANG data models (BGP, VRF, BFD ...) or any other way.

   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.

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5.  Design of the Data Model

   The YANG module is divided in two main containers : vpn-svc, sites.

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

   A site is composed of a customer edge router (CE) attached to a
   provider edge router (PE).  The attachment is done through a bearer
   with a connection (transport protocol) on top.  The bearer refers to
   physical properties of the attachment while the connection refers to
   more protocol oriented properties.

   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-l3vpn-svc
      +--rw l3vpn-svc
         +--rw vpn-svc* [name]
         |  +--rw name             string
         |  +--rw id?              uint32
         |  +--rw customer-name?   string
         |  +--rw topology?        identityref
         |  +--rw cloud-access* [cloud-identifier]
         |  |  +--rw cloud-identifier        string
         |  |  +--rw authorized-sites* [site-id]
         |  |  |  +--rw site-id    leafref
         |  |  +--rw denied-sites* [site-id]
         |  |  |  +--rw site-id    leafref
         |  |  +--rw nat-enabled?            boolean
         |  |  +--rw customer-nat-address?   inet:ipv4-address
         |  +--rw multicast
         |     +--rw tree-flavor*           identityref
         |     +--rw rp
         |     |  +--rw ipv4-address?   inet:ipv4-address
         |     |  +--rw ipv6-address?   inet:ipv6-address
         |     +--rw rp-discovery?          identityref
         |     +--rw anycast-rp-location*   string
         +--rw sites* [site-id]
            +--rw template?                        boolean
            +--rw site-id                          string
            +--rw native-vpn?                      leafref
            +--rw site-type?                       identityref
            +--rw apply-template?                  leafref
            +--rw requested-site-start?            yang:date-and-time
            +--rw requested-site-stop?             yang:date-and-time

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            +--rw actual-site-start?               yang:date-and-time
            +--rw actual-site-stop?                yang:date-and-time
            +--rw location
            |  +--rw address?        string
            |  +--rw zip-code?       string
            |  +--rw city?           string
            |  +--rw country-code?   string
            +--rw site-diversity
            |  +--rw type?         enumeration
            |  +--rw site-group*   uint32
            +--rw security
            |  +--rw apply-template?        leafref
            |  +--rw authentication
            |  +--rw encryption
            |  |  +--rw enabled?              boolean
            |  |  +--rw layer?                enumeration
            |  |  +--rw encryption-profile
            |  |     +--rw (profile)?
            |  |        +--:(provider-profile)
            |  |        |  +--rw profile-name?    string
            |  |        +--:(customer-profile)
            |  |           +--rw algorithm?       string
            |  |           +--rw (key-type)?
            |  |                 ...
            |  +--rw access-control-list
            +--rw availability
            |  +--rw availability-type
            |  |  +--rw service-type?   identityref
            |  |  +--rw access-type?    identityref
            |  +--rw loadsharing-type?    identityref
            +--rw attachment
            |  +--rw apply-template?   leafref
            |  +--rw bearer
            |  |  +--rw type?               string
            |  |  +--rw bearer-reference?   string
            |  +--rw connection
            |     +--rw ipv4
            |     |  +--rw address-allocation-type?   identityref
            |     |  +--rw subnet-prefix?             inet:ipv4-prefix
            |     +--rw ipv6
            |     |  +--rw address-allocation-type?   string
            |     |  +--rw subnet-prefix?             inet:ipv6-prefix
            |     +--rw routing-protocols* [type]
            |        +--rw type      identityref
            |        +--rw ospf
            |        |  +--rw address-family*   identityref
            |        |  +--rw area-address?     yang:dotted-quad
            |        |  +--rw metric?           uint16

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            |        |  +--rw sham-link* [target-site]
            |        |     +--rw target-site    leafref
            |        |     +--rw metric?        uint16
            |        +--rw bgp
            |        |  +--rw address-family*   identityref
            |        +--rw static
            |        |  +--rw address-family*   identityref
            |        +--rw rip
            |        |  +--rw address-family*   identityref
            |        +--rw vrrp
            |        |  +--rw address-family*   identityref
            |        +--rw bfd
            |           +--rw bfd-enabled?    boolean
            |           +--rw (holdtime)?
            |              +--:(profile)
            |              |     ...
            |              +--:(fixed)
            |                    ...
            +--rw service
            |  +--rw apply-template?         leafref
            |  +--rw qos
            |  |  +--rw qos-classification-policy
            |  |  |  +--rw rules* [id]
            |  |  |     +--rw id                 uint16
            |  |  |     +--rw match
            |  |  |     |  +--rw ipv4-src-prefix?   inet:ipv4-prefix
            |  |  |     |  +--rw ipv6-src-prefix?   inet:ipv6-prefix
            |  |  |     |  +--rw ipv4-dst-prefix?   inet:ipv4-prefix
            |  |  |     |  +--rw ipv6-dst-prefix?   inet:ipv6-prefix
            |  |  |     |  +--rw l4-src-port?       uint16
            |  |  |     |  +--rw l4-dst-port?       uint16
            |  |  |     |  +--rw l4-protocol?       union
            |  |  |     +--rw target-class-id?   string
            |  |  +--rw std-qos-profile?             string
            |  |  +--rw custom-qos-profile
            |  |     +--rw class* [class-id]
            |  |        +--rw class-id                 string
            |  |        +--rw rate-limit?              uint8
            |  |        +--rw priority-level?          uint8
            |  |        +--rw guaranteed-bw-percent?   uint8
            |  +--rw svc-input-bandwidth?    uint32
            |  +--rw svc-output-bandwidth?   uint32
            |  +--rw svc-mtu?                uint16
            |  +--rw traffic-protection
            |  |  +--rw link-local-protection?    boolean
            |  |  +--rw node-local-protection?    boolean
            |  |  +--rw node-global-protection?   boolean
            |  +--rw mpls

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            |  |  +--rw signalling-type?   enumeration
            |  +--rw multicast
            |     +--rw site-type?   enumeration
            +--rw management
            |  +--rw type?                   identityref
            |  +--rw management-transport?   identityref
            |  +--rw address?                union
            +--rw vpn-policy
            |  +--rw import-policy
            |  |  +--rw vpn*   leafref
            |  +--rw export-policy
            |     +--rw entries* [id]
            |        +--rw id              uint32
            |        +--rw lan-prefixes
            |        |  +--rw ipv4-lan-prefixes* [lan]
            |        |  |  +--rw lan    inet:ipv4-prefix
            |        |  +--rw ipv6-lan-prefixes* [lan]
            |        |     +--rw lan    inet:ipv6-prefix
            |        +--rw lan-tag*        string
            |        +--rw vpn*            leafref
            +--rw maximum-routes
            |  +--rw address-family* [af]
            |     +--rw af                identityref
            |     +--rw maximum-routes?   uint32
            +--rw customer-specific-information
               +--rw name?                      string
               +--rw autonomous-system?         uint32
               +--rw interface?                 string
               +--rw customer-lan-connection* [address]
               |  +--rw address         union
               |  +--rw lan-protocol?   identityref
               +--rw cascaded-lan-prefixes
                  +--rw ipv4-lan-prefixes* [lan]
                  |  +--rw lan         inet:ipv4-prefix
                  |  +--rw lan-tag?    string
                  |  +--rw next-hop?   inet:ipv4-address
                  +--rw ipv6-lan-prefixes* [lan]
                     +--rw lan         inet:ipv6-prefix
                     +--rw lan-tag?    string
                     +--rw next-hop?   inet:ipv6-address

5.1.  VPN service overview

   The vpn-svc top container contains generic information about the VPN
   service.  The name of the vpn-svc refers to an internal reference for
   this VPN service, while customer name refers to a more explicit
   reference to the customer.  An identifier (id) is also present for
   information systems and configuration that requires this information.

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   This identifier is purely internal to the organization responsible
   for the VPN service.  The vpn-svc name and id MUST be unique.

5.1.1.  VPN service topology

   The type of topology of the VPN is required for configuration.
   Current proposal supports : any-to-any, hub and spoke (where hubs can
   exchange traffic), and hub and spoke disjoint (where hubs cannot
   exchange traffic).  New topologies could be added by augmentation.

5.1.1.1.  Route Target allocation

   Layer 3 PE-based VPN is built using route-targets as described in
   [RFC4364].  It is expected management system to allocate
   automatically set of route-targets upon a VPN service creation
   request.  How management system allocates route-targets is out of
   scope of the document but multiple ways could be envisaged as
   described below.

                                    Management system
                     <------------------------------------------------->
                                                 Request RT
                      +-----------------------+  Topo a2a   +----------+
           RestConf   |                       |  ----->     |          |
   User ------------- | Service Orchestration |             |NetworkOSS|
           l3vpn-svc  |                       |  <-----     |          |
             model    +-----------------------+   Response  +----------+
                                                  RT1,RT2

   In the example above, a service orchestration, owning the
   instantiation of this service model, request route-targets to the
   network OSS.  Based on the requested VPN topology, the network OSS
   replies with one or multiple route-targets.  The interface between
   this service orchestration and network OSS is out of scope of this
   document.

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                      +---------------------------+
           RestConf   |                           |
   User ------------- |   Service Orchestration   |
           l3vpn-svc  |                           |
            model     |                           |
                      |  RT pool : 10:1->10:10000 |
                      |  RT pool : 20:50->20:5000 |
                      +---------------------------+

   In the example above, a service orchestration, owning the
   instantiation of this service model, owns one or more pools of route-
   target (filled by service provider) that can be allocated.  Based on
   the requested VPN topology, it will allocate one or multiple route-
   targets from the pool.

   The mechanism displayed above are just examples and SHOULD NOT be
   considered as exhaustive list of solutions.

5.1.1.2.  Any to any

   +------------------------------------------------------------+
   |  VPN1_Site1 ------ PE1               PE2 ------ VPN1_Site2 |
   |                                                            |
   |  VPN1_Site3 ------ PE3               PE4 ------ VPN1_Site4 |
   +------------------------------------------------------------+

               Figure - Any to any VPN topology

   In the any to any topology, all VPN sites can discuss between each
   other without any restriction.  It is expected that the management
   system that owns a any to any IPVPN service request through this
   model, needs to assign and then configure the VRF and route-targets
   on the appropriate PEs.  In case of any to any, in general a single
   route-target is required and every VRF imports and exports this
   route-target.

5.1.1.3.  Hub and Spoke

   +-------------------------------------------------------------+
   |   Hub_Site1 ------ PE1               PE2 ------ Spoke_Site1 |
   |                          +----------------------------------+
   |                          |
   |                          +----------------------------------+
   |   Hub_Site2 ------ PE3               PE4 ------ Spoke_Site2 |
   +-------------------------------------------------------------+

               Figure - Hub and Spoke VPN topology

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   In the hub and spoke topology, all spoke sites can discuss only with
   Hub sites but not between each other.  Hubs can discuss also between
   each other.  It is expected that the management system that owns a
   any to any IPVPN service request through this model, needs to assign
   and then configure the VRF and route-targets on the appropriate PEs.
   In case of hub and spoke, in general a two route-targets are required
   (one route-target for Hub routes, one route-target for spoke routes).
   A Hub VRF, connecting Hub sites, will export Hub routes with Hub
   route-target, and will import Spoke routes through Spoke route-
   target.  It will also import the Hub route-target to permit Hub to
   Hub communication.  A Spoke VRF, connecting Spoke sites, will export
   Spoke routes with Spoke route-target, and will import Hub routes
   through Hub route-target.

   The management system MUST take into account Hub and Spoke
   connections constraints.  For example, if management system decides
   to mesh a spoke site and a hub site on the same PE, it needs to mesh
   connections in different VRFs as displayed in the figure below.

      Hub_Site ------- (VRF_Hub)  PE1
                                 (VRF_Spoke)
                                   /  |
   Spoke_Site1 -------------------+   |
                                      |
   Spoke_Site2 -----------------------+

5.1.1.4.  Hub and Spoke disjoint

   +-------------------------------------------------------------+
   |   Hub_Site1 ------ PE1               PE2 ------ Spoke_Site1 |
   +--------------------------+  +-------------------------------+
                              |  |
   +--------------------------+  +-------------------------------+
   |   Hub_Site2 ------ PE3               PE4 ------ Spoke_Site2 |
   +-------------------------------------------------------------+

             Figure - Hub and Spoke disjoint VPN topology

   In the hub and spoke disjoint topology, all spoke sites can discuss
   only with Hub sites but not between each other.  Hubs cannot discuss
   between each other.  It is expected that the management system that
   owns a any to any IPVPN service request through this model, needs to
   assign and then configure the VRF and route-targets on the
   appropriate PEs.  In case of hub and spoke, in general a two route-
   targets are required (one route-target for Hub routes, one route-
   target for spoke routes).  A Hub VRF, connecting Hub sites, will
   export Hub routes with Hub route-target, and will import Spoke routes

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   through Spoke route-target.  A Spoke VRF, connecting Spoke sites,
   will export Spoke routes with Spoke route-target, and will import Hub
   routes through Hub route-target.

   The management system MUST take into account Hub and Spoke
   connections constraints as in the previous case.

5.1.2.  Cloud access

   The proposed model provides cloud access configuration through the
   cloud-access container.  Internet access can typically be considered
   as cloud access service.  The cloud-access container provides
   parameters for network address translation and authorization rules.

   A cloud identifier is used to reference the target service.  This
   identifier is local to each administration.

   If NAT is required to access to the cloud, the nat-enabled leaf MUST
   be set to true.  A NAT address can be provided in customer-nat-
   address, in case the customer is providing the public IP address for
   the cloud access.  If service provider is providing the NAT address,
   customer-nat-address MAY not be necessary as it can be picked from a
   service provider pool.

   By default, all sites in the IPVPN MUST be authorized to access to
   the cloud.  In case restrictions are required, a user MAY configure
   the authorized-sites and denied-sites list.  The authorization-sites
   defines the list of sites authorized for cloud access.  The denied-
   sites defines the list of sites denied for cloud access.  The model
   supports both "deny all expect" and "accept all expect"
   authorization.

   The "deny all expect" behavior is obtained by filling only the
   authorized-sites.  All the sites listed will be authorized, all
   others will be denied.

   The "accept all expect" behavior is obtained by filling only the
   denied-sites.  All the sites listed will be denied, all others will
   be authorized.

   Defining both denied-sites and authorized-sites MUST be processed as
   "deny all expect", so the denied-sites will have not effect.

   How the restrictions will be configured on network elements is out of
   scope of this document and will be specific to each deployment.

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                     IPVPN
       ++++++++++++++++++++++++++++++++     +++++++++++
       +             Site 3           + --- +  Cloud1 +
       + Site 1                       +     +++++++++++
       +                              +
       + Site 2                       + --- ++++++++++++
       +                              +     + Internet +
       +            Site 4            +     ++++++++++++
       ++++++++++++++++++++++++++++++++
                    |
                ++++++++++
                + Cloud2 +
                ++++++++++

   In the example above, we may configure the global VPN to access
   Internet by creating a cloud-access pointing to the cloud identifier
   for Internet service.  No authorized-sites will be configured as all
   sites are required to access to Internet.  NAT-enabled will be set to
   true and a nat-address will be configured.

   <vpn-svc>
       <name>ZKITYHJ054687</name>
       <id>12456487</id>
       <customer-name>CUSTOMER_1</customer-name>
       <topology>any-to-any</topology>
       <cloud-access>
           <cloud-identifier>51</cloud-identifier>
           <nat-enabled>true</nat-enabled>
           <nat-address>1.1.1.1</nat-address>
       </cloud-access>
   </vpn-svc>

   If Site1 and Site2 requires access to Cloud1, a new cloud-access will
   be created pointing to the cloud identifier of Cloud1.  Authorized
   sites will be filled with reference to Site1 and Site2.

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   <vpn-svc>
       <name>ZKITYHJ054687</name>
       <id>12456487</id>
       <customer-name>CUSTOMER_1</customer-name>
       <topology>any-to-any</topology>
       <cloud-access>
           <cloud-identifier>1111111</cloud-identifier>
           <authorized-sites>
               <site-id>site1</site-id>
               <site-id>site2</site-id>
           </authorized-sites>
       </cloud-access>
   </vpn-svc>

   If all sites except Site1 requires access to Cloud2, a new cloud-
   access will be created pointing to the cloud identifier of Cloud2.
   denied-sites will be filled with reference to Site1.

   <vpn-svc>
       <name>ZKITYHJ054687</name>
       <id>12456487</id>
       <customer-name>CUSTOMER_1</customer-name>
       <topology>any-to-any</topology>
       <cloud-access>
           <cloud-identifier>22222222</cloud-identifier>
           <denied-sites>
               <site-id>site1</site-id>
           </denied-sites>
       </cloud-access>
   </vpn-svc>

5.1.3.  Multicast service

   Multicast in IP VPN is described in [RFC6513].

   If IPVPN supports multicast service, it is expected to provide inputs
   on global multicast parameters.

   The user of this model will need to fill the flavor of trees that
   will be used by customer within the IPVPN (Customer tree).  The
   proposed model supports ASM, SSM and BiDirectional trees (and can be
   augmented).  Multiple flavors of tree can be supported
   simultaneously.

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                          (SSM tree)
    Recv (IGMPv3) -- Site2 ------- PE2
                                              PE1 --- Site1 --- Source1
                                                            \
                                                             -- Source2

                           (ASM tree)
    Recv (IGMPv2) -- Site3 ------- PE3

                           (SSM tree)
    Recv (IGMPv3) -- Site4 ------- PE4
                                   /
    Recv (IGMPv2) -- Site5 --------
                           (ASM tree)

   In case of ASM flavor, this model requires to fill the rp and rp-
   discovery parameters.  The rp-discovery supports the auto-rp, static-
   rp, anycast-rp and bsr-rp modes.

5.2.  Site overview

   The L3VPN service is really attached to the notion of sites.  A site
   is composed of some characteristics :

   o  Unique identifier (site-id) : to uniquely identify the site within
      the overall network infrastructure.  The identifier is a string
      permitting to any encoding for the local administration of the VPN
      service.

   o  Location (location) : site location informations to permit easy
      retrieval on nearest available ressources.

   o  Site constraints (site-diversity) : site-diversity container
      permit to define some constraints for the setup of the site, for
      example : PE disjointness or PoP disjointness.  A site-group
      identifier permit to manage the disjointness.  Two sites with the
      same group and requiring PE disjointness cannot be connected on
      the same PE.

   o  Site availability (site-availability) : permit to define the
      availability service type (single, loadsharing, primary/backup
      scenarios) and also the access-type within the service (single,
      primary, backup ...).

   o  Native VPN (native-vpn) and site-type : reference the vpn-svc, the
      site is belonging to.  The site-type defines the role of the site
      within the native VPN topology (e.g.  Hub, Spoke ...).

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   o  Management (management) : defines the model of management of the
      site, for example : comanaged, customer managed or provider
      managed.

   o  Attachment (attachment) : defines parameters of the attachment of
      the site, especially bearer, connection and service parameters.

   The site configuration is viewed as a global entity, we assume that
   it is mostly the role of the management to split the parameters
   between the different elements within the network.  For example, in
   the case of the attachment configuration, the management system needs
   to split the overall parameters between PE configuration and CE
   configuration.

5.2.1.  Deciding where to connect the site

   The management system will have to decide where to connect the site
   in the provider network (PE, aggregation switch ...).  This decision
   MAY be based on any constraint that are up to the service provider :
   least load, distance ...  The current model proposes some parameters
   that will help the management system to decide where to attach the
   customer site.

5.2.1.1.  Site location

   The location information provided in this model MAY be used by a
   management system to decide the target PE to mesh the site.

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                                        PoP#1 (New York)
                                     +---------+
                                     |   PE1   |
                Site #1 ---...       |   PE2   |
               (Atlantic City)       |   PE3   |
                                     +---------+

                                        PoP#2 (Washington)
                                     +---------+
                                     |   PE4   |
                                     |   PE5   |
                                     |   PE6   |
                                     +---------+

                                        PoP#3 (Philadelphia)
                                     +---------+
                                     |   PE7   |
                Site #2 ---...       |   PE2   |
               (Reston)              |   PE9   |
                                     +---------+

   In the example below, the management system may decide to mesh Site
   #1 on a PE from Philadelphia PoP for distance reason.  It may also
   take in account resources available on PEs to decide the exact target
   PE (least load).  In case of shortest distance PE used, it may also
   decide to mesh Site #2 on Washington PoP.

5.2.1.2.  Site availability

   The site availability defines parameters for the site redundancy.
   The YANG model proposes three models of redundancy (service-type)
   that MAY be extended by augmentation :

   o  single : single homing scenario, no attachment redundancy
      required.

   o  primary-backup : dual homing scenario, one attachment is primary,
      when the attachment goes down, traffic goes to the backup
      attachment.

   o  loadsharing : multihoming scenario, both attachment are used at
      the same time.  How loadsharing is done is not part of service-
      type.

   The site availability also defines access-type which defines the role
   of the site in the availability system.  The YANG model proposes four
   models of access-type :

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   o  single-access : used to indicate the single access function.  Used
      for single-homed sites and coupled with "single" service-type.

   o  primary-access : used to indicate the primary access in a primary-
      backup service-type.

   o  backup-access : used to indicate the backup access in a primary-
      backup service-type.

   o  loadsharing-access : used to indicate any access in a loadsharing
      service-type.

   The figure below describes how site availability attributes can be
   used.

   Hub#1 LAN                                        Hub#2 LAN
     |      primary-backup           loadsharing        |
     |      primary-access           loadsharing-access |
     |--- CE1 ------- PE1         PE3 --------- CE3 --- |
     |                                                  |
     |                                                  |
     |--- CE2 ------- PE2         PE4 --------- CE4 --- |
     |       primary-backup           loadsharing       |
             backup-access            loadsharing-access

                             PE5
                              | single
                              | single-access
                              |
                             CE5
                              |
                         Spoke#1 site

   In case of loadsharing, the YANG model proposes to define the
   loadsharing policy using loadsharing-type.  The model proposes the
   following types that could be augmented.  These option MAY be used on
   any remote sites (single, primary-backup ...) facing a loadsharing
   site.

   o  loadsharing-ibgp : loadbalancing will be done between multiple
      received iBGP paths.

   o  loadsharing-eibgp : loadbalancing will be done between multiple
      received iBGP paths or eBGP paths : typical application is when a
      remote site is connected on the same PE than the hub requiring
      loadsharing.

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   Considering the diagram above, to enable loadsharing for Hub#2 sites,
   Hub#1 sites and Spoke#1 site can be configured with loadsharing-ibgp
   as loadsharing-type.  If a Spoke#2 site was connected also on PE4,
   Spoke#2 site may be configured with loadsharing-eibgp as loadsharing-
   type.

                               Hub#2 LAN
              loadsharing        |
              loadsharing-access |
           PE3 --------- CE3 --- |
                                 |
                                 |
           PE4 --------- CE4 --- |
           |   loadsharing       |
           |   loadsharing-access
           |
           | single
           | single-access
           | loadsharing-eibgp
           |
           CE6
           |
       Spoke#2 site

   The site availability will have an impact on site meshing location,
   as dual homing may require meshing at least on different network
   elements (see next section).

5.2.1.3.  Site diversity

   The site diversity defines what is the acceptable fate sharing level
   in case multiple sites for a single VPN must be provisioned in a
   common location.  The site diversity introduces the notion of site-
   group.  Sites belonging to the same site-group cannot share the same
   fate.  We propose to introduce two constraints :

      PoP diverse : site belonging to the same site-group MUST be
      provisioned on different PoPs.

      PE diverse : site belonging to the same site-group MUST be
      provisioned on different PE routers.

   How these diversity constraints are applied is out of scope of the
   document.  As an example, the management system receiving the request
   for diversity, MAY exchange information with some OSS components to
   define the best target PEs based on location and ressource
   availability.

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   Consider a dual homed hub site, it is desirable for redundancy to
   provision the two VPN access connections on two different PEs or two
   different PoPs.

                                        PoP#1
                                     +---------+
                                     |   PE1   |
       Hub_Site_primary ------       |   PE2   |
                                     |   PE3   |
                                     +---------+

                                        PoP#2
                                     +---------+
                                     |   PE4   |
       Hub_Site_backup -------       |   PE5   |
                                     |   PE6   |
                                     +---------+

   In a PoP diverse scenario, the management system may decide to mesh
   Hub_Site_primary on any PE of PoP#1 and Hub_Site_backup on any PE of
   PoP#2.  In a PE diverse scenario, if the management system decides to
   mesh Hub_Site_primary on PE1, it is require to mesh Hub_Site_backup
   on any PE different from PE1.

   Site diversity is not limited to multihoming scenarios.  If a company
   has multiple small branch offices (single homed) that requires to be
   connected in the same location, it is desirable to dispatch the
   attachment on multiple PEs.  So in case of PE crash, only some
   offices will be impacted.

                                        PoP#1
                                     +---------+
                                     |   PE1   |
               Office#1 ---...       |   PE2   |
               Office#2 ---...       |   PE3   |
               Office#3 ---...       |   PE4   |
               Office#...--...       +---------+
               Office#100--...

   In the figure above, it may be good to mesh 25 offices on each PE of
   PoP#1 to prevent concentration of two many customer offices on common
   network elements.

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5.2.1.4.  Route Distinguisher and VRF allocation

   Route distinguisher is also a critical parameter of PE-based L3VPN as
   described in [RFC4364] that will permit to distinguish common
   addressing plans in different VPNs.  As for Route-targets, it is
   expected management system to allocate a VRF on the target PE and a
   route-distinguisher for this VRF.

   If a VRF exists on the target PE, and the VRF fulfils the
   connectivity constraints for the site, there is no need to recreate
   another VRF and the site MAY be meshed within this existing VRF.  How
   the management system checks that an existing VRF fulfils the
   connectivity constraints for a site is out of scope of this document.

   If no VRF exists on the target PE, filling the site constraints, the
   management system will have to initiate a new VRF creation on the
   target PE and will have to allocate a new route distinguisher for
   this new VRF.

   The management system MAY apply a per-VPN or per-VRF allocation
   policy for the route-distinguisher depending of the service provider
   policy.  In a per-VPN allocation policy, all VRFs (dispatched on
   multiple PEs) within a VPN will share the same route distinguisher
   value.  In a per-VRF model, all VRFs will always have a unique route-
   distinguisher value.  Some other allocation policies are also
   possible, and this document does not restrict the allocation policies
   to be used.

   Allocation of route-distinguisher MAY be done in the same way as the
   route-targets.  The example provided in Section 5.1.1.1 could be
   reused.

   Note that a service provider MAY decide to configure target PE for
   automated allocation of route distinguisher.  In this case, there
   will be no need for any backend system to allocate a route-
   distinguisher value.

5.2.2.  VPN policy

   The VPN policy defines the route exchange between multiple VPNs.  A
   vpn-policy configuration is not required if there is no inter VPN
   relations.  Indeed the VPN policy already exists from the topology of
   the VPN, and the management system using this service model MUST
   derive the VRF configuration from the VPN topology.  The vpn-policy
   container only defines relations with VPNs that are not the native
   vpn.  In case, a vpn-policy is defined, the management system will
   built the route-target policy configuration from a combination of
   both the vpn-policy and the vpn-topology.

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   +--------------------------------------------------------------+
   |  VPN1_Site1 ------ PE1               PE2 ------ VPN1_Site2   |
   +--------------------------------------------------------------+

   +--------------------------------------------------------------+
   |  VPN2_Site1 ------ PE3               PE4 ------ VPN2_Site2   |
   +----------------------------------+                           |
                                      |                           |
   +------------------------------------------------------------+ |
   |  VPN3_Site1 ------ PE5           |   PE6 ------ VPN3_Site2 | |
   +------------------------------------------------------------+ |
                                      |                           |
                                      +---------------------------+

   Let us consider two existing vpn service VPN1 and VPN2 with a any-to-
   any topology.  When the vpn services are provisioned a route-target
   value will be affected by the OSS of the service provider for these
   VPNs.  Let's call RT1 the route-target of VPN1,and RT2 the route-
   target of VPN2.  Now we consider a new VPN service VPN3 (any to any)
   that must be provisioned, RT3 will be allocated by the OSS for proper
   configuration on network elements.

   Consider a site#1 in VPN3 that must communicate only in VPN3, in this
   case, there is no need to specify any vpn-policy for site#1, as
   site#1 will be provisioned using the native-vpn policy which is any-
   to-any in VPN3.  VRF on PE5 for VPN3 will be so provisioned by the
   management system using RT3 value as import and export value.

   Consider a site#2 in VPN3 that must communicate in VPN3, and a
   specific LAN LAN1 must communicate with VPN2, in this case, we need
   to define for site#2 a vpn-policy that imports VPN2 and exports LAN1
   to VPN2.  VRF on PE6 for VPN3 will be so provisioned by the
   management system using RT3 value as import and RT3 as export value
   plus RT2 for LAN1 prefix.

5.2.3.  Security

   Security container defines customer specific security parameters for
   the site.  This section will more be detailled in future revision.

5.2.3.1.  Encryption

   Encryption can be requested on the connection.  It may be performed
   at layer 2 or layer 3 by selecting the appropriate enumeration in
   "layer" leaf.  The encryption profile can be a service provider
   defined template or customer specific.

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5.2.4.  Management

   The model proposes three types of common management options :

   o  comanaged : the CE router is managed by the provider and also by
      the customer.

   o  provider-managed : the CE router is managed only by the provider.

   o  customer-managed : the CE router is managed only by the customer.

   Based on the management model, different security options MAY be
   derived.

   In case of "provider-managed" or "comanaged", the model proposes some
   option to define the management transport protocol (IPv4 or IPv6) and
   the associated management address.

5.2.5.  Attachment

   The attachment defines how the service is connected on the network
   and is splitted in three class of parameters :

   o  bearer : defines physical parameters of the attachment.

   o  connection : defines protocol parameters of the attachment
      (transport layer and routing protocols).

5.2.5.1.  Bearer

   TBD.

5.2.5.2.  Connection

   The connection defines the protocol parameters of the attachment
   (IPv4 and IPv6) as well as routing.

5.2.5.2.1.  IP addressing

   IP subnet can be configured for either transport protocols.  For a
   dual stack connection, two subnets will be provided, one for each
   transport layer.

   The address-allocation-type will help in defining how the address
   allocation MUST be done.  The current model proposes three ways of IP
   address allocation :

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   o  pe-dhcp : the PE router will provide DHCP service for CE router,
      this is applicable to both IPv4 and IPv6 addressing.

   o  static-address : Addresses will be assigned manually on both
      sides, this is applicable to both IPv4 and IPv6 addressing.

   o  slaac : enables stateless address autoconfiguration ([RFC4862]).
      This is applicable only for IPv6.

5.2.5.2.2.  Routing protocols

   Routing-protocol defines which routing protocol must be activated
   between the provider edge and the customer.  The current model
   support : bgp, rip, rip-ng, ospf, static, direct, vrrp.

                               Rtg protocol
       192.0.2.0/24 ----- CE ----------------- PE1

   If the CE is comanaged or provider managed, the management system
   will be required to configure the routing protocol on both side on
   the connnection.

                                     |  L3VPN SVC model
                                     |
                              +------------+
                              + Mgt system +
                              +------------+
                               /          \
                              /            \ Routing protocol config
                             /              \    (CLI, Netconf ...)
                            /  Rtg protocol  \
       192.0.2.0/24 ----- CE ----------------- PE1

          Routing protocol config - provider managed or comanaged CE

   If the CE is customer managed, the management system will be required
   to configure the routing protocol only the PE router.

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                                     |  L3VPN SVC model
                                     |
                              +------------+
                              + Mgt system +
                              +------------+
                                          \
                                           \ Routing protocol config
                                            \    (CLI, Netconf ...)
                               Rtg protocol  \
       192.0.2.0/24 ----- CE ----------------- PE1

            Routing protocol config - customer managed CE

5.2.5.2.2.1.  Dual stack handling

   All routing protocol types support dual stack by using address-family
   leaf-list.

   Example of Dual stack using the same routing protocol :

   <routing-protocol>
       <type>static</type>
       <static>
           <address-family>ipv4-unicast</address-family>
           <address-family>ipv6-unicast</address-family>
       </static>
   </routing-protocol>

   Example of Dual stack using two different routing protocols :

   <routing-protocol>
       <type>rip</type>
       <rip>
           <address-family>ipv4-unicast</address-family>
       </rip>
   </routing-protocol>
   <routing-protocol>
       <type>ospf</type>
       <ospf>
           <address-family>ipv6-unicast</address-family>
       </ospf>
   </routing-protocol>

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5.2.5.2.2.2.  Direct LAN connection onto SP network

   Routing-protocol "direct" SHOULD be used when a customer LAN is
   directly connected to the provider network and must be advertised in
   the IPVPN.

           LAN attached directly to provider network :

           192.0.2.0/24 ----- PE1

5.2.5.2.2.3.  Direct LAN connection onto SP network with redundancy

   Routing-protocol "vrrp" SHOULD be used when a customer LAN is
   directly connected to the provider network and must be advertised in
   the IPVPN and LAN redundancy is expected.

         LAN attached directly to provider network with LAN redundancy:

           192.0.2.0/24 ------ PE1
                          |
                          +-- PE2

5.2.5.2.2.4.  Static routing

   Routing-protocol "static" MAY be used when a customer LAN is
   connected to the provider network through a CE router and must be
   advertised in the IPVPN.

                                   Static rtg
           192.0.2.0/24 ------ CE -------------- PE
                               |                |
                               |      Static route 192.0.2.0/24 nh CE
               Static route 0.0.0.0/0 nh PE

5.2.5.2.2.5.  RIP routing

   Routing-protocol "rip" MAY be used when a customer LAN is connected
   to the provider network through a CE router and must be advertised in
   the IPVPN.

   In case of dual stack, the management system will be responsible to
   configure rip (including right version number) and rip-ng instances
   on network elements.

                                   RIP rtg
           192.0.2.0/24 ------ CE -------------- PE

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5.2.5.2.2.6.  OSPF routing

   Routing-protocol "ospf" MAY be used when a customer LAN is connected
   to the provider network through a CE router and must be advertised in
   the IPVPN.

   It can be used to extend an existing OSPF network and interconnect
   different areas.  See [RFC4577] for more details.

                             +---------------------+
                             |                     |
                     OSPF    |                     | OSPF
                     area 1  |                     | area 2
    (OSPF                    |                     |          (OSPF
    area 1) --- CE ---------- PE               PE ----- CE --- area 2)
                             |                     |
                             +---------------------+

   The model also proposes an option to create an OSPF sham-link between
   two sites sharing the same area and having a backdoor link.  The
   sham-link is created by referencing the target site sharing the same
   OSPF area.  The management system will be responsible to check if
   there is already a shamlink configured for this VPN and area between
   the same pair of PEs.  If there is no existing shamlink, the
   management system will provision it, this shamlink MAY be reused by
   other sites.

                           +------------------------+
                           |                        |
                           |                        |
                           |   PE (--shamlink--)PE  |
                           |    |                |  |
                           +----|----------------|--+
                                | OSPF area1     | OSPF area 1
                                |                |
                                CE1             CE2
                                |                |
                           (OSPF area1)       (OSPF area1)
                                |                |
                                +----------------+

   Regarding Dual stack support, user MAY decide to fill both IPv4 and
   IPv6 address families, if both protocols SHOULD be routed through
   OSPF.  As OSPF is using two different protocol for IPv4 and IPv6, the
   management system will need to configure both ospf version 2 and
   version 3 on the PE-CE link.

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   Example of OSPF routing parameters in service model.

   <routing-protocol>
       <type>ospf</type>
       <ospf>
           <area-address>1.1.1.1</area-address>
           <address-family>ipv4-unicast</address-family>
           <address-family>ipv6-unicast</address-family>
       </ospf>
   </routing-protocol>

   Example of PE configuration done by management system :

   router ospf 10
    area 0.0.0.0
     interface Ethernet0/0
   !
   router ospfv3 10
    area 0.0.0.0
     interface Ethernet0/0
    !

5.2.5.2.2.7.  BGP routing

   Routing-protocol "bgp" MAY be used when a customer LAN is connected
   to the provider network through a CE router and must be advertised in
   the IPVPN.

                                   BGP rtg
           10.0.0.0/24 ------ CE -------------- PE

   The AS numbers, peerings addressing will be derived from connection
   parameters or customer-specific-information as well as internal
   knowledge of SP.

   In case of dual stack access, user MAY request BGP routing for both
   IPv4 and IPv6 by filling both address-families.  It will be up to SP
   and management system to decide how to decline the configuration (two
   BGP sessions, single, multisession ...).

   The service configuration below actives BGP on PE-CE link for both
   IPv4 and IPv6.

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   <routing-protocol>
       <type>bgp</type>
       <bgp>
           <address-family>ipv4-unicast</address-family>
           <address-family>ipv6-unicast</address-family>
       <bgp>
   </routing-protocol>

   This service configuration can be derived by management system into
   multiple flavors depending on SP flavor.

   Example #1 of PE configuration done by management system
   (single session IPv4 transport):

   router bgp 100
    neighbor 203.0.113.2 remote-as 65000
    address-family ipv4 vrf Cust1
       neighbor 203.0.113.2 activate
    address-family ipv6 vrf Cust1
       neighbor 203.0.113.2 activate
       neighbor 203.0.113.2 route-map SET-NH-IPV6 out

   Example #2 of PE configuration done
   by management system (two sessions):

   router bgp 100
    neighbor 203.0.113.2 remote-as 65000
    neighbor 2001::2 remote-as 65000
    address-family ipv4 vrf Cust1
       neighbor 203.0.113.2 activate
    address-family ipv6 vrf Cust1
       neighbor 2001::2 activate

   Example #3 of PE configuration done
   by management system (multisession):

   router bgp 100
    neighbor 203.0.113.2 remote-as 65000
    neighbor 203.0.113.2 multisession per-af
    address-family ipv4 vrf Cust1
       neighbor 203.0.113.2 activate
    address-family ipv6 vrf Cust1
       neighbor 203.0.113.2 activate
       neighbor 203.0.113.2 route-map SET-NH-IPV6 out

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5.2.6.  MPLS

   In case of Carrier Supporting Carrier (CsC), a customer MAY want to
   build MPLS service using an IPVPN as transport layer.

           LAN customer1
               |
               |
              CE1
               |
               | -------------
            (vrf_cust1)
             CE1_ISP1
               |                 ISP1 PoP
               | MPLS link
               | -------------
               |
            (vrf ISP1)
              PE1

             (...)               Provider backbone

              PE2
             (vrf ISP1)
               |
               | ------------
               |
               | MPLS link
               |                 ISP1 PoP
              CE2_ISP1
              (vrf_cust1)
               |-------------
               |
              CE2
               |
            Lan customer1

   In the figure above, ISP1 resells IPVPN service but has no transport
   infrastructure between its PoPs.  ISP1 uses an IPVPN as transport
   infrastructure (belonging to another provider) between its PoPs.  The
   link between CE1_ISP1/PE1 and CE2_ISP1/PE2 MUST so be MPLS enabled.

   In the proposed model, LDP or BGP can be used as MPLS signalling
   protocol.  In case of LDP, an IGP routing protocol MUST also be

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   activated.  In case of BGP signalling, BGP MUST also be configured as
   routing-protocol.

5.2.7.  Service

   The service defines service parameters associated with the site.

5.2.7.1.  QoS

   The model proposes to define QoS parameters in an abstracted way :

   o  qos-classification-policy : define a set of ordered rules to
      classify customer traffic.

   o  std-qos-profile : provider standard outgoing QoS profile to be
      applied.  This is a reference to a well known profile in Service
      provider administration.

   o  custom-qos-profile : defines customer specific profiles.

5.2.7.1.1.  QoS classification

   QoS classification rules are handled by qos-classification-policy.
   The qos-classification-policy is an ordered list of rules that match
   a flow and set the appropriate target class of service (target-class-
   id).  The match criterions provide a basic infrastructure for
   defining flows : layer 3 source and destination address, layer 4
   ports, layer 4 protocol.

   Where the classification is done depends on the SP implementation of
   the service, but classification concerns the flow coming from the
   customer site and entering the network.

                                  Provider network
                             +-----------------------+
      192.0.2.0/24
   198.51.100.0/24 ---- CE --------- PE

     Traffic flow
    ---------->

   In the figure above, the management system can decide :

   o  if the CE is customer managed, to implement the classification
      rule in the ingress direction on the PE interface.

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   o  if the CE is provider managed, to implement the classification
      rule in the ingress direction on the CE interface connected to
      customer LAN.

   The figure below describes a sample service description of qos-
   classification for a site :

   <service>
       <qos>
           <qos-classification-policy>
               <rules>
                   <id>1</id>
                   <match>
                       <ipv4-src-prefix>192.0.2.0/24</ipv4-src-prefix>
                       <ipv4-dst-prefix>1.1.1.1/32</ipv4-dst-prefix>
                       <l4-dst-port>80</l4-dst-port>
                       <l4-protocol>tcp</l4-protocol>
                   </match>
                   <target-class-id>DATA2</target-class-id>
               </rules>
               <rules>
                   <id>2</id>
                   <match>
                       <ipv4-src-prefix>192.0.2.0/24</ipv4-src-prefix>
                       <ipv4-dst-prefix>1.1.1.1/32</ipv4-dst-prefix>
                       <l4-dst-port>21</l4-dst-port>
                       <l4-protocol>tcp</l4-protocol>
                   </match>
                   <target-class-id>DATA2</target-class-id>
               </rules>
               <rules>
                   <id>3</id>
                   <target-class-id>DATA1</target-class-id>
               </rules>
           </qos-classification-policy>
       </qos>
   </service>

   In the example above :

   o  HTTP traffic from 192.0.2.0/24 LAN destinated to 1.1.1.1/32 will
      be classified in DATA2.

   o  FTP traffic from 192.0.2.0/24 LAN destinated to 1.1.1.1/32 will be
      classified in DATA2.

   o  All other traffic will be classified in DATA1.

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   The order of rules is really important.  The management system
   responsible for translating those rules in network element
   configuration MUST keep the same processing order in element
   configuration.  The order of rule is defined by the "id" leaf.  The
   lowest "id" MUST be processed first.

5.2.7.1.2.  QoS profile

   std-qos-profile and custom-qos-profile define output QoS profiles to
   be used between PE and CE.

                                  Provider network
                             +-----------------------+
   192.0.2.0/24
   198.51.100.0/24 ---- CE --------- PE
                           \       /
                          qos-profile

   std-qos-profile and custom-qos-profile cannot be used at the same
   time.  If both are present, the management system SHOULD keep only
   the custom-qos-profile.

   A custom-qos-profile is defined as a list of class of services and
   associated properties.  The properties are :

   o  rate-limit : used to rate-limit the class of service.  The value
      is expressed as a percentage of the global service bandwidth.

   o  priority-level : used to define priorities between class of
      services.  The value of the priority to be used is dependant of
      each administration.  The higher the priority-level is, the higher
      the priority of the class will be.  Priority-level is used to
      define strict priority queueing.  A priority-level 250 class will
      be served before a priority-level 100 class until there is no more
      packet to process or until rate-limit does not allow anymore
      packets from the higher priority class.

   o  guaranteed-bw-percent : used to define a guaranteed amount of
      bandwidth for the class of service.  It is expressed as a
      percentage.  The guaranteed-bw-percent uses available bandwidth at
      the priority-level of the class.

   Example of service configuration using a standard qos profile :

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   <sites>
       <site-id>1245HRTFGJGJ154654</site-id>
       <native-vpn>VPN1</native-vpn>
       <site-type>any-to-any-site</site-type>
       <service>
           <svc-input-bandwidth>100000000</svc-input-bandwidth>
           <svc-output-bandwidth>100000000</svc-output-bandwidth>
           <qos>
               <std-qos-profile>PLATINUM</std-qos-profile>
           </qos>
       </service>
   </sites>
   <sites>
       <site-id>555555AAAA2344</site-id>
       <native-vpn>VPN1</native-vpn>
       <site-type>any-to-any-site</site-type>
       <service>
           <svc-input-bandwidth>2000000</svc-input-bandwidth>
           <svc-output-bandwidth>2000000</svc-output-bandwidth>
           <qos>
               <std-qos-profile>GOLD</std-qos-profile>
           </qos>
       </service>
   </sites>

   Example of service configuration using a custom qos profile :

   <sites>
       <site-id>Site1</site-id>
       <native-vpn>VPN1</native-vpn>
       <site-type>any-to-any-site</site-type>
       <service>
           <svc-input-bandwidth>100000000</svc-input-bandwidth>
           <svc-output-bandwidth>100000000</svc-output-bandwidth>
           <qos>
               <custom-qos-profile>
                   <class>
                       <class-id>REAL_TIME</class-id>
                       <rate-limit>10</rate-limit>
                       <priority-level>10</priority-level>
                   </class>
                   <class>
                       <class-id>DATA</class-id>
                       <priority-level>5</priority-level>
                   </class>
               </custom-qos-profile>
           </qos>

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       </service>
   </sites>
   <sites>
       <site-id>Site2</site-id>
       <native-vpn>VPN1</native-vpn>
       <site-type>any-to-any-site</site-type>
       <service>
           <svc-input-bandwidth>2000000</svc-input-bandwidth>
           <svc-output-bandwidth>2000000</svc-output-bandwidth>
           <qos>
               <custom-qos-profile>
                   <class>
                     <class-id>REAL_TIME</class-id>
                     <rate-limit>30</rate-limit>
                     <priority-level>10</priority-level>
                   </class>
                   <class>
                     <class-id>DATA1</class-id>
                     <priority-level>5</priority-level>
                     <guaranteed-bw-percent>80</guaranteed-bw-percent>
                   </class>
                   <class>
                     <class-id>DATA2</class-id>
                     <priority-level>5</priority-level>
                     <guaranteed-bw-percent>20</guaranteed-bw-percent>
                   </class>
               </custom-qos-profile>
           </qos>
       </service>
   </sites>

   The custom-qos-profile for site1 defines that traffic from REAL_TIME
   class will have a higher priority than traffic from DATA class.  The
   REAL_TIME traffic will be rate-limit to 10% of the service bandwidth
   (10% of 100Mbps = 10Mbps) to let some place for DATA traffic.

   The custom-qos-profile for site2 defines that traffic from REAL_TIME
   class will have a higher priority than traffic from data traffic.
   Data traffic will be splitted in two class of service DATA1 and DATA2
   that will share bandwidth between them according to the percentage of
   guaranteed-bw-percent.  The maximum of percentage to be used is not
   limited by this model but MUST be limited by the management system
   according to the policies authorized by the service provider.  The
   REAL_TIME traffic will be rate-limit to 30% of the service bandwidth
   (30% of 100Mbps = 30Mbps) to let some place for data traffic.  In
   case of congestion of the access, the REAL_TIME traffic can go up to
   30Mbps (Let's assume that 20Mbps only are consumed).  The DATA1 and

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   DATA2 will share remaining bandwidth (80Mbps) according to their
   percentage.  So DATA1 will be served with at least 64Mbps of
   bandwidth.

5.2.7.2.  Multicast

   The multicast section defines the type of site in the customer
   multicast topology : source, receiver, or both.  These parameters
   will help management system to optimize the multicast service.

5.2.7.3.  Traffic protection

   The service model supports the ability to protect traffic from or to
   a site.

       Site#1                            Site#2
   CE1 ----- PE1 -- P1            P3 -- PE3 ---- CE3
    |                              |             |
    |                              |             |
   CE2 ----- PE2 -- P2            P4 -- PE4 ---- CE4
             /
            /
   CE5 ----+
      Site#3

   In the figure above, we consider an IPVPN service with three sites
   including two dual homed sites (site#1 and #2).  For dual homed
   sites, we consider PE1-CE1 and PE3-CE3 as primary, and
   PE2-CE2,PE4-CE4 as backup for the example (even if protection also
   applies to loadsharing scenarios.)

   In order to protect Site#2 for a PE-CE link failure, a service
   provider MAY configure link-local-protection on the primary access of
   site#2 (PE3-CE3).  In such case, if we consider traffic coming from a
   remote site (site#1 or site#3), primary path is to use PE3 as egress
   PE.  PE3 has preprogrammed a backup forwarding entry pointing to
   backup path (through PE4-CE4) for all prefixes going through PE3-CE3
   link.  How backup path is computed is out of scope of the document.
   When PE3-CE3 link fails, traffic is still received by PE3 but PE3
   switch automatically traffic to the backup entry, path will so be
   PE1-P1-(...)-P3-PE3-PE4-CE4 until remote PEs reconverge and use PE4
   as egress PE.

   In order to protect Site#2 for a egress PE node failure, a service
   provider may configure node-local-protection on the primary access of

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   site#2 (PE3-CE3).  This protection flavor is so called egress PE node
   protection.  In such case, if we consider traffic coming from a
   remote site (site#1 or site#3), primary path is to use PE3 as egress
   PE.  P3 has preprogrammed a backup forwarding entry pointing to
   backup path.  How backup path is computed is out of scope of the
   document.  When PE3 node fails, traffic is still received by P3 but
   P3 switch automatically traffic to the backup entry, path will so be
   PE1-P1-(...)-P3-P4-PE4-CE4 until remote PEs reconverge and use PE4 as
   egress PE.

   In order to protect Site#2 for a egress PE node failure, another
   flavor of protection can be used, a service provider MAY configure
   node-global-protection on all remote sites.  This protection flavor
   is generally called PIC Edge (Prefix Independent Convergence for
   Edge).  In such case, if we consider traffic coming from a remote
   site (site#1 or site#3), primary path is to use PE3 as egress PE.
   All remote PEs (PE1,PE2) have preprogrammed a backup forwarding entry
   pointing to backup path (through PE4).  How backup path is computed
   is out of scope of the document.  When PE3 node fails, remote PEs
   detect through IGP convergence that PE3 is no more reachable and
   decide to switch automatically traffic to the backup entry, path will
   so be PE1-P1-(...)-P4-PE4-CE4.  In this case, as BGP convergence is
   involved, there is no other need of reconvergence.

5.2.8.  Customer specific information

   Customer specific informations are used to store informations owned
   by customers.  The customer may have some LANs directly connected to
   CE routers managed by Service providers.  In this case, customer
   needs to allocate IP addresses from its LAN addressing plan for the
   CE router.  This is the purpose of the customer-lan-connection list
   which provides information about addresses allocated from each
   customer LAN connected to the CE router.

   In case, provider needs to route some LAN that are cascaded behind
   those connected LANs, cascaded-lan-prefixes can be used.  In this
   version of the document, static routing is assumed between CE and
   customer LANs.

5.2.8.1.  Customer cascaded LANs with provider managed CE

      192.0.2.0/24 ---- CustFW1 ---- 203.0.113.0/24 --- CE1 ----- PE1
                       /
   198.51.100.0/24 ----

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   In the example above, CE1 owned by service provider is attached to
   203.0.113.0/24 LAN of the customer.  Customer allocated 192.0.2.254
   for CE1, this information will have to be reported as a customer-lan-
   connection in the service model.  Customer also have two LANs
   cascaded behind a firewall (192.0.2.0/24 and 198.51.100.0/24), those
   LANs MUST be routed within the IPVPN.  cascaded-lan-prefixes MUST be
   used to fill those informations.  The IP address of the firewall MUST
   be filled as nexthop of those LANs.

5.2.8.2.  Customer LANs with provider managed CE

    192.0.2.0/24 ----  CE1 ----- PE1
                       /
   198.51.100.0/24 ----

   In the example above, CE1 owned by service provider is attached to
   203.0.113.0/24 LAN of the customer.  Customer allocated 192.0.2.254
   and 198.51.100.254 for CE1, this information will have to be reported
   as a customer-lan-connection in the service model.

5.2.8.3.  Customer LANs with customer managed CE

   192.0.2.0/24 ----  CE1 ----- PE1
                       /
   198.51.100.0/24 ----

   In the example above, CE1 owned by customer is attached to
   203.0.113.0/24 LAN.  The service provider only have to deal with
   routing with customer CE, the routing-protocol information on the
   connection will define this.

5.3.  Using configuration templates

   The proposed model supports the creation and application of
   configuration templates for sites.

   A template can be configured by creating a new site with the template
   leaf equal to true.  This means that the site is not a real site and
   its just a configuration template.

   Multiple template sites can be configured.  Templates can be applied
   at multiple levels referenced by apply-template leaf.  The apply-
   template references the site-id of the template to be called.  The
   location of the apply-template within the sites hierarchy defines
   which parameters must be inherited.  For example, if apply-template

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   is done on service container of a site, only service container
   parameters (and childs) from the template will be applied.

   Apply-template cannot be used within a template.

   <sites>
    <site-id>Template-VoiceCoS-Cust1</site-id>
     <template>true</template>
     <service>
      <qos>
       <custom-qos-profile>
        <class>
         <class-id>REAL_TIME</class-id>
         <rate-limit>30</rate-limit>
         <priority-level>10</priority-level>
        </class>
        <class>
         <class-id>DATA1</class-id>
         <priority-level>5</priority-level>
         <guaranteed-bw-percent>80</guaranteed-bw-percent>
        </class>
        <class>
         <class-id>DATA2</class-id>
         <priority-level>5</priority-level>
         <guaranteed-bw-percent>20</guaranteed-bw-percent>
        </class>
      </custom-qos-profile>
     </qos>
    </service>
   </sites>

   <sites>
       <site-id>Template-VPNsite-Customer1</site-id>
       <native-vpn>VPN1</native-vpn>
       <site-type>any-to-any-site</site-type>
       <template>true</template>
       <service>
           <qos>
               <std-qos-profile>PLATINUM</std-qos-profile>
           </qos>
       </service>
       <attachment>
           <connection>
               <routing-protocol>
                   <name>static</name>
                   <type>static</type>
               </routing-protocol>

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           </connection>
       </attachment>
       <vpn-policy>
           <import-policy>
               <vpn>Service_VPN1</vpn>
           </import-policy>
           <export-policy>
               <entries>
                   <lan-tag>VOICE</lan-tag>
                   <vpn>Service_VPN1</vpn>
               </entries>
           </export-policy>
       </vpn-policy>
   </sites>

   Template sites permit to define configuration blocks that will be
   inherited by one or multiple sites in order to speed up
   configuration.  For example, if all the sites of an IPVPN service
   have the almost same configuration (routing-protocol, qos, management
   ...), a template can be created and each site of the VPN will
   reference the template.  If a site has some particular parameters,
   specific parameters within the site MUST always override parameters
   derived from template.

   The example above defines two site templates :

   o  Template-VPNsite-Customer1 that will be used to configure all the
      VPN sites for customer 1.

   o  Template-VoiceCoS-Cust1 that will be used to configure some
      special CoS policy on some specific accesses of the VPN.

   In the example below, all sites of VPN1 are inheriting basic
   configuration from template Template-VPNsite-Customer1.  Some
   specific parameters like svc-input-bandwidth are also defined for
   each site.  For Site 4 and 5 , specific QoS parameters are required,
   a new template Template-VoiceCoS-Cust1 is applied at service level
   for these two sites, overriding the service parameters from the
   Template-VPNsite-Customer1 template.

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   <sites>
       <site-id>Site1</site-id>
       <apply-template>Template-VPNsite-Customer1</apply-template>
       <service>
           <svc-input-bandwidth>5000000</svc-input-bandwidth>
           <svc-output-bandwidth>5000000</svc-output-bandwidth>
       </service>
   </sites>
   <sites>
       <site-id>Site2</site-id>
       <apply-template>Template-VPNsite-Customer1</apply-template>
           <service>
           <svc-input-bandwidth>20000000</svc-input-bandwidth>
           <svc-output-bandwidth>20000000</svc-output-bandwidth>
       </service>
   </sites>
   <sites>
       <site-id>Site3</site-id>
       <apply-template>Template-VPNsite-Customer1</apply-template>
       <service>
           <svc-input-bandwidth>30000000</svc-input-bandwidth>
           <svc-output-bandwidth>30000000</svc-output-bandwidth>
       </service>
   </sites>

   <sites>
       <site-id>Site4</site-id>
       <apply-template>Template-VPNsite-Customer1</apply-template>
       <service>
           <apply-template>Template-VoiceCoS-Cust1</apply-template>
           <svc-input-bandwidth>100000000</svc-input-bandwidth>
           <svc-output-bandwidth>100000000</svc-output-bandwidth>
       </service>
   </sites>
   <sites>
       <site-id>Site5</site-id>
       <apply-template>Template-VPNsite-Customer1</apply-template>
       <service>
           <apply-template>Template-VoiceCoS-Cust1</apply-template>
           <svc-input-bandwidth>450000000</svc-input-bandwidth>
           <svc-output-bandwidth>450000000</svc-output-bandwidth>
       </service>
   </sites>

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6.  Service model usage example

   As explained in Section 4, this service model is intended to be
   instantiated at a management layer and is not intended to be used
   directly on network elements.  The management system serves as a
   central point of configuration of the overall service.

   This section provides an example on how a management system can use
   this model to configure an IPVPN service on network elements.

   The example wants to achieve the provisionning of a VPN service for 3
   sites using hub and spoke topology.  One of the site will be dual
   homed and loadsharing is expected.

   +-------------------------------------------------------------+
   |   Hub_Site  ------ PE1               PE2 ------ Spoke_Site1 |
   |      |                   +----------------------------------+
   |      |                   |
   |      |                   +----------------------------------+
   |   Hub_Site  ------ PE3               PE4 ------ Spoke_Site2 |
   +-------------------------------------------------------------+

   The following XML describes the overall simplified service
   configuration of this VPN.

   <vpn-svc>
       <name>VPN1</name>
       <id>12456487</id>
       <customer-name>CUSTOMER1</customer-name>
       <topology>hub-spoke</topology>
   </vpn-svc>

   When receiving the request for provisionning the VPN service, the
   management system will internally (or through discussion with other
   OSS component) allocates VPN route-targets.  In this specific case
   two RTs will be allocated (100:1 for Hub and 100:2 for Spoke).  The
   output below describes the configuration of Spoke1.

   <sites>
       <site-id>Spoke_Site1</site-id>
       <native-vpn>VPN1</native-vpn>
       <site-type>spoke-site</site-type>
       <site-diversity>
           <type>pe-diverse</type>
           <site-group>100</site-group>
       </site-diversity>
       <location>
           <city-code>NY</city-code>

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           <country-code>US</country-code>
       </location>
       <attachment>
           <connection>
               <ipv4>
                   <subnet-prefix>203.0.113.0/30</subnet-prefix>
               </ipv4>
               <routing-protocol>
                   <type>bgp</type>
                   <bgp>
                       <address-family>ipv4-unicast</address-family>
                   </bgp>
               </routing-protocol>
           </connection>
       </attachment>
       <management>
           <type>provider-managed</type>
           <management-transport>ipv4-unicast</management-transport>
           <address>10.46.1.1</address>
       </management>
       <service>
           <svc-input-bandwidth>450000000</svc-input-bandwidth>
           <svc-output-bandwidth>450000000</svc-output-bandwidth>
       </service>
       <customer-specific-information>
           <customer-lan-connection>
               <address>192.0.2.254</address>
               <lan-protocol>ipv4-unicast</lan-protocol>
           </customer-lan-connection>
           <cascaded-lan-prefixes>
               <ipv4-lan-prefixes>
                   <lan>198.51.100.0/30</lan>
                   <nexthop>192.0.2.253</nexthop>
               </ipv4-lan-prefixes>
               <ipv4-lan-prefixes>
                   <lan>198.51.100.4/30</lan>
                   <nexthop>192.0.2.253</nexthop>
               </ipv4-lan-prefixes>
               <ipv4-lan-prefixes>
                   <lan>198.51.100.8/30</lan>
                   <nexthop>192.0.2.253</nexthop>
               </ipv4-lan-prefixes>
           </cascaded-lan-prefixes>
       </customer-specific-information>
   </sites>

   When receiving the request for provisionning Spoke1 site, the
   management system MUST allocate network ressources for this site.  It

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   MUST first decide the target network elements to provision the
   access, and especially the PE router (and may be an aggregation
   switch).  As described in Section 5.2.1, the management system MAY
   use the location information and MUST use the site-diversity
   constraint to find the appropriate PE.  In this case, we consider
   Spoke1 requires PE diversity with Hub and that management system
   allocate PEs based on lowest distance.  Based on the location
   information, the management system finds the available PEs in the
   nearest area of the customer and picks one that fits the site-
   diversity constraint.

   When the PE is chosen, management system needs to allocate interface
   resources on the node, one interface is so picked from the PE
   available pool.  The management system can start provisioning the PE
   node by using any mean (Netconf, CLI, ...).  The management system
   will check if a VRF is already present that fits the needs.  If not,
   it will provision the VRF : Route distinguisher will come from
   internal allocation policy model, route-targets are coming from the
   native-vpn configuration of the site (management system allocated
   some RTs for the VPN).  As the site is a spoke site (site-type), the
   management system knows which RT must be imported and exported.  As
   the site is provider managed, some management route-targets may also
   be added (100:5000).  Standard provider VPN policies MAY also be
   added in the configuration.

   Example of generated PE configuration :

   ip vrf Customer1
    export-map STD-CUSTOMER-EXPORT      <---- Standard SP configuration
    route-distinguisher 100:3123234324
    route-target import 100:1
    route-target import 100:5000        <---- Standard SP configuration
    route-target export 100:2                    for provider managed
   !

   When the VRF has been provisioned, the management system can start
   configuring the access on the PE using the allocated interface
   information.  IP addressing is derived from the subnet-prefix of the
   connection.  One address will be picked from the subnet for the PE,
   another will be used for the CE configuration.  Routing protocols
   will also be configured on the PE, bgp will be used as requested in
   the service model.  Peering addresses will be derived from subnet-
   prefix.  PE AS number is well known and as CE is provider managed, CE
   AS number can be automatically allocated by the management system.
   Some provider standard configuration templates may also be added.

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   Example of generated PE configuration :

   interface Ethernet1/1/0.10
    encapsulation dot1q 10
    ip vrf forwarding Customer1
    ip address 203.0.113.1 255.255.255.252 <---- Comes from
                                                    subnet-prefix
    ip access-group STD-PROTECT-IN     <---- Standard SP config
   !
   router bgp 100
    address-family ipv4 vrf Customer1
     neighbor 203.0.113.2 remote-as 65000   <---- Comes from
                                                 subnet-prefix
                                                 and allocated CE ASN
     neighbor 203.0.113.2 route-map STD in  <---- Standard SP config
     neighbor 203.0.113.2 filter-list 10 in <---- Standard SP config
   !
   ip route vrf Customer1 203.0.113.254 255.255.255.255 203.0.113.2
   ! Static route for provider administration of CE
   !

   As the CE router is not reachable at this stage, the management
   system can produce a complete CE configuration that can be uploaded
   to the node by manual operation before sending the CE to customer
   premise.  The CE configuration will be built as for the PE.  Based on
   the CE type (vendor/model) allocated to the customer and bearer
   information, the management system knows which interface must be
   configured on the CE.  Interface parameters like IP addressing are
   derived from subnet-prefix taking into account how management system
   distributes addresses between PE and CE within the subnet.  Routing
   protocol configuration is done as for the PE, in this example, bgp
   peering address is retrieved from subnet prefix and internal
   allocation policy, remote AS number is well known.  LAN addresses
   will be added to the configuration and exported to BGP.  This will
   permit to produce a plug'n'play configuration for the CE.

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   Example of generated CE configuration :

   interface Loopback10
    description "Administration"
    ip address 203.0.113.254 255.255.255.255
   !
   interface FastEthernet10
    description "WAN"
    ip address 203.0.113.2 255.255.255.252 <---- Comes from
                                                   subnet-prefix
   !
   interface FastEthernet11
    description "LAN"
    ip address 192.0.2.254 255.255.255.252 <---- Comes from
                                             customer-lan-connection
   !
   router bgp 65000
     redistribute static route-map STATIC2BGP <---- Standard SP
                                                       configuration
     neighbor 203.0.113.1 remote-as 100     <---- Comes from
                                                 subnet-prefix
                                                 and allocated CE ASN
   !
   route-map STATIC2BGP permit 10
    match tag 10
   !
   ip route 198.51.100.0 255.255.255.252 192.0.2.253 tag 10
   ip route 198.51.100.4 255.255.255.252 192.0.2.253 tag 10
   ip route 198.51.100.8 255.255.255.252 192.0.2.253 tag 10

7.  Interaction with Other YANG Modules

   As expressed in Section 4, this service module is intended to be
   instantiated in management system and not directly on network
   elements.

   It will be the role of the management system to configure the network
   elements.  The management system MAY be modular, so the component
   instantiating the service model (let's call it service component) and
   the component responsible for network element configuration (let's
   call it configuration component) MAY be different.

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            L3VPN-SVC         |
              service model   |
                              |
                   +----------------------+
                   |   Service component  | service datastore
                   +----------------------+
                              |
                              |
                   +----------------------+
              +----|   Config component   |-------+
             /     +----------------------+        \   Network
            /            /            \             \  Configuration
           /            /              \             \ models
          /            /                \             \
   +++++++         ++++++++             ++++++++       +++++++
   + CEA + ------- + PE A +             + PE B + ----- + CEB + Config
   +++++++         ++++++++             ++++++++       +++++++ datastore

   Site A                                       Site B

   In the previous sections, we provided some example of translation of
   service provisioning request to router configuration lines as
   illustration.  In the NetConf/Yang ecosystem, it will be expected
   NetConf/YANG to be used between configuration component and network
   elements to configure the requested service on these elements.

   In this framework, it is expected from standardization to also work
   on specific configuration YANG modelization of service components on
   network elements.  There will be so a strong relation 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.

   Authors of this document are expecting definition of YANG models for
   network elements on this non exhaustive list of items :

   o  VRF definition including VPN policy expression.

   o  Physical interface.

   o  IP layer (IPv4, IPv6).

   o  QoS : classification, profiles...

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

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   o  Multicast VPN.

   o  Network Address Translation.

   o  ...

   Example of VPN site request at service level using this model :

   <sites>
    <site-id>Site A</site-id>
    <native-vpn>VPN1</native-vpn>
    <site-type>any-to-any-site</site-type>
    <attachment>
     <connection>
      <ipv4>
       <address-allocation-type>static-address</address-allocation-type>
       <subnet-prefix>203.0.113.0/30</subnet-prefix>
      </ipv4>
      <routing-protocol>
       <name>static</name>
       <type>static</type>
      </routing-protocol>
     </connection>
    </attachment>
    <customer-specific-information>
     <cascaded-lan-prefixes>
      <ipv4-lan-prefixes>
       <lan>198.51.100.0/30</lan>
       <nexthop>192.0.2.253</nexthop>
      </ipv4-lan-prefixes>
     </cascaded-lan-prefixes>
    </customer-specific-information>
   </sites>

   In the service example above, it is expected that the service
   component requests to the configuration component of the management
   system the configuration of the service elements.  If we consider
   that service component selected a PE (PE A) as target PE for the
   site, the configuration component will need to push the configuration
   to PE A.  The configuration component will use several YANG data
   models to define the configuration to be applied to PE A.  The XML
   configuration of PE-A may look like this :

   <if:interfaces>
        <if:interface>
         <if:name>eth0</if:name>
         <if:type>ianaift:ethernetCsmacd</if:type>
         <if:description>

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          Link to CEA.
         </if:description>
         <ip:ipv4>
          <ip:address>
           <ip:ip>203.0.113.1</ip:ip>
           <ip:prefix-length>30</ip:prefix-length>
          </ip:address>
          <ip:forwarding>true</ip:forwarding>
         </ip:ipv4>
        </if:interface>
   </if:interfaces>
   <rt:routing>
        <rt:routing-instance>
         <rt:name>VRF_CustA</rt:name>
         <rt:type>l3vpn:vrf</rt:type>
         <rt:description>VRF for CustomerA</rt:description>
         <l3vpn:route-distinguisher>
         100:1546542343
         </l3vpn:route-distinguisher>
         <l3vpn:import-rt>100:1</l3vpn:import-rt>
         <l3vpn:export-rt>100:1</l3vpn:export-rt>
         <rt:interfaces>
          <rt:interface>
           <rt:name>eth0</rt:name>
          </rt:interface>
         </rt:interfaces>
         <rt:routing-protocols>
          <rt:routing-protocol>
           <rt:type>rt:static</rt:type>
           <rt:name>st0</rt:name>
           <rt:static-routes>
            <v4ur:ipv4>
             <v4ur:route>
              <v4ur:destination-prefix>
              198.51.100.0/30
              </v4ur:destination-prefix>
              <v4ur:next-hop>
               <v4ur:next-hop-address>
               203.0.113.2
               </v4ur:next-hop-address>
              </v4ur:next-hop>
             </v4ur:route>
            </v4ur:ipv4>
           </rt:static-routes>
          </rt:routing-protocol>
         </rt:routing-protocols>
        </rt:routing-instance>
   </rt:routing>

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8.  YANG Module

   <CODE BEGINS> file "ietf-l3vpn-svc@2015-07-02.yang"

   module ietf-l3vpn-svc {
       namespace "urn:ietf:params:xml:ns:yang:ietf-l3vpn-svc";

       prefix l3vpn-svc;

       import ietf-routing {
               prefix "rt";
           }

       import ietf-inet-types {
           prefix inet;
       }

       import ietf-yang-types {
           prefix yang;
       }

       organization
        "IETF L3SM Working Group";

       contact
           "WG List:   &lt;mailto:l3sm@ietf.org&gt;

           Editor:

           ";

       description
           "The YANG module defines a generic service configuration
           model for Layer 3 VPN common across all of the vendor
           implementations.";

       revision 2015-07-02 {
           reference "draft-ietf-l3sm-l3vpn-service-yang-00";
       }
       revision 2015-04-24 {
           description "
           * Add encryption parameters
           * Adding holdtime for BFD.
           * Add postal address in location
           ";
           reference "draft-lstd-l3sm-l3vpn-service-yang-00";
       }
       revision 2015-02-05 {

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           description "Initial revision.";
           reference "draft-l3vpn-service-yang-00";
       }

       identity management {
           description
            "Base identity for site management scheme.";
       }
       identity comanaged {
           base management;
           description
            "Base identity for comanaged 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-allocation-type {
           description
            "Base identity for address-allocation-type
            for PE-CE link.";
       }
       identity pe-dhcp {
           base address-allocation-type;
           description
            "PE router provides DHCP service to CE.";
       }
       identity static-address {
           base address-allocation-type;
           description
            "PE-CE addressing is static.";
       }
       identity slaac {
           base address-allocation-type;
           description
            "Use IPv6 SLAAC.";
       }

       identity site-availability {
           description
            "Base identity for site availability.";

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       }
       identity loadsharing {
               base site-availability;
               description
                "Identity for loadsharing site.";
       }
       identity loadsharing-ibgp {
               base loadsharing;
               description
                "Identity for ECMP ibgp based loadsharing site.";
       }
       identity loadsharing-eibgp {
               base loadsharing;
               description
                "Identity for ECMP eibgp based loadsharing site.";
       }
       identity primary-backup {
               base site-availability;
               description
                "Identity for primary-backup site.";
       }
       identity single {
               base site-availability;
               description
                "Identity for single site.";
       }
       identity access-availability-type {
           description
            "base identity for access-availability-type";
       }
       identity primary-access {
           base access-availability-type;
           description
            "Identity for primary access type.";
       }
       identity backup-access {
           base access-availability-type;
           description
            "Identity for backup access type.";
       }
       identity single-access {
           base access-availability-type;
           description
            "Identity for single access type.";
       }
       identity loadsharing-access {
           base access-availability-type;
           description

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            "Identity for loadsharing access type.";
       }

       identity site-type {
           description
            "Base identity for site type.";
       }
       identity any-to-any-site {
           base site-type;
           description
            "Site in a any to any IPVPN.";
       }
       identity spoke-site {
           base site-type;
           description
            "Spoke Site in a Hub & Spoke IPVPN.";
       }
       identity hub-site {
           base site-type;
           description
            "Hub Site in a Hub & Spoke IPVPN.";
       }

       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 multicast-tree-type {
           description

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            "Base identity for multicast tree type.";
       }

       identity ssm-tree-type {
           base multicast-tree-type;
           description
            "Identity for SSM tree type.";
       }
       identity asm-tree-type {
           base multicast-tree-type;
           description
            "Identity for ASM tree type.";
       }
       identity bidir-tree-type {
           base multicast-tree-type;
           description
            "Identity for BiDir tree type.";
       }

       identity multicast-rp-discovery-type {
           description
            "Base identity for rp discovery type.";
       }
       identity auto-rp {
           base multicast-rp-discovery-type;
           description
            "Base identity for auto-rp discovery type.";
       }
       identity static-rp {
           base multicast-rp-discovery-type;
           description
            "Base identity for static type.";
       }
       identity anycast-rp {
           base multicast-rp-discovery-type;
           description
            "Base identity for anycast rp type.";
       }
       identity bsr-rp {
           base multicast-rp-discovery-type;
           description
            "Base identity for BDR discovery type.";
       }

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

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       identity ospf {
           base routing-protocol-type;
           description
            "Identity for OSPF protocol type.";
       }

       identity bgp {
           base routing-protocol-type;
           description
            "Identity for BGP protocol type.";
       }

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

       identity rip {
           base routing-protocol-type;
           description
            "Identity for RIP protocol type.";
       }

       identity rip-ng {
           base routing-protocol-type;
           description
            "Identity for RIPng protocol type.";
       }

       identity vrrp {
           base routing-protocol-type;
           description
            "Identity for VRRP protocol type.
            This is to be used when LAn are directly connected
            to provider Edge routers.";
       }

       identity direct {
           base routing-protocol-type;
           description
            "Identity for direct protocol type.
           .";
       }

       identity l4-protocol-type {
           description
            "Base identity for Layer 4 protocol type.";

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       }

       identity tcp {
           base l4-protocol-type;
           description
            "TCP protocol type.";
       }
       identity udp {
           base l4-protocol-type;
           description
            "UDP protocol type.";
       }
       identity icmp {
           base l4-protocol-type;
           description
            "icmp protocol type.";
       }
       identity icmp6 {
           base l4-protocol-type;
           description
            "icmp v6 protocol type.";
       }
       identity gre {
           base l4-protocol-type;
           description
            "GRE protocol type.";
       }
       identity ipip {
           base l4-protocol-type;
           description
            "IPinIP protocol type.";
       }
       identity hop-by-hop {
           base l4-protocol-type;
           description
            "Hop by Hop IPv6 header type.";
       }
       identity routing {
           base l4-protocol-type;
           description
            "Routing IPv6 header type.";
       }
       identity esp {
           base l4-protocol-type;
           description
            "ESP header type.";
       }
       identity ah {

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           base l4-protocol-type;
           description
            "AH header type.";
       }

       /* Groupings */

       grouping vpn-svc-cfg {
           description
            "Configuration block for l3vpn svc.";

           leaf name {
               type string;
               description
                "Name of the VPN.";
           }
           leaf id {
               type uint32;
               description
               "VPN identifier. Local administration meaning.";
           }
           leaf customer-name {
               type string;
               description
                "Name of the customer.";
           }
           leaf topology {
               type identityref {
                   base vpn-topology;
               }
               description
                "VPN topology.";
           }

           list cloud-access {
               key cloud-identifier;

               leaf cloud-identifier {
                   type string;
                   description
                    "Identification of cloud service. Local
                    admin meaning.";
               }
               list authorized-sites {
                   key site-id;

                   leaf site-id {

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                       type leafref {
                           path "../../../../sites/site-id";
                       }
                       description
                        "Site ID.";
                   }
                   description
                    "List of authorized sites.";
               }
               list denied-sites {
                   key site-id;

                   leaf site-id {
                       type leafref {
                           path "../../../../sites/site-id";
                       }
                       description
                        "Site ID.";
                   }
                   description
                    "List of denied sites.";
               }
               leaf nat-enabled {
                   type boolean;
                   description
                    "Control if NAT is required or not.";
               }
               leaf customer-nat-address {
                   type inet:ipv4-address;
                   description
                    "NAT address to be used in case of public
                    or shared cloud.
                    This is to be used in case customer is providing
                    the public address.";
               }
               description
                "Cloud access configuration.";
           }

           container multicast {
               leaf-list tree-flavor {
                   type identityref {
                       base multicast-tree-type;
                   }
                   description
                    "Type of tree to be used.";
               }
               container rp {

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                   leaf ipv4-address {
                       type inet:ipv4-address;
                       description
                        "Management address";
                   }
                   leaf ipv6-address {
                       type inet:ipv6-address;
                       description
                        "Management address";
                   }
                   description
                    "Defines the address of the RendezvousPoint.";
               }
               leaf rp-discovery {
                   type identityref {
                       base multicast-rp-discovery-type;
                   }
                   description
                    "Type of RP discovery used.";
               }
               leaf-list anycast-rp-location {
                   type string;
                   description
                    "Encodes the location of the RPs in anycast RP
                    deployment.";
               }
               description
                   "Multicast global parameters for the VPN service.";
           }
       }

       /* Main blocks */

       container l3vpn-svc {
           list vpn-svc {
               key name;

               uses vpn-svc-cfg;

               description "
                   List of VPN services.
                   ";
           }

           list sites {
               key site-id;

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               leaf template {
                   type boolean;
                   default false;
                   description
                    "Defines if the site is a real site,
                    or a configuration template.";
               }

               leaf site-id {
                   type string;
                   description
                       "Identifier of the site.";
               }

               leaf native-vpn {
                   type leafref {
                       path "../../vpn-svc/name";
                   }
                   description
                       "Reference to associated VPN.";
               }

               leaf site-type {
                   type identityref {
                       base site-type;
                   }
                   description
                       "Type of site.";
               }

               leaf apply-template {
                   type leafref {
                       path "../../sites/site-id";
                   }
                   description
                    "It we would be good to ensure that
                    site-id is template type";
               }
               leaf requested-site-start {
                      type yang:date-and-time;
                      description
                       "Optional leaf indicating requested date
                       and time
                       when the service at a particular site is
                       expected
                       to start";
                  }

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                  leaf requested-site-stop {
                      type yang:date-and-time;
                      description
                       "Optional leaf indicating requested date
                       and time
                       when the service at a particular site is
                       expected
                       to stop";
                  }

                  leaf actual-site-start {
                      type yang:date-and-time;
                      description
                       "Optional leaf indicating actual date
                       and time
                       when the service at a particular site
                       actually
                       started";
                  }
                  leaf actual-site-stop {
                      type yang:date-and-time;
                      description
                       "Optional leaf indicating actual date
                       and time
                       when the service at a particular site
                       actually
                       stopped";
                  }
               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 city {
                       type string;
                       description
                        "City of the site.";
                   }
                   leaf country-code {
                       type string;

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                       description
                        "Country of the site.";
                   }
                   description
                       "Location of the site.";
               }

               container site-diversity {
                   leaf type {
                       type enumeration {
                           enum "pop-diverse" {
                               description
                                "The access must use another PoP
                                compared
                                to other accesses in the same group.";
                           }
                           enum "pe-diverse" {
                               description
                                "The access must use another PE
                                compared
                                to other accesses in the same group.";
                           }
                       }
                       description
                        "Diversity constraint type.";
                   }

                   leaf-list site-group {
                       type uint32;
                       description
                        "IDs of group.";
                   }
                   description
                        "Diversity constraint type.";
               }

               container security {
                   leaf apply-template {
                       type leafref {
                           path "../../../sites/site-id";
                       }
                       description
                        "It we would be good to ensure that site-id is
                        template type";
                   }
                   container authentication {
                       description
                        "Authentication parameters";

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                   }
                   container encryption {
                       leaf enabled {
                           type boolean;
                           description
                            "If true, access encryption is required.";
                       }
                       leaf layer {
                           type enumeration {
                               enum layer2 {
                                   description
                                    "Encryption will occur at layer2.";
                               }
                               enum layer3 {
                                   description
                                    "IPSec is requested.";
                               }
                           }
                           description
                            "Layer on which encryption is applied.";
                       }
                       container encryption-profile {
                           choice profile {
                               case provider-profile {
                                   leaf profile-name {
                                       type string;
                                       description
                                        "Name of the SP profile
                                        to be applied.";
                                   }
                               }
                               case customer-profile {
                                   leaf algorithm {
                                       type string;
                                       description
                                        "Encryption algorithm to
                                        be used.";
                                   }
                                   choice key-type {
                                       case psk {
                                           leaf preshared-key {
                                               type string;
                                               description
                                                "Key coming from
                                                customer.";
                                           }
                                       }
                                       case pki {

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                                       }
                                       description
                                        "Type of keys to be used.";
                                   }
                               }
                               description
                                "Choice of profile.";
                           }
                           description
                            "Profile of encryption to be applied.";
                       }
                       description
                        "Encryption parameters.";
                   }
                   container access-control-list {
                       description
                        "Access control list.";
                   }
                   description
                    "Site specific security parameters.";
               }

               container availability {
                   container availability-type {
                       leaf service-type {
                           type identityref {
                               base site-availability;
                           }
                           description
                            "Type of availability,
                            ex : single, backup, loadsharing";
                       }
                       leaf access-type {
                           type identityref {
                               base access-availability-type;
                           }
                           description
                            "Access type within the service.";
                       }
                       description
                           "Availability solution parameters";
                   }
                   leaf loadsharing-type {
                       type identityref {
                           base loadsharing;
                       }
                       description
                        "Loadsharing flavor.";

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                   }
                   description
                    "Site availability parameters.";
               }
               container attachment {
                   leaf apply-template {
                       type leafref {
                           path "../../../sites/site-id";
                       }
                       description
                        "It we would be good to ensure
                        that site-id is
                        template type";
                   }
                   container bearer {
                       leaf type {
                           type string;
                           description
                            "Type of bearer Ethernet, DSL, Wireless ...
                            Operator specific.";
                       }
                       leaf bearer-reference {
                           type string;
                           description
                            "This is an internal reference for the
                            service provider.";
                       }
                       description
                        "Bearer specific parameters.
                        To be augmented.";
                   }
                   container connection {
                       container ipv4 {
                           leaf address-allocation-type {
                               type identityref {
                                   base address-allocation-type;
                               }
                               description
                                "Defines how addresses are allocated.
                                Need to be detailed further.";
                           }
                           leaf subnet-prefix {
                               type inet:ipv4-prefix;
                               description
                                "Interco subnet.";
                           }
                           description
                            "IPv4 specific parameters";

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                       }
                       container ipv6 {
                           leaf address-allocation-type {
                               type string;
                               description
                                "Defines how addresses are allocated.
                                Need to be detailled further.";
                           }
                           leaf subnet-prefix {
                               type inet:ipv6-prefix;
                               description
                                "Interco subnet.";
                           }
                           description
                            "IPv6 specific parameters";

                       }
                       list routing-protocols {
                           key type;

                           leaf type {
                               type identityref {
                                   base routing-protocol-type;
                               }
                               description
                                "Type of routing protocol.";
                           }

                           container ospf {
                               when "type = 'ospf'" {
                                   description
                                    "Only applies
                                    when protocol is OSPF.";
                               }
                               leaf-list address-family {
                                   type identityref {
                                       base rt:address-family;
                                   }
                                   description
                                    "Address family to be activated.";
                               }
                               leaf area-address {
                                   type yang:dotted-quad;
                                   description
                                    "Area address.";
                               }
                               leaf metric {

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                                   type uint16;
                                   description
                                    "Metric of PE-CE link.";
                               }
                               list sham-link {
                                   key target-site;

                                   leaf target-site {
                                       type leafref {
                                           path "../../../../../../"
                                           +"../sites/site-id";
                                       }
                                       description
                                        "Target site for the sham link
                                         connection.";
                                   }
                                   leaf metric {
                                       type uint16;
                                       description
                                        "Metric of the sham link.";
                                   }
                                   description
                                    "Creates a shamlink with another
                                    site";
                               }
                               description
                                "OSPF specific configuration.";
                           }

                           container bgp {
                               when "type = 'bgp'" {
                                   description
                                    "Only applies when
                                    protocol is BGP.";
                               }
                               leaf-list address-family {
                                   type identityref {
                                       base rt:address-family;
                                   }
                                   description
                                    "Address family to be activated.";
                               }
                               description
                                "BGP specific configuration.";
                           }
                           container static {
                               when "type = 'static'" {
                                   description

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                                    "Only applies when protocol
                                    is static.";
                               }
                               leaf-list address-family {
                                   type identityref {
                                       base rt:address-family;
                                   }
                                   description
                                    "Address family to be activated.";
                               }
                               description
                                "Static routing
                                specific configuration.";
                           }
                           container rip {
                               when "type = 'rip'" {
                                   description
                                    "Only applies when
                                    protocol is RIP.";
                               }
                               leaf-list address-family {
                                   type identityref {
                                       base rt:address-family;
                                   }
                                   description
                                    "Address family to be
                                    activated.";
                               }

                               description
                                "RIP routing specific
                                configuration.";
                           }

                           container vrrp {
                               when "type = 'vrrp'" {
                                   description
                                    "Only applies when
                                    protocol is VRRP.";
                               }
                               leaf-list address-family {
                                   type identityref {
                                       base rt:address-family;
                                   }
                                   description
                                    "Address family to be activated.";
                               }

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                               description
                                "VRRP routing specific configuration.";
                           }

                           container 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 holdtime
                                            expressed
                                            in msec.";
                                       }
                                   }
                                   description
                                    "Choice for holdtime flavor.";
                               }
                               description
                                "Container for BFD.";
                           }
                           description
                            "List of routing protocols used
                            on the site.
                            Need to be augmented.";
                       }
                       description
                        "Defines connection parameters.";
                   }

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                   description
                    "Parameters of the attachement.";
               }

               container service {
                   leaf apply-template {
                       type leafref {
                           path "../../../sites/site-id";
                       }
                       description
                        "It we would be good to ensure that site-id is
                        template type";
                   }
                   container qos {
                       container qos-classification-policy {
                           list rules {
                               key id;

                               leaf id {
                                   type uint16;
                                   description
                                    "ID of the rule.";
                               }
                               container match {
                                   leaf ipv4-src-prefix {
                                       type inet:ipv4-prefix;
                                       description
                                        "Match on IPv4 src address.";
                                   }
                                   leaf ipv6-src-prefix {
                                       type inet:ipv6-prefix;
                                       description
                                        "Match on IPv6 src address.";
                                   }
                                   leaf ipv4-dst-prefix {
                                       type inet:ipv4-prefix;
                                       description
                                        "Match on IPv4 dst address.";
                                   }
                                   leaf ipv6-dst-prefix {
                                       type inet:ipv6-prefix;
                                       description
                                        "Match on IPv6 dst address.";
                                   }
                                   leaf l4-src-port {
                                       type uint16;
                                       description
                                        "Match on layer 4 src port.";

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                                   }
                                   leaf l4-dst-port {
                                       type uint16;
                                       description
                                        "Match on layer 4 dst port.";
                                   }
                                   leaf l4-protocol {
                                       type union {
                                           type uint8;
                                           type identityref {
                                               base l4-protocol-type;
                                           }
                                       }
                                       description
                                        "Match on IPv4 protocol
                                        field or
                                        IPv6 nextheader field.";
                                   }
                                   description
                                    "Describe flow matching
                                    criterions.";
                               }

                               leaf target-class-id {
                                   type string;
                                   description
                                    "Identification of the
                                    class of service.
                                    This identifier is internal to
                                    the administration.";
                               }

                               description
                                "List of marking rules.";
                           }
                           description
                            "Need to express marking rules ...";
                       }
                       leaf std-qos-profile {
                           type string;
                           description
                            "QoS profile to be used";
                       }
                       container custom-qos-profile {
                           list class {
                               key class-id;

                               leaf class-id {

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                                   type string;
                                   description
                                    "Identification of the
                                    class of service.
                                    This identifier is internal to
                                    the administration.";
                               }
                               leaf rate-limit {
                                   type uint8;
                                   units percent;
                                   description
                                    "To be used if class must
                                    be rate
                                    limited. Expressed as
                                    percentage of the svc-bw.";
                               }
                               leaf priority-level {
                                   type uint8;
                                   description
                                    "Defines the level of the
                                    class in
                                    term of priority queueing.
                                     The higher the level is the
                                     higher
                                     is the priority.";
                               }
                               leaf guaranteed-bw-percent {
                                   type uint8;
                                   units percent;
                                   description
                                    "To be used to define the
                                    guaranteed
                                    BW in percent of the svc-bw
                                    available at the priority-level.";
                               }
                               description
                                "List of class of services.";
                           }
                           description
                            "Custom qos profile.";
                       }
                       description
                        "QoS configuration.";
                   }

                   leaf svc-input-bandwidth {
                          type uint32;
                          units bps;

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                          description
                           "From the PE perspective, the service input
                           bandwidth of the connection.";
                   }

                   leaf svc-output-bandwidth {
                      type uint32;
                      units bps;
                      description
                       "From the PE perspective, the service output
                       bandwidth of the connection.";
                   }
                   leaf svc-mtu {
                       type uint16;
                       units bytes;
                       description
                        "MTU at service level.
                        If the service is IP,
                        it refers to the IP MTU.";
                   }

                   container traffic-protection {
                       leaf link-local-protection {
                           type boolean;
                           description
                            "Enables protection of PE-CE link.";
                       }
                       leaf node-local-protection {
                           type boolean;
                           description
                            "Enables protection against local
                            PE node failure.";
                       }
                       leaf node-global-protection {
                           type boolean;
                           description
                           "Enables protection against remote
                           PE node failure.
                           This is also called PIC Edge.
                           ";
                       }
                       description
                        "Fast reroute service parameters
                        for the site.";
                   }
                   container mpls {
                       leaf signalling-type {
                           type enumeration {

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                               enum "ldp" {
                                   description
                                       "Use LDP as signalling
                                       protocol between PE and CE.";
                               }
                               enum "bgp" {
                                   description
                                       "Use BGP 3107 as signalling
                                       protocol between PE and CE.
                                       In this case, bgp must be also
                                       configured
                                       as routing-protocol.
                                       ";
                               }
                           }
                           description
                            "MPLS signalling type.";
                       }
                       description
                        "This container is used when customer provides
                        MPLS based services.
                        This is used in case of Carrier
                        Supporting Carrier.";
                   }
                   container multicast {
                       leaf site-type {
                           type enumeration {
                               enum receiver-only {
                                   description
                                    "The site has only receivers.";
                               }
                               enum source-only {
                                   description
                                    "The site has only sources.";
                               }
                               enum source-receiver {
                                   description
                                    "The site has both
                                    sources & receivers.";
                               }
                           }
                           description
                            "Type of multicast site.";
                       }

                       description
                        "Multicast parameters for the site.";
                   }

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                   description
                    "Service parameters on the attachement.";
               }

               container management {
                   leaf type {
                       type identityref {
                           base management;
                       }
                       description
                       "Management type of the connection.";
                   }
                   leaf management-transport {
                       type identityref {
                           base rt:address-family;
                       }
                       description
                        "Transport protocol used for management.";
                   }
                   leaf address {
                       type union {
                           type inet:ipv4-address;
                           type inet:ipv6-address;
                       }
                       description
                        "Management address";
                   }

                   description
                    "Management configuration";
               }

               container vpn-policy {
                   container import-policy {
                       leaf-list vpn {
                           type leafref {
                               path "../../../../vpn-svc/name";
                           }
                           description
                            "Reference to an IPVPN.";
                       }
                   description
                        "Import policy.";
                   }
                   container export-policy {
                       list entries {
                           key id;

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                           leaf id {
                               type uint32;
                               description
                                "Unique identifier for
                                 the export policy entry.";
                           }
                           container lan-prefixes {
                               list ipv4-lan-prefixes {
                                   key lan;

                                   leaf lan {
                                       type inet:ipv4-prefix;
                                       description
                                        "Lan prefixes.";
                                   }
                                   description "
                                       List of LAN prefixes
                                       for the site.
                                       ";
                               }
                               list ipv6-lan-prefixes {
                                   key lan;

                                   leaf lan {
                                       type inet:ipv6-prefix;
                                       description
                                        "Lan prefixes.";
                                   }
                                   description "
                                       List of LAN prefixes
                                       for the site.
                                       ";
                               }
                               description
                                "LAN prefixes from the customer.";
                           }
                           leaf-list lan-tag {
                               type string;
                               description
                                "List of lan-tags to be matched.";
                           }
                           leaf-list vpn {
                               type leafref {
                                   path "../../../../../vpn-svc/name";
                               }
                               description
                                "Reference to an IPVPN.";
                           }

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                           description
                            "List of entries for export policy.";
                       }
                       description
                        "Export policy.";

                   }
                   description
                    "Define attachment to VPNs that are not the
                     attachment VPN.
                     Use to permit multiple VPN sites.";
               }

               container maximum-routes {
                   list address-family {
                       key af;

                       leaf af {
                           type identityref {
                               base rt:address-family;
                           }
                           description
                            "Address-family.";
                       }
                       leaf maximum-routes {
                           type uint32;
                           description
                            "Maximum prefixes the VRF can
                            accept for this
                            address-family.";
                       }
                       description
                        "List of address families.";
                   }

                   description
                    "Define maximum-routes for the VRF.";
               }

               container customer-specific-information {
                   leaf name {
                       type string;
                       description
                        "Name of the customer router.";
                   }
                   leaf autonomous-system {
                       type uint32;
                       description

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                        "AS number.";
                   }
                   leaf interface {
                       type string;
                       description
                        "Interface reference of the access.";
                   }
                   list customer-lan-connection {
                       key "address";
                       leaf address {
                           type union {
                               type inet:ipv4-address;
                               type inet:ipv6-address;
                           }
                           description
                            "Address given by the customer on its LAN
                           for the SP router.";
                       }
                       leaf lan-protocol {
                           type identityref {
                               base rt:address-family;
                           }
                           description
                            "Transport protocol used on LAN.";
                       }
                       description
                        "List of customer LAN to be connected
                        directly on the CE.";
                   }
                   container cascaded-lan-prefixes {
                       list ipv4-lan-prefixes {
                           key lan;

                           leaf lan {
                               type inet:ipv4-prefix;
                               description
                                "Lan prefixes.";
                           }
                           leaf lan-tag {
                               type string;
                               description
                                "Internal tag to be used in vpn
                                policies.";
                           }
                           leaf next-hop {
                               type inet:ipv4-address;
                               description
                                "Nexthop address to use at customer

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                                side.";
                           }
                           description "
                               List of LAN prefixes for
                               the site.
                               ";
                       }
                       list ipv6-lan-prefixes {
                           key lan;

                           leaf lan {
                               type inet:ipv6-prefix;
                               description
                                "Lan prefixes.";
                           }
                           leaf lan-tag {
                               type string;
                               description
                                "Internal tag to be used
                                in vpn policies.";
                           }
                           leaf next-hop {
                               type inet:ipv6-address;
                               description
                                "Nexthop address to use at
                                customer side.";
                           }
                           description "
                               List of LAN prefixes for the site.
                               ";
                       }
                       description
                           "LAN prefixes from the customer.";
                   }

                   description
                    "Customer premise configuration.";
               }

               description "List of sites.";
           }

           description
            "Main container for L3VPN service configuration.";
       }

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   }
   <CODE ENDS>

9.  To do list / Open questions / Open issues

   Open questions :

   o  Do we need to handle service chaining for the L3VPN service ?

   Open issues :

   o

   TODO :

   o  Security items

   o  Bearer details

   o  ...

10.  Security Considerations

   TBD.

11.  Contributors

12.  Acknowledgements

   Thanks to Qin Wu, Maxim Klyus, Luis Miguel Contreras, Gregory Mirsky,
   Zitao Wang, Jing Zhao, and Andrew Leu for the contributions to the
   document.

13.  IANA Considerations

   TBD.

14.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC4110]  Callon, R. and M. Suzuki, "A Framework for Layer 3
              Provider-Provisioned Virtual Private Networks (PPVPNs)",
              RFC 4110, July 2005.

   [RFC4364]  Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private
              Networks (VPNs)", RFC 4364, February 2006.

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   [RFC4577]  Rosen, E., Psenak, P., and P. Pillay-Esnault, "OSPF as the
              Provider/Customer Edge Protocol for BGP/MPLS IP Virtual
              Private Networks (VPNs)", RFC 4577, June 2006.

   [RFC4862]  Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless
              Address Autoconfiguration", RFC 4862, September 2007.

   [RFC6020]  Bjorklund, M., "YANG - A Data Modeling Language for the
              Network Configuration Protocol (NETCONF)", RFC 6020,
              October 2010.

   [RFC6241]  Enns, R., Bjorklund, M., Schoenwaelder, J., and A.
              Bierman, "Network Configuration Protocol (NETCONF)", RFC
              6241, June 2011.

   [RFC6513]  Rosen, E. and R. Aggarwal, "Multicast in MPLS/BGP IP
              VPNs", RFC 6513, February 2012.

Appendix A.  Example: NETCONF <get> Reply

   This section gives an example of a reply to the NETCONF <get> request
   for a device that implements the data model defined in this document.
   The example is written in XML.

Authors' Addresses

   Stephane Litkowski
   Orange Business Service

   Email: stephane.litkowski@orange.com

   Rob Shakir
   BT

   Email: rob.shakir@bt.com

   Luis Tomotaki
   Verizon

   Email: luis.tomotaki@verizon.com

   Kevin D'Souza
   ATT

   Email: kd6913@att.com

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