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YANG Data Model for IPv4-in-IPv6 Softwire
draft-sun-softwire-yang-00

The information below is for an old version of the document.
Document Type
This is an older version of an Internet-Draft whose latest revision state is "Replaced".
Authors Qi Sun , Hao Wang , Yong Cui , Ian Farrer
Last updated 2014-10-20
Replaced by draft-ietf-softwire-yang, draft-ietf-softwire-yang, draft-ietf-softwire-yang, draft-ietf-softwire-yang, RFC 8676
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draft-sun-softwire-yang-00
Softwire Working Group                                            Q. Sun
Internet-Draft                                                   H. Wang
Intended status: Standards Track                                  Y. Cui
Expires: April 23, 2015                              Tsinghua University
                                                               I. Farrer
                                                     Deutsche Telekom AG
                                                        October 20, 2014

               YANG Data Model for IPv4-in-IPv6 Softwire
                       draft-sun-softwire-yang-00

Abstract

   This document defines a YANG data model for the configuration and
   management of IPv4-in-IPv6 Softwire Concentrators containing a
   Network Configuration Protocol (NETCONF) server.  The models cover
   A+P [RFC6346], encapsulation based softwires.

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

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

   This Internet-Draft will expire on April 23, 2015.

Copyright Notice

   Copyright (c) 2014 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

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

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   3
     1.2.  Tree Diagram  . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Objectives  . . . . . . . . . . . . . . . . . . . . . . . . .   3
     2.1.  Common  . . . . . . . . . . . . . . . . . . . . . . . . .   3
     2.2.  Lightweight 4over6  . . . . . . . . . . . . . . . . . . .   4
     2.3.  MAP-E . . . . . . . . . . . . . . . . . . . . . . . . . .   4
   3.  Softwire YANG Data Model  . . . . . . . . . . . . . . . . . .   4
     3.1.  Common Data Tree  . . . . . . . . . . . . . . . . . . . .   4
     3.2.  Lightweight 4over6 Data Tree  . . . . . . . . . . . . . .   4
     3.3.  MAP-E Data Tree . . . . . . . . . . . . . . . . . . . . .   5
   4.  Softwire YANG Module  . . . . . . . . . . . . . . . . . . . .   7
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .  14
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  14
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  15
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  15
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .  15
     8.2.  Informative References  . . . . . . . . . . . . . . . . .  15
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  16

1.  Introduction

   The IETF Softwire Working Group has developed several IPv4-in-IPv6
   Softwire mechanisms for different scenarios.  This document defines a
   YANG data model that can be used to configure and manage the IPv4-in-
   IPv6 Softwire Concentrator (Border Router).

   Due to the inherent similarities of the data plane forwarding, the
   YANG models that are described in this document are for Lightweight
   4o6 [I-D.ietf-softwire-lw4over6] and MAP-E [I-D.ietf-softwire-map].

   DISCUSSION POINT: Should the draft be extended to include MAP-T, 4rd
   and DS-Lite?

   The models define several containers.  Container "softwire-config"
   holds a collection of YANG definitions common to all softwire
   configuration.  Container "softwire-state" holds YANG definitions for

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   the operational state of the Softwire Concentrator.

   The softwire mechanism specifics each have their own indivial YANG
   modules:

   o  Lightweight 4over6

   o  MAP-E

   This approach has been taken so that the model can be easily extended
   in the future to support addional softwire mechanism, should this be
   necessary.

1.1.  Terminology

   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].

   The reader should be familiar with the terms define by the IETF
   Softwire working group, and relevant documents and the YANG data
   modelling language [RFC6020].

1.2.  Tree Diagram

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

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

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

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

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

2.  Objectives

2.1.  Common

   This YANG model intends to abstract the shared features of different
   Concentrators such as softwire type, maximum number of softwires,
   etc.

   Since different concentrators have specialised functions, the
   following sections describe the model objectives for those solutions.

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   The following model is the root of the softwire YANG model.  All
   functions are listed, but the YANG model uses the "feature" statement
   to distinguish different softwire mechanisms.

2.2.  Lightweight 4over6

   The IPv4-IPv6 address binding information needs to be configured to
   Lightweight AFTR so that the state synchronisation can be achieved
   between the provisioning system and the lwAFTR.

2.3.  MAP-E

   The provisioning system or administrator needs to configure the
   corret MAP rules on the MAP BR.

3.  Softwire YANG Data Model

3.1.  Common Data Tree

   Figure 1 below describes the softwire data model which is common
   between all of the different softwire mechanisms:

      +--rw softwire-config
      |  +--rw enabled?                             boolean
      |  +--rw name?                                string
      |  +--rw description?                         string
      |  +--rw softwire-num-threshold               uint32
      |  +--rw tunnel-mtu                           uint32
      |  +--rw lw4over6
      |  +--rw map-e
      +--ro softwire-state
         +--ro enabled?                             boolean
         +--ro name?                                string
         +--rw description?                         string
         +--ro tunnel-mtu                           uint32
         +--ro lw4over6
         +--ro map-e

              Figure 1: Softwire Common Data Model Structure

   The mechanism specific models for lw4o6 and MAP-E are described in
   detail in the following sections.

3.2.  Lightweight 4over6 Data Tree

   Figure 2 below defines the softwire data model for Lightweight
   4over6:

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   +--rw softwire-config
   |  +--...
   |  +--rw lw4over6
   |     +--rw lwaftrs
   |        +--rw lwaftr* [id]
   |           +--rw id                                uint32
   |           +--rw lwaftr-ipv6-addr                  inet:ipv6-address
   |           +--rw binding-table
   |              +--rw binding-entry* [id]
   |                 +--rw id                          uint32
   |                 +--rw binding-ipv4-addr           inet:ipv4-address
   |                 +--rw port-set
   |                 |  +--rw offset                   uint8
   |                 |  +--rw psid-len                 uint8
   |                 |  +--rw psid                     inet:port-number
   |                 +--rw binding-ipv6-addr           inet:ipv6-address
   |                 +--rw active                      boolean
   +--ro softwire-state
      +--...
      +--ro lw4over6
         +--ro lwaftrs
            +--ro lwaftr* [id]
               +--ro id                                uint32
               +--ro lwaftr-ipv6-addr                  inet:ipv6-address
               +--ro binding-table
                  +--ro binding-entry* [id]
                     +--ro id                          uint32
                     +--ro binding-ipv4-addr           inet:ipv4-address
                     +--ro port-set
                     |  +--ro offset                   uint8
                     |  +--ro psid-len                 uint8
                     |  +--ro psid                     inet:port-number
                     +--ro binding-ipv6-addr           inet:ipv6-address
                     +--ro active                      boolean

        Figure 2: Softwire Lightweight 4over6 Data Model Structure

   Node that the "active" item is used to determine whether the binding
   entry should be deleted.

3.3.  MAP-E Data Tree

   Figure 3 below defines the softwire data model for MAP-E:

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   +--rw softwire-config
   |  +--...
   |  +--rw map-e
   |     +--rw map-brs
   |        +--rw map-br* [id]
   |           +--rw id                                unit32
   |           +--rw br-ipv6-addr                      inet:ipv6-address
   |           +--rw map-rule-table
   |              +--rw map-rule-entry* [id]
   |                 +--rw id                          uint8
   |                 +--rw IPv6-prefix                 inet:ipv6-address
   |                 +--rw IPv6-prefix-len             uint8
   |                 +--rw IPv4-prefix                 inet:ipv4-address
   |                 +--rw IPv4-prefix-len             uint8
   |                 +--rw port-set
   |                 |  +--rw offset                   uint8
   |                 |  +--rw psid-len                 uint8
   |                 |  +--rw psid                     inet:port-number
   |                 +--rw ea-len                      uint8
   |                 +--rw active                      boolean
   +--ro softwire-state
      +--...
      +--ro map-e
         +--ro map-brs
            +--ro map-br* [id]
               +--ro id                                uint32
               +--ro br-ipv6-addr                      inet:ipv6-address
               +--ro map-rule-table
                  +--ro map-rule-entry* [id]
                  |  +--ro id                          uint8
                  |  +--ro IPv6-prefix                 inet:ipv6-address
                  |  +--ro IPv6-prefix-len             uint8
                  |  +--ro IPv4-prefix                 inet:ipv4-address
                  |  +--ro IPv4-prefix-len             uint8
                  |  +--ro port-set
                  |  |  +--ro offset                   uint8
                  |  |  +--ro psid-len                 uint8
                  |  |  +--ro psid                     inet:port-number
                  |  +--ro ea-len                      uint8
                  |  +--ro active                      boolean
                  +--ro active-map-rule-num            uint8

               Figure 3: Softwire MAP-E Data Model Structure

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4.  Softwire YANG Module

   This module imports typedefs from [RFC6991].

  <CODE BEGINS> file "ietf-softwire@2014-10-20.yang"

  module softwire {
    namespace "urn:ietf:params:xml:ns:yang:softwire";
    prefix "softwire";

    import ietf-inet-types { prefix inet; }

    organization "softwire";

    contact
      "
      Qi Sun sunqi@csnet1.cs.tsinghua.edu.cn
      Hao Wang wangh13@mails.tsinghua.edu.cn
      Yong Cui yong@csnet1.cs.tsinghua.edu.cn
      Ian Farrer ian.farrer@telekom.de
      ";

    description
      "This document defines a YANG data model that can be used to
      configure and manage softwire concentrators.
      Copyright (c) 2014 IETF Trust and the persons identified
      as authors of the code. All rights reserved.
      This version of this YANG module is part of RFC XXX; see the RFC
      itself for full legal notices.";

    revision 2014-10-20 {
      description
        "Initial revision.";
    }

  /*
   * Typedef
   */

  /*
   * Features
   */

    feature lw4over6 {
      description
        "Lightweight 4over6 moves the Network Address and Port

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        Translation (NAPT) function from the centralized DS-Lite tunnel
        concentrator to the tunnel client located in the Customer
        Premises Equipment (CPE).  This removes the requirement for a
        Carrier Grade NAT function in the tunnel concentrator and
        reduces the amount of centralized state that must be held to a
        per-subscriber level.  In order to delegate the NAPT function
        and make IPv4 Address sharing possible, port-restricted IPv4
        addresses are allocated to the CPEs.";
      reference
        "I-D.ietf-softwire-lw4over6";
    }

    feature map-e {
      description
        "MAP-E is a mechanism for transporting IPv4 packets across an
        IPv6 network using IP encapsulation, and a generic mechanism
        for mapping between IPv6 addresses and IPv4 addresses and
        transport layer ports.";
      reference
        "I-D.ietf-softwire-map";
    }

  /*
   * Grouping
   */

    grouping port-set {
      description
        "A range of transport layer ports.";
      leaf offset {
        type uint8;
        default "0";
        description
          "The number of offset bits.";
      }
      leaf psid-len {
        type uint8;
        description
          "The length of Port Set Identifier (PSID).";
      }
      leaf psid {
        type inet:port-number;
        description
          "Algorithmically identifies a set of ports.";
      }
    }

    grouping binding-table {

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      description
        "The lwAFTR maintains an address binding table containing the
        binding between the lwB4's IPv6 address, the allocated IPv4
        address and restricted port-set.";
      list binding-entry {
        key "id";
        leaf id {
          type uint32;
        }
        leaf binding-ipv4-addr {
          type inet:ipv4-address;
          description
            "The IPv4 address assigned to a lwB4, which is used as the
            IPv4 External Address for lwB4 local NAPT44. One of three
            elemnts constructing a binding entry.";
        }
        container port-set {
          uses port-set;
        }
        leaf binding-ipv6-addr {
          type inet:ipv6-address;
          description
            "The IPv6 address of the lwB4, which is used to bind the
            IPv4 address and port-set.";
        }
        leaf active {
          type boolean;
          description
            "Used to delete the inactive binding-entries.";
        }
      }
    }

    grouping map-rule-table {
      description
        "The (conceptual) table containing rule Information for
        a specific mapping rule. It can also be used for row creation.";
      list map-rule-entry {
        key "id";
        leaf id {
          type uint8;
        }
        leaf IPv6-prefix {
          type inet:ipv6-address;
          description
            "The IPv6 prefix defined in the mapping rule which will be
            assigned to CE.";
        }

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        leaf IPv6-prefix-len {
          type uint8;
          description
            "The length of the IPv6 prefix defined in the mapping rule.
            As a parameter for the mapping rule, it will be also assigned
            to CE.";
        }
        leaf IPv4-prefix {
          type inet:ipv4-address;
          description
            "The IPv4 prefix defined in the mapping rule which will be
            assigned to CE.";
        }
        leaf IPv4-prefix-len {
          type uint8;
          description
            "The length of the IPv4 prefix defined in the mapping
            rule. As a parameter for the mapping rule, it will be also
            assigned to CE.";
        }
        container port-set {
          uses port-set;
        }
        leaf ea-len {
          type uint8;
          description
            "The length of the Embedded-Address (EA) defined in
            mapping rule which will be assigned to CE.";
        }
        leaf active {
          type boolean;
          description
              "Used to delete inactive map-rule-entries.";
        }
      }
    }

  /*
   * Configuration Data Nodes
   */

    container softwire-config {
      description
        "The configuration data for concentrators in softwire. ";
      leaf enabled {
        type boolean;
        default "true";
        description

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          "Enable/disable the Softwire concentrator function.";
      }
      leaf name {
        type string;
        description
          "The name of the softwire concentrator.";
      }
      leaf description {
        type string;
        description
          "A textual description of the softwire concentrator.";
      }
      leaf softwire-num-threshold {
        type uint32;
        description
          "The maximum number of tunnels that can be created on
          the concentrator.";
      }
      leaf tunnel-mtu {
        type uint32;
        description
          "The MTU of tunnel payload on the softwire concentrator.";
      }
      container lw4over6 {
        if-feature lw4over6;
        description
          "Indicate this device supports the Lightweight 4over6 function.
          Devices advertise the lw4over6 feature through the capability
          exchange mechanism when a NETCONF session is established.";
        container lwaftrs {
          description
            "An AFTR element (Address Family Transition Router element
            [RFC6333]), which supports Lightweight 4over6 extension.
            An lwAFTR is an IPv4-in-IPv6 tunnel endpoint which maintains
            per-subscriber address binding only and does not perform a
            NAPT44 function.";
          list lwaftr {
            key "id";
            leaf id {
              type uint32;
            }
            leaf lwaftr-ipv6-addr {
              type inet:ipv6-address;
              description
                "The IPv6 address of the lwAFTR.";
            }
            container binding-table {
              uses binding-table;

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            }
          }
        }
      }
      container map-e {
        if-feature map-e;
        description
          "Indicate the devices support the MAP-E function. Devices
          advertise the map-e feature through the capability exchange
          mechanism when a NETCONF session is established.";
        container map-brs {
          description
            "A MAP enabled router managed by the service provider at
            the edge of a MAP domain.
            A Border Relay router has at least an IPv6-enabled interface
            and an IPv4 interface connected to the native IPv4 network.
            A MAP BR may also be referred to simply as a "BR" within the
            context of MAP.";
          list map-br {
            key "id";
            leaf id {
              type uint32;
            }
            leaf br-ipv6-addr {
              type inet:ipv6-address;
              description
                "The IPv6 address of the Border Router.";
            }
            container map-rule-table {
              uses map-rule-table;
            }
          }
        }
      }
    }

  /*
   * Operational state Data Nodes
   */

    container softwire-state {
      config false;
      description
        "The operational state data for concentrators in softwire. ";
      leaf enabled {
        type boolean;
        description
          "Indicate if the Softwire concentrator function is enabled/

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          disbaled.";
      }
      leaf name {
        type string;
        description
          "The name of the softwire concentrator.";
      }
      leaf description {
        type string;
        description
          "A textual description of the softwire concentrator.";
      }
      leaf tunnel-mtu {
        type uint32;
        description
          "The MTU of tunnel payload on the softwire concentrator.";
      }

      container lw4over6 {
        if-feature lw4over6;
        description
          "Indicate the device support the Lightweight 4over6 function.
          Device advertise the lw4over6 feature through the capability
          exchange mechanism when a NETCONF session is established.";
        container lwaftrs {
          description
            "An AFTR element (Address Family Transition Router element
            [RFC6333]), which supports Lightweight 4over6 extension.
            An lwAFTR is an IPv4-in-IPv6 tunnel endpoint which maintains
            per-subscriber address binding only and does not perform a
            NAPT44 function.";
          list lwaftr {
            key "id";
            leaf id {
              type uint32;
            }
            leaf lwaftr-ipv6-addr {
              type inet:ipv6-address;
              description
                "The IPv6 address of the lwAFTR.";
            }
            container binding-table {
              uses binding-table;
            }
          }
        }
      }
      container map-e {

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        if-feature map-e;
        description
          "Indicate the device support the MAP-E function. Device
          advertise the map-e feature through the capability exchange
          mechanism when a NETCONF session is established.";
        container map-brs {
          description
            "A MAP enabled router managed by the service provider at
            the edge of a MAP domain.
            A Border Relay router has at least an IPv6-enabled interface
            and an IPv4 interface connected to the native IPv4 network.
            A MAP BR may also be referred to simply as a "BR" within the
            context of MAP.";
          list map-br {
            key "id";
            leaf id {
              type uint32;
            }
            leaf br-ipv6-addr {
              type inet:ipv6-address;
              description
                "The IPv6 address of the Border Router.";
            }
            container map-rule-table {
              uses map-rule-table;
              leaf active-map-rule-num {
                type uint8;
                description
                "The number of map rules which are active.";
              }
            }
          }
        }
      }
    }
  }
  <CODE ENDS>

5.  Security Considerations

   TBD

6.  IANA Considerations

   TBD

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7.  Acknowledgements

   The authors would like to thank Lishan Li for her contributions to
   this work.

8.  References

8.1.  Normative References

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

   [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.

   [RFC6991]  Schoenwaelder, J., "Common YANG Data Types", RFC 6991,
              July 2013.

8.2.  Informative References

   [I-D.ietf-softwire-lw4over6]
              Cui, Y., Qiong, Q., Boucadair, M., Tsou, T., Lee, Y., and
              I. Farrer, "Lightweight 4over6: An Extension to the DS-
              Lite Architecture", draft-ietf-softwire-lw4over6-11 (work
              in progress), October 2014.

   [I-D.ietf-softwire-map]
              Troan, O., Dec, W., Li, X., Bao, C., Matsushima, S.,
              Murakami, T., and T. Taylor, "Mapping of Address and Port
              with Encapsulation (MAP)", draft-ietf-softwire-map-11
              (work in progress), October 2014.

   [I-D.ietf-softwire-map-dhcp]
              Mrugalski, T., Troan, O., Farrer, I., Perreault, S., Dec,
              W., Bao, C., leaf.yeh.sdo@gmail.com, l., and X. Deng,
              "DHCPv6 Options for configuration of Softwire Address and
              Port Mapped Clients", draft-ietf-softwire-map-dhcp-09
              (work in progress), October 2014.

   [RFC6333]  Durand, A., Droms, R., Woodyatt, J., and Y. Lee, "Dual-
              Stack Lite Broadband Deployments Following IPv4
              Exhaustion", RFC 6333, August 2011.

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Authors' Addresses

   Qi Sun
   Tsinghua University
   Beijing  100084
   P.R. China

   Phone: +86-10-6278-5822
   Email: sunqi@csnet1.cs.tsinghua.edu.cn

   Hao Wang
   Tsinghua University
   Beijing  100084
   P.R. China

   Phone: +86-10-6278-5822
   Email: wangh13@mails.tsinghua.edu.cn

   Yong Cui
   Tsinghua University
   Beijing  100084
   P.R. China

   Phone: +86-10-6260-3059
   Email: yong@csnet1.cs.tsinghua.edu.cn

   Ian Farrer
   Deutsche Telekom AG
   CTO-ATI,Landgrabenweg 151
   Bonn, NRW  53227
   Germany

   Email: ian.farrer@telekom.de

Sun, et al.              Expires April 23, 2015                [Page 16]