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Versions: 00 01                                                         
I2RS Working Group                                           Xian Zhang
Internet-Draft                                              Baoquan Rao
Intended status: Standards Track                                 Huawei


Expires: August 13, 2015                             February 12, 2015




             A YANG Data Model for Layer 1 Network Topology

                draft-zhang-i2rs-l1-topo-yang-model-00.txt


Abstract

   This draft describes a YANG data model to manipulate the topologies
   of a layer 1 network. It is independent of data plan technologies
   and control plane protocols. It can be augmented to include
   technology-specific data, such as for Optical Transport Networks
   (OTN).

Status of this Memo

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

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

   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."

   The list of current Internet-Drafts can be accessed at
   http://www.ietf.org/ietf/1id-abstracts.txt.

   The list of Internet-Draft Shadow Directories can be accessed at
   http://www.ietf.org/shadow.html.

   This Internet-Draft will expire on August 13, 2015.

   Copyright Notice

   Copyright (c) 2015 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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

Table of Contents

   1. Introduction ................................................ 2
   2. Conventions used in this document............................ 3
   3. Terminology and Notations.................................... 3
   4. YANG Data Model for Layer 1 Topology .........................3
      4.1. YANG Tree ............................................. 3
         4.1.1. Notification.......................................5
      4.2. YANG Code ............................................. 5
   5. Security Considerations..................................... 18
   6. Manageability Considerations................................ 18
   7. IANA Considerations ........................................ 18
   8. Acknowledgements ........................................... 18
   9. References ................................................. 18
      9.1. Normative References.................................. 18
      9.2. Informative References................................ 19
   10. Contributors' Addresses.................................... 19
   11. Authors' Addresses .........................................19



1. Introduction

   This document defines a data model of a layer one network topology,
   using YANG [RFC6020]. The model can be used by an application via
   the I2RS interface [draft-ietf-i2rs-architecture], in the following
   ways (but not limited to):

     o to obtain a whole view of the network topology information of
   its interest;

      o to receive notifications with regard to the information of the
   change of the network topology of its interest;

      o to enforce the establishment/update of a network topology with
   the characteristic specified in the data model;



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   This model is confined to describe layer 1 networks, but it is data
   plane technology independent and can be augmented to specify the
   topology for networks such as Optical Transport networks (OTN),
   Synchronous Digital Network/ (SDH/SONET).

   [Editor's Note: The authors are aware that there are other drafts
   closely relating to this draft. Coordination works have been
   undergoing to get these drafts aligned. ]

2. Conventions used in this document

   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 RFC-2119 [RFC2119].

3. Terminology and Notations

   A simplified graphical representation of the data model is used in
   this document. The meaning of the symbols in the YANG data tree
   presented later in this draft is defined in [ietf-netmod-rfc6087bis].
   They are provided below for reference.

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

      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, "!"
   means a presence container, and "*" denotes a list and 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.

4. YANG Data Model for Layer 1 Topology

4.1. YANG Tree

   module: layer-one-topology
      +--rw layer-one-topology
         +--rw topology* [topology-id]
            +--rw topology-id            topology-id
            +--rw name?                  string
            +--rw supporting-topology* [topo-ref]


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            |  +--rw topo-ref    leafref
            +--rw node* [node-id]
            |  +--rw node-id                node-id
            |  +--rw interface* [interface-id]
            |  |  +--rw interface-id             interface-id
            |  |  +--rw adaptation-capability!
            |  +--rw connectivity-matrix* [id]
            |     +--rw id               uint32
            |     +--rw type?            enumeration
            |     +--rw in-interface* [interface-ref]
            |     |  +--rw interface-ref    leafref
            |     +--rw out-interface* [interface-ref]
            |     |  +--rw interface-ref    leafref
            |     +--rw dir?             enumeration
            +--rw link* [link-id]
               +--rw link-id            link-id
               +--rw local
               |  +--rw local-node?        leafref
               |  +--rw local-interface?   leafref
               +--rw remote
               |  +--rw remote-node?        leafref
               |  +--rw remote-interface?   leafref
               +--rw supporting-path* [supporting-path-index]
               |  +--rw supporting-path-index     uint32
               |  +--rw topo-ref?                 leafref
               |  +--rw server-path-identifier!
               |  +--rw server-path-srlg
               |     +--rw srlg-values* [srlg-value]
               |        +--rw srlg-value    uint32
               +--rw te-attributes
                  +--rw link-index?                       uint64
                  +--ro information-source?               enumeration
                  +--ro credibility-preference?           uint16
                  +--rw admin-status?                     enumeration
                  +--ro oper-status?                      enumeration
                  +--rw area-id?                          binary
                  +--rw max-link-bandwidth?               decimal64
                  +--rw unreserved-bandwidth* [priority]
                  |  +--rw priority     uint8
                  |  +--rw bandwidth?   decimal64
                  +--ro distance?                         uint32


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                  +--rw te-default-metric?                uint32
                  +--rw link-protection-type?             enumeration
                  +--rw interface-switching-capability* [switching-
   capability]
                  |  +--rw switching-capability switching-capabilities
                  |  +--rw encoding? encoding-types
                  |  +--rw max-lsp-bandwidth* [priority]
                  |  |  +--rw priority     uint8
                  |  |  +--rw bandwidth?   decimal64
                  |  +--rw switching-capability-specific-information!
                  +--rw srlg
                     +--rw srlg-values* [srlg-value]
                        +--rw srlg-value    uint32
4.1.1. Notification

   [TBD]

4.2. YANG Code

   <CODE BEGINS>

   module layer-one-topology {
     yang-version 1;

     namespace "urn:ietf:params:xml:ns:yang:layer-one-topology";
     prefix l1topo;

     import ietf-inet-types {
     prefix inet;
     }

     organization "Internet Engineering Task Force (IETF) I2RS WG";
     contact
       "ID-draft editor: zhang.xian@huawei.com";
     description
       "This module defines a data-plan technology/protocol independent
   Layer One topology data model.";

     revision 2015-02-11 {
       description
         "Initial version";

       reference
        "TBD: draft-zhang-i2rs-l1-topo-yang-model-00.txt";
     }


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     /*
      * Typedefs
      */

     typedef topology-id {
       type inet:uri;
     }

     typedef node-id {
       type inet:ip-address;
     }

     typedef interface-id {
       type union {
          type inet:ip-address; // IPv4 or IPv6 address
          type int32;          // Unnumbered
       }
       description
       "the identifier of an interface within a node, supporting both
   numbered/unumbered";
     }

     typedef link-id {
      type inet:ip-address; // IPv4 or IPv6 address
       description
       "the identifier of a link";
     }

     typedef switching-capabilities {
       type enumeration {
         enum "psc-1" {
           value 1;
           description
             "Packet-Switch Capable-1 (PSC-1)";
         }
         enum "evpl" {
           value 30;
           description
             "Ethernet Virtual Private Line (EVPL)";
         }

         enum "pbb-te"{
         value 40;
         description
           "802_1 PBB-TE";
         }


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         enum "l2sc" {
           value 51;
           description
             "Layer-2 Switch Capable (L2SC)";
         }
         enum "tdm" {
           value 100;
           description
             "Time-Division-Multiplex Capable (TDM)";
         }
         enum "otn-tdm" {
           value 110;
           description
             "OTN-TDM Capable";
         }
         enum "lsc" {
           value 150;
           description
             "Lambda-Switch Capable (LSC)";
         }
         enum "fsc" {
           value 200;
           description
             "Fiber-Switch Capable (FSC)";
         }
       }

       description
        "Switching capability of an interface.
        Only a subset of the above-mentioned values are applicable to
   Layer 1 network. Here it is included for completeness and will later
   be updated if a base model is augmented to create layer 1 network
   topology YANG data model.";

       reference
        "The definition of switching types, their values and the
   relevant RFCs (i.e., RFC3471, 4328) can be found at:
        http://www.iana.org/assignments/gmpls-sig-parameters/gmpls-
   sig-parameters.xhtml#gmpls-sig-parameters-3";
     }

     typedef encoding-types {
       type enumeration {
         enum "packet" {
           value 1;
           description


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             "Packet";
         }
         enum "ethernet" {
           value 2;
           description
              "Ethernet";
         }
         enum "pdh" {
           value 3;
           description
             "PDH";
         }
         enum "sdh-sonet" {
           value 5;
           description
             "SDH/SONET";
         }
         enum "digital-wrapper" {
           value 7;
           description
             "Digital Wrapper";
         }
         enum "lambda" {
           value 8;
           description
             "Lambda(photonic)";
         }
         enum "fiber" {
           value 9;
           description
             "Fiber";
         }
         enum "fiber-channel" {
           value 11;
           description
             "FiberChannel";
         }
         enum "oduk" {
           value 12;
           description
             "G.709 OKUk (Digital Path)";
         }
         enum "optical-channel" {
           value 13;
           description
             "G.709 Optical Channel";
         }


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         enum "line" {
           value 14;
           description
             "Line (e.g., 8B/10B)";
         }
       }
       description
         "The encoding type supported by an interface or link.
          Not all encoding types are applicable to Layer one network
   nodes. They are included here for completeness and will be updated
   if a base model is available to augment so as to build a layer-one
   specific YANG data model.";
       reference
        "The definition of encoding types, their values and the
   relevant RFCs (RFC3471, RFC4328, RFC6004) can be found at
   http://www.iana.org/assignments/gmpls-sig-parameters/gmpls-sig-
   parameters.xhtml#gmpls-sig-parameters-3";
     }

     /*
      * Groupings
      */

     grouping srlg-attribute {
       description
         "Shared Risk Link Group Attributes";
       reference
         "RFC 4203: OSPF Extensions in Support of Generalized Multi-
   Protocol Label Switching (GMPLS)";
       list srlg-values {
         key "srlg-value";
         leaf srlg-value {
           type uint32;
         }
       }
     }

     /*
      * Configuration data nodes
      */


     container layer-one-topology {
       list topology {
         key "topology-id";
         leaf topology-id {
           type topology-id;


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         }

         leaf name {
           type string;
         }

         list supporting-topology {
           key "topo-ref";
           leaf topo-ref {
             type leafref {
               path "/layer-one-topology/topology/topology-id";
             }
           description
            "a Layer-One network might be supported by a lower layer
   network and this is a pointer to the suporting topology if there is
   one";
           }
         }

         list node {
           key "node-id";
           leaf node-id {
             type node-id;
           }
           list interface {
             key "interface-id";
             leaf interface-id {
               type interface-id;
             }
             container adaptation-capability {
               presence "to define adaptation capability for different
   technologies.";
              description
                "TBD";
             }
           }
           list connectivity-matrix {
             key "id";

             description
              "This describes the connectivity contraints within a
   node in the network. It can  be one matrix or a set of matrixes.
   Further details, read the reference provided below.";
             reference
               "https://tools.ietf.org/html/draft-ietf-ccamp-general-
   constraint-encode-16 Section 2.1";



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             leaf id {
               type uint32;
             }
             leaf type {
               type enumeration {
                 enum fixed {
                   value 0;
                 }
                 enum dynamic {
                   value 1;
                 }
               }

               description
               "This field describes the attribute of a connectivity
   matrix, i.e., whether it is fixed or switched.";
             }
             list in-interface {
               key "interface-ref";

             description
                "This list describes a (sub)-set of ingoing-
   interfaces within a node that may have connectivity constraints.
              Note: directionality may not be relevant and it is
   decided by the dir parameter.";

               leaf interface-ref {
               type leafref {
                   path "/layer-one-
   topology/topology/node/interface/interface-id";
                 }
               }
             }
             list out-interface {
               key "interface-ref";

             description
              "This list describes a (sub)-set of ingoing-
   interfaces within a node that may have connectivity constraints.
              Note: directionality may not be relevant and it is
   decided by the dir parameter.";

               leaf interface-ref {
                 type leafref {
                   path "/layer-one-
   topology/topology/node/interface/interface-id";
                 }


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               }
             }
             leaf dir{
               type enumeration{
               enum "uni-dir"{
                 description
                   "the matrix is unidirectional.";
               }
               enum "bi-dir"{
                 description
                   "this matrix is bidirecdtional.";
               }
               }
             }
           }
         }

         list link {
         key "link-id";
         leaf link-id {
             type link-id;
             description
               "remaining issue: if there is no IP addresses
   associated with this link,
               what would be the key?";
         }

           container local {
            leaf local-node {
              type leafref {
               path "/l1topo:layer-one-topology/topology/node/node-id";
              }
            }
            leaf local-interface {
              type leafref {
               path "/l1topo:layer-one-
   topology/topology/node/interface/interface-id";
              }
            }
         }
         container remote {
            leaf remote-node {
              type leafref {
                 path "/l1topo:layer-one-topology/topology/node/node-
   id";
              }
            }


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            leaf remote-interface {
              type leafref {
               path "/l1topo:layer-one-
   topology/topology/node/interface/interface-id";
              }
            }
         }
         list supporting-path {
            key "supporting-path-index";
            leaf supporting-path-index {
              type uint32;
            }
            leaf topo-ref {
              type leafref {
               path "/l1topo:layer-one-topology/topology/topology-id";
              }
            }
            container server-path-identifier {
              presence "Define server path identifier.";
            }
            container server-path-srlg {
              uses srlg-attribute;
            }
         }

         container te-attributes {
            leaf link-index {
              type uint64;
            }
            leaf information-source {
             type enumeration {
               enum "unknown" {
                 description
                  "The source is unknown";
               }
               enum "locally-configured" {
                 description
                  "Configured TE link";
               }
               enum "ospfv2" {
                 description
                  "OSPFv2";
               }
               enum "ospfv3" {
                 description
                  "OSPFv3";
               }


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               enum "isis" {
                 description
                  "ISIS";
               }
              }
              config false;

              description
               "Indicates the source of the information about the link.
                remaining issue: if configuration of a link is allowed,
   what additional types are needed to add?";
            }
            leaf credibility-preference {
              type uint16;
              config false;
            }
            leaf admin-status {
              type enumeration {
                enum up {
                 value 1;
                 description
                   "up";
               }
               enum down {
                 value 2;
                 description
                   "down";
               }
               enum testing {
                 value 3;
                 description
                   "testing - in some test mode.";
               }
             }
             description
               "The adminstrative state of the link.";
             reference
              "RFC2863: The Interfaces Group MIB.";
           }
           leaf oper-status {
             type enumeration {
               enum up {
                 value 1;
                 description
                   "up";
               }
               enum down {


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                 value 2;
                 description
                   "down";
               }
               enum testing {
                 value 3;
                 description
                   "testing - in some test mode";
               }
               enum unknown {
                 value 4;
                 description
                   "unknown - status cannot be determined for some
   reason.";
               }
               enum dormant{
                 value 5;
               }
             }
             config false;
             description
               "The current operational state of the link.";
             reference
              "RFC2863: The Interfaces Group MIB.";
           }
           leaf area-id {
             type binary {
               length 1..13;
             }
             description
               "This object indicates the area identifier of the IGP,
   it can identify either a OSPF or ISIS area.";
              reference
              "RFC4920:  Crankback Signaling Extensions for MPLS and
   GMPLS RSVP-TE.";
           }

           leaf max-link-bandwidth {
             type decimal64 {
               fraction-digits 2;
             }
             description
              "the max bandwidth supported by this link";
           }

           list unreserved-bandwidth {
             key "priority";


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             max-elements "8";

             description
              "This describes the unreserved bandwidth (in
   Bytes/second) on a level basis ( level 0-7).";

             leaf priority {
               type uint8{
               range "0..7";
               }
             }
             leaf bandwidth {
               type decimal64 {
                 fraction-digits 2;
               }
             }
           }

           leaf distance {
            type  uint32;
            units "kilometers";

            config false;
            description
              "the distance this link spans.";
           }
           leaf te-default-metric {
             type uint32;
           }

           leaf link-protection-type {
             type enumeration {
                enum "extra-traffic" {
                 description "Extra traffic";
               }
                enum "unprotected" {
                 description "unprotected";
               }
               enum "shared" {
                 description "Shared";
               }
               enum "1-for-1" {
                 description "Dedicated one for one protection";
               }
               enum "1-plus-1" {
                 description "Dedicated one plus one protection";
               }


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               enum "enhanced" {
                 description "a protection type that is more reliable
   than Dedicated 1-plus-1, e.g., 4 fiber BLSR/MS-SPRING.";
               }
             }
             description
               "Link Protection Type configured for this link";
             reference
              "RFC3471: Generalized MUlti-Protocol Label Switching
   (GMPLS) Signaling Functional Description.";
           }
           list interface-Switching-capability {
             key "switching-capability";
             leaf switching-capability {
               type switching-capabilities;
             }
             leaf encoding {
               type encoding-types;
               description
                 "the encoding type supported by this link.";
             }
             list max-lsp-bandwidth {
               key "priority";
               max-elements "8";
               leaf priority {
                 type uint8 {
                   range "0..7";
                 }
               }
               leaf bandwidth {
                 type decimal64 {
                   fraction-digits 2;
                 }
               }
               description
                "remaining issue: to check how is used.";
             }
             container switching-capability-specific-information {
               presence "to define switch capability specific
   information for technology specific network (e.g., OTN).";
             }
           }
           container srlg {
             uses srlg-attribute;
           }
         }
       }


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     }
     }
   }
   <CODE ENDS>


5. Security Considerations

   The YANG data model defined in this draft itself does not introduce
   additional security concerns besides those mentioned in [draft-ietf-
   i2rs-architecture].

6. Manageability Considerations

   TBD.

7. IANA Considerations

   TBD.

8. Acknowledgements

   The initial YANG model specified in this draft is based on draft-
   clemm-i2rs-yang-network-topo but it is modified according to the
   features of the layer one networks.

   [Editor's note: Further modification of this data model will be
   seeking ways to get aligned by augmenting.]

   We would like to thank the authors of the above mentioned draft,
   especially Xufeng Liu, for his helpful discussion during the
   creation of this draft.

9. References

9.1. Normative References

   [RFC2119] S. Bradner, "Key words for use in RFCs to indicate
             requirements levels", RFC 2119, March 1997.

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




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   [ietf-netmod-rfc6087bis] Bierman, A., "Guidelines for Authors and
             Reviewers of YANG  Data Model Documents", draft-ietf-
             netmod-rfc6087bis-01, work in progress, October 2014.

9.2. Informative References

   [draft-ietf-i2rs-architecture] Atlas, A., Halpern, J., Hares, S.,
             Ward, D., Nadeau T., "An Architecture for the Interface to
             the Routing System", draft-ietf-i2rs-architecture-08, work
             in progress, January 2015;

   [draft-clemm-i2rs-yang-network-topo] Clemm A., Medved J., Tkacik T.,
   Varga R., et al, "A YANG Data Model for Network Topologies", draft-
   clemm-i2rs-yang-network-topo-01, work in progress, October 2014;

10. Contributors' Addresses

11. Authors' Addresses

   Xian Zhang
   Huawei Technologies
   Email: zhang.xian@huawei.com

   Baoquan Rao
   Huawei Technologies
   raobaoquan@huawei.com






















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