CCAMP Working Group                                             H. Zheng
Internet-Draft                                                    Z. Fan
Intended status: Standards Track                     Huawei Technologies
Expires: October 27, 2017                                      A. Sharma
                                                                  Google
                                                                  X. Liu
                                                                   Jabil
                                                          April 25, 2017


        A YANG Data Model for Optical Transport Network Topology
                   draft-zhang-ccamp-l1-topo-yang-07

Abstract

   A transport network is a server-layer network designed to provide
   connectivity services for a client-layer network to carry the client
   traffic transparently across the server-layer network resources.  A
   transport network can be constructed from equipments utilizing any of
   a number of different transport technologies such as the evolving
   Optical Transport Networks (OTN) or packet transport as provided by
   the MPLS-Transport Profile (MPLS-TP).

   This draft describes a YANG data model to describe the topologies of
   an Optical Transport Network (OTN).  It is independent of control
   plane protocols and captures topological and resource related
   information pertaining to OTN.  This model enables clients, which
   interact with a transport domain controller via a REST interface, for
   OTN topology related operations such as obtaining the relevant
   topology resource information.

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/.





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   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 October 27, 2017.

Copyright Notice

   Copyright (c) 2017 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  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Terminology and Notations . . . . . . . . . . . . . . . . . .   3
   3.  YANG Data Model for OTN Topology  . . . . . . . . . . . . . .   4
     3.1.  the YANG Tree . . . . . . . . . . . . . . . . . . . . . .   4
     3.2.  Explanation of the OTN Topology Data Model  . . . . . . .   5
     3.3.  The YANG Code . . . . . . . . . . . . . . . . . . . . . .   5
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  13
   5.  Manageability Considerations  . . . . . . . . . . . . . . . .  13
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  13
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  13
   8.  Contributors  . . . . . . . . . . . . . . . . . . . . . . . .  13
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  14
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .  14
     9.2.  Informative References  . . . . . . . . . . . . . . . . .  15
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  15

1.  Introduction

   A transport network is a server-layer network designed to provide
   connectivity services for a client-layer network to carry the client
   traffic transparently across the server-layer network resources.  A
   transport network can be constructed of equipments utilizing any of a
   number of different transport technologies such as the Optical




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   Transport Networks (OTN) or packet transport as provided by the MPLS-
   Transport Profile (MPLS-TP).

   This document defines a data model of an OTN network topology, using
   YANG [RFC6020].  The model can be used by an application exposing to
   a transport controller via a REST interface.  Furthermore, it can be
   used by an application for the following purposes (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 change of
      the OTN topology;

   o  To enforce the establishment and update of a network topology with
      the characteristic specified in the data model, e.g., by a client
      controller;

   The YANG model defined in this draft is independent of control plane
   protocols and captures topology related information pertaining to an
   Optical Transport Networks (OTN)-electrical layer, as the scope
   specified by [RFC7062] and [RFC7138].  Furthermore, it is not a
   stand-alone model, but augmenting from the TE topology YANG model
   defined in [I-D.ietf-teas-yang-te-topo].

   Optical network technologies, including fixed Dense Wavelength
   Switched Optical Network (WSON) and flexible optical networks
   (a.k.a., flexi-grid networks), are covered in
   [I-D.ietf-ccamp-wson-yang] and [I-D.vergara-ccamp-flexigrid-yang],
   respectively.

2.  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
   [I-D.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.





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   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.

3.  YANG Data Model for OTN Topology

3.1.  the YANG Tree


   module: ietf-otn-topology
   augment /nd:networks/nd:network/nd:network-types/tet:te-topology:
      +--rw otn-topology!
   augment /nd:networks/nd:network:
      +--rw name?   string
   augment /nd:networks/nd:network/nd:node:
      +--rw name?   string
   augment /nd:networks/nd:network/lnk:link/tet:te/tet:config:
      +--rw available-odu-info* [priority]
      |  +--rw priority    uint8
      |  +--rw odulist* [odu-type]
      |     +--rw odu-type    identityref
      |     +--rw number?     uint16
      +--rw distance?             uint32
   augment /nd:networks/nd:network/lnk:link/tet:te/tet:state:
      +--ro available-odu-info* [priority]
      |  +--ro priority    uint8
      |  +--ro odulist* [odu-type]
      |     +--ro odu-type    identityref
      |     +--ro number?     uint16
      +--ro distance?             uint32
   augment /nd:networks/nd:network/nd:node/lnk:termination-point
   /tet:te/tet:config:
      +--rw client-facing?             empty
      +--rw tpn?                       uint16
      +--rw tsg?                       identityref
      +--rw protocol-type?             identityref
      +--rw adaptation-type?           adaptation-type
      +--rw sink-adapt-active?         boolean
      +--rw source-adapt-active?       boolean
      +--rw tributary-slots
      |  +--rw values*   uint8
      +--rw supported-payload-types* [index]
         +--rw index           uint16
         +--rw payload-type?   string
   augment /nd:networks/nd:network/nd:node/lnk:termination-point/
   tet:te/tet:state:



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      +--ro client-facing?             empty
      +--ro tpn?                       uint16
      +--ro tsg?                       identityref
      +--ro protocol-type?             identityref
      +--ro adaptation-type?           adaptation-type
      +--ro sink-adapt-active?         boolean
      +--ro source-adapt-active?       boolean
      +--ro tributary-slots
      |  +--ro values*   uint8
      +--ro supported-payload-types* [index]
         +--ro index           uint16
         +--ro payload-type?   string


3.2.  Explanation of the OTN Topology Data Model

   As can be seen, from the data tree shown in Section 3.1, the YANG
   module presented in this draft augments from a more generic Traffic
   Engineered (TE) network topology data model, i.e., the ietf-te-
   topology.yang as specified in [I-D.ietf-teas-yang-te-topo].  The
   entities and their attributes, such as node, termination points and
   links, are still applicable for describing an OTN topology and the
   model presented in this draft only specifies with technology-specific
   attributes/information.  For example, if the data plane complies with
   ITU-T G.709 (2012) standards, the switching-capability and encoding
   attributes MUST be filled as OTN-TDM and G.709 ODUk(Digital Path)
   respectively.

   Note the model in this draft re-uses some attributes defined in ietf-
   transport-types.yang, which is specified in
   [I-D.sharma-ccamp-otn-tunnel-model].

   One of the main augmentations in this model is that it allows to
   specify the type of ODU container and the number a link can support
   per priority level.  For example, for a ODU3 link, it may advertise
   32*ODU0, 16*ODU1, 4*ODU2 available, assuming only a single priority
   level is supported.  If one of ODU2 resource is taken to establish a
   ODU path, then the availability of this ODU link is updated as
   24*ODU0, 12*ODU1, 3*ODU2 available.  If there are equipment hardware
   limitations, then a subset of potential ODU type SHALL be advertised.
   For instance, an ODU3 link may only support 4*ODU2.

3.3.  The YANG Code


   <CODE BEGINS> file "ietf-otn-topology@2017-04-25.yang"

   module ietf-otn-topology {



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    yang-version 1.1;

    namespace "urn:ietf:params:xml:ns:yang:ietf-otn-topology";
    prefix "otntopo";

    import ietf-network {
     prefix "nd";
    }

    import ietf-network-topology {
     prefix "lnk";
    }

    import ietf-te-topology {
     prefix "tet";
    }

    import ietf-transport-types {
     prefix "tran-types";
    }

    organization
     "Internet Engineering Task Force (IETF) CCAMP WG";
    contact
     "
     WG List: <mailto:ccamp@ietf.org>

     ID-draft editor:
      Haomian Zheng (zhenghaomian@huawei.com);
      Zheyu Fan (fanzheyu2@huawei.com);
      Anurag Sharma (ansha@google.com);
      Xufeng Liu (Xufeng_Liu@jabil.com)
     ";

    description
     "This module defines a protocol independent Layer 1/ODU
     topology data model.";

    revision 2017-04-25 {
     description
      "Revision 0.3";
     reference
      "draft-zhang-ccamp-l1-topo-yang-07.txt";
    }

    /*
    typedef
    */



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    typedef adaptation-type {
     type enumeration {
      enum CBR {
       description "Constant Bit Rate.";
      }
      enum ATMvp {
       description "ATM VP.";
      }
      enum GFP {
       description "Generic Framing Procedure.";
      }
      enum NULL {
       description "NULL";
      }
      enum PRBS {
       description "Pseudo Random Binary Sequence";
      }
      enum RSn {
       description "SDH/SONET section";
      }
      enum ODUj-21 {
       description "ODU payload type 21";
      }
      enum ETHERNET_PP-OS {
       description "ETHERNET_PP-OS, for ODU 2 only";
      }
      enum CBRx {
       description "CBRx(0.. 1.25G), for ODU0 only";
      }
      enum ODU {
       description "Optical Data Unit";
      }
     }

     description
      "Defines a type representing the adaptation type
      on the termination point.";
    }


    /*
    Groupings
    */

    grouping otn-topology-type {
     container otn-topology {
      presence "indicates a topology type of Optical
       Transport Network (OTN)-electrical layer.";



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       description "otn topology type";
     }
     description "otn-topology-type";
    }

    grouping otn-topology-attributes {
     leaf name {
      type string;
      description "the topology name";
     }
     description "name attribute for otn topology";
    }

    grouping otn-node-attributes {
     description "otn-node-attributes";
     leaf name {
      type string;
      description "a name for this node.";
     }
    }

    grouping otn-link-attributes {
     description "otn link attributes";

     list available-odu-info{
      key "priority";
      max-elements "8";

      description
       "List of ODU type and number on this link";
      leaf priority {
       type uint8 {
        range "0..7";
       }
       description "priority";
      }

      list odulist {
       key "odu-type";

       description
        "the list of available ODUs per priority level";

       leaf odu-type {
        type identityref{
         base tran-types:tributary-protocol-type;
        }
        description "the type of ODU";



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       }

       leaf number {
        type uint16;
        description "the number of odu type supported";
       }
      }
     }

     leaf distance {
      type uint32;
      description "distance in the unit of kilometers";
     }
   }

    grouping otn-tp-attributes {
     description "otn-tp-attributes";

     leaf client-facing {
      type empty;
      description
       "if present, it means this tp is a client-facing tp.
       adding/dropping client signal flow.";
     }

     leaf tpn {
      type uint16 {
       range "0..4095";
      }
      description
       "Tributary Port Number. Applicable in case of mux services.";
       reference
      "RFC7139: GMPLS Signaling Extensions for Control of Evolving
      G.709 Optical Transport Networks.";
     }

     leaf tsg {
      type identityref {
       base tran-types:tributary-slot-granularity;
      }
      description "Tributary slot granularity.";
      reference
      "G.709/Y.1331, February 2012: Interfaces for the Optical
      Transport Network (OTN)";
     }

     leaf protocol-type {
      type identityref {



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       base tran-types:tributary-protocol-type;
      }
      description "Protocol type for the Termination Point.";
     }

     leaf adaptation-type {
      type adaptation-type;
      description
      "This attribute indicates the type of the supported
      adaptation function at the termination point.";
      reference
      "G.874.1, January 2002: Optical transport network (OTN):
      Protocol-neutral management information model for the
      network element view.";
     }

     leaf sink-adapt-active {
      type boolean;
      description
      "This attribute allows for activation or deactivation of
      the sink adaptation function. The value of TRUE means active.";

      reference
      "G.874.1, January 2002: Optical transport network (OTN):
      Protocol-neutral management information model for the
      network element view ";
     }

     leaf source-adapt-active {
      type boolean;
      description
      "This attribute allows for activation or deactivation of
      the sink adaptation function. The value of TRUE
      means active.";
      reference
      "G.874.1, January 2002: Optical transport network (OTN):
      Protocol-neutral management information model for
      the network element view ";
     }

      container tributary-slots {
       description
       "A list of tributary slots used by the ODU
       Termination Point.";
       leaf-list values {
        type uint8;
        description
        "Tributary slot value.";



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        reference
        "G.709/Y.1331, February 2012: Interfaces for the
        Optical Transport Network (OTN)";
       }
     }

     list supported-payload-types{
      key "index";

      description "supported payload types of a TP";

      leaf index {
       type uint16;
       description "payload type index";
      }

      leaf payload-type {
       type string;
       description "the payload type supported by this client
       tp";
       reference
       "http://www.iana.org/assignments/gmpls-sig-parameters
       /gmpls-sig-parameters.xhtml
       not: the payload type is defined as the generalized PIDs
       in GMPLS.";
      }
     }
    }


    /*
    * Data nodes
    */
    augment "/nd:networks/nd:network/nd:network-types/tet:te-topology" {
     uses otn-topology-type;
     description "augment network types to include otn newtork";
    }

    augment "/nd:networks/nd:network" {
     when "nd:network-types/tet:te-topology/otn-topology" {
      description "Augment only for otn network";
     }
     uses otn-topology-attributes;
     description "Augment network configuration";
    }

    augment "/nd:networks/nd:network/nd:node" {
     when "../nd:network-types/tet:te-topology/otn-topology" {



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      description "Augment only for otn network";
     }
     description "Augment node configuration";
     uses otn-node-attributes;
    }

    augment "/nd:networks/nd:network/lnk:link/tet:te/tet:config" {
     when "../../../nd:network-types/tet:te-topology/otn-topology" {
      description "Augment only for otn network.";
     }
     description "Augment link configuration";

     uses otn-link-attributes;
    }

    augment "/nd:networks/nd:network/lnk:link/tet:te/tet:state" {
     when "../../../nd:network-types/tet:te-topology/otn-topology" {
      description "Augment only for otn network.";
     }
     description "Augment link state";

     uses otn-link-attributes;
    }

    augment "/nd:networks/nd:network/nd:node/"
     +"lnk:termination-point/tet:te/tet:config" {
     when "../../../../nd:network-types/tet:te-topology/otn-topology" {
      description "Augment only for otn network";
     }
     description "OTN TP attributes config in a ODU topology.";
     uses otn-tp-attributes;
    }

    augment "/nd:networks/nd:network/nd:node/"
     +"lnk:termination-point/tet:te/tet:state" {
     when "../../../../nd:network-types/tet:te-topology/otn-topology" {
      description "Augment only for otn network";
     }
     description "OTN TP attributes state in a ODU topology.";
     uses otn-tp-attributes;
    }
   }

   <CODE ENDS>







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4.  IANA Considerations

   TBD.

5.  Manageability Considerations

   TBD.

6.  Security Considerations

   The data following the model defined in this draft is exchanged via,
   for example, the interface between an orchestrator and a transport
   network controller.  The security concerns mentioned in
   [I-D.ietf-teas-yang-te-topo] for using ietf-te-topology.yang model
   also applies to this draft.

   The YANG module defined in this document can be accessed via the
   RESTCONF protocol defined in [RFC8040], or maybe via the NETCONF
   protocol [RFC6241].

   There are a number of data nodes defined in the YANG module which are
   writable/creatable/deletable (i.e., config true, which is the
   default).  These data nodes may be considered sensitive or vulnerable
   in some network environments.  Write operations (e.g., POST) to these
   data nodes without proper protection can have a negative effect on
   network operations.

   Editors note: to list specific subtrees and data nodes and their
   sensitivity/vulnerability.

7.  Acknowledgements

   We would like to thank Igor Bryskin, Zhe Liu, Dieter Beller and
   Daniele Ceccarelli for their comments and discussions.

8.  Contributors

   Baoquan Rao
   Huawei Technologies
   Email: raobaoquan@huawei.com

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

   Sergio Belotti
   Nokia
   Email: sergio.belotti@nokia.com



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   Huub van Helvoort
   Hai Gaoming BV
   the Netherlands
   Email: huubatwork@gmail.com

9.  References

9.1.  Normative References

   [I-D.ietf-teas-yang-te-topo]
              Liu, X., Bryskin, I., Beeram, V., Saad, T., Shah, H., and
              O. Dios, "YANG Data Model for TE Topologies", draft-ietf-
              teas-yang-te-topo-08 (work in progress), March 2017.

   [I-D.sharma-ccamp-otn-tunnel-model]
              Zhang, X., xiangkun, x., ansharma@infinera.com, a., and R.
              Rao, "OTN Tunnel YANG Model", draft-sharma-ccamp-otn-
              tunnel-model-01 (work in progress), March 2017.

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

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

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

   [RFC7138]  Ceccarelli, D., Ed., Zhang, F., Belotti, S., Rao, R., and
              J. Drake, "Traffic Engineering Extensions to OSPF for
              GMPLS Control of Evolving G.709 Optical Transport
              Networks", RFC 7138, DOI 10.17487/RFC7138, March 2014,
              <http://www.rfc-editor.org/info/rfc7138>.

   [RFC8040]  Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
              Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
              <http://www.rfc-editor.org/info/rfc8040>.








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9.2.  Informative References

   [I-D.ietf-ccamp-wson-yang]
              Lee, Y., Dhody, D., Zhang, X., Guo, A., Lopezalvarez, V.,
              King, D., and B. Yoon, "A Yang Data Model for WSON Optical
              Networks", draft-ietf-ccamp-wson-yang-05 (work in
              progress), February 2017.

   [I-D.ietf-netmod-rfc6087bis]
              Bierman, A., "Guidelines for Authors and Reviewers of YANG
              Data Model Documents", draft-ietf-netmod-rfc6087bis-12
              (work in progress), March 2017.

   [I-D.vergara-ccamp-flexigrid-yang]
              Madrid, U., Perdices, D., Lopezalvarez, V., Dios, O.,
              King, D., Lee, Y., and G. Galimberti, "YANG data model for
              Flexi-Grid Optical Networks", draft-vergara-ccamp-
              flexigrid-yang-04 (work in progress), March 2017.

   [RFC7062]  Zhang, F., Ed., Li, D., Li, H., Belotti, S., and D.
              Ceccarelli, "Framework for GMPLS and PCE Control of G.709
              Optical Transport Networks", RFC 7062,
              DOI 10.17487/RFC7062, November 2013,
              <http://www.rfc-editor.org/info/rfc7062>.

Authors' Addresses

   Haomian Zheng
   Huawei Technologies
   F3 R&D Center, Huawei Industrial Base, Bantian, Longgang District
   Shenzhen, Guangdong  518129
   P.R.China

   Email: zhenghaomian@huawei.com


   Zheyu Fan
   Huawei Technologies
   F3 R&D Center, Huawei Industrial Base, Bantian, Longgang District
   Shenzhen, Guangdong  518129
   P.R.China

   Email: fanzheyu2@huawei.com








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   Anurag Sharma
   Google
   1600 Amphitheatre Parkway
   Mountain View, CA  94043

   Email: ansha@google.com


   Xufeng Liu
   Jabil

   Email: Xufeng_Liu@jabil.com







































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