A YANG Data Model for Optical Transport Network Topology
draft-ietf-ccamp-otn-topo-yang-01

CCAMP Working Group                                             H. Zheng
Internet-Draft                                                    Z. Fan
Intended status: Standards Track                     Huawei Technologies
Expires: March 18, 2018                                        A. Sharma
                                                                  Google
                                                                  X. Liu
                                                                   Jabil
                                                              S. Belotti
                                                                   Nokia
                                                                   Y. Xu
                                                                   CAICT
                                                                 L. Wang
                                                            China Mobile
                                                     O. Gonzalez de Dios
                                                              Telefonica
                                                      September 14, 2017


        A YANG Data Model for Optical Transport Network Topology
                   draft-ietf-ccamp-otn-topo-yang-01

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 document 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.

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 https://datatracker.ietf.org/drafts/current/.



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   Internet-Drafts are draft documents valid for a maximum of six months
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Copyright Notice

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   document authors.  All rights reserved.

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   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 . . . . . . . . . . . . . . . . . . . . . .   6
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  11
   5.  Manageability Considerations  . . . . . . . . . . . . . . . .  11
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  11
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  12
   8.  Contributors  . . . . . . . . . . . . . . . . . . . . . . . .  12
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  13
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .  13
     9.2.  Informative References  . . . . . . . . . . . . . . . . .  13
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  14

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 [RFC7950].  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 document 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 document is defined in
   [I-D.ietf-netmod-yang-tree-diagrams].  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










































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   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 tpn-range?   string
       |  +--rw ts-range?   string
       +--rw tsg?                  identityref
       +--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 tpn-range?   string
       |  +--ro ts-range?   string
       +--ro tsg?                  identityref
       +--ro distance?             uint32
     augment /nd:networks/nd:network/nd:node/lnk:termination-point
     /tet:te/tet:config:
       +--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:
       +--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 document 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



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   links, are still applicable for describing an OTN topology and the
   model presented in this document 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 document re-uses some attributes defined in
   ietf-transport-types.yang, which is specified in
   [I-D.ietf-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@2017-09-14.yang"

   module ietf-otn-topology {
     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";
       revision-date 2017-06-10;
     }

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



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     organization
       "IETF CCAMP Working Group";
     contact
       "WG Web: <http://tools.ietf.org/wg/ccamp/>
        WG List: <mailto:ccamp@ietf.org>

        Editor: Haomian Zheng
                <mailto:zhenghaomian@huawei.com>

        Editor: Zheyu Fan
                <mailto:fanzheyu2@huawei.com>

        Editor: Anurag Sharma
                <mailto:ansha@google.com>

        Editor: Xufeng Liu
                <mailto:Xufeng_Liu@jabil.com>

        Editor: Sergio Belotti
                <mailto:sergio.belotti@nokia.com>

        Editor: Yunbin Xu
                <mailto:xuyunbin@ritt.cn>

        Editor: Lei Wang
                <mailto:wangleiyj@chinamobile.com>

        Editor: Oscar Gonzalez de Dios
                <mailto:oscar.gonzalezdedios@telefonica.com>";

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

     revision 2017-09-14 {
       description
         "Revision 0.4";
       reference
         "draft-ietf-ccamp-otn-topo-yang-01.txt";
     }

     /*
      * 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 "link attributes for OTN";

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



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           leaf tpn-range {
             type string {
               pattern "([1-9][0-9]{0,3}(-[1-9][0-9]{0,3})?"
                     + "(,[1-9][0-9]{0,3}(-[1-9][0-9]{0,3})?)*)";
             }
             description
               "A list of available tributary port number range
                between 1 and 9999.
                For example 1-20,25,50-1000";
             reference
               "RFC 7139: GMPLS Signaling Extensions for Control of
                Evolving G.709 Optical Transport Networks";
           }
         }
         leaf ts-range {
           type string {
             pattern "([1-9][0-9]{0,3}(-[1-9][0-9]{0,3})?"
                   + "(,[1-9][0-9]{0,3}(-[1-9][0-9]{0,3})?)*)";
           }
           description
             "A list of available tributary slot range
              between 1 and 9999.
              For example 1-20,25,50-1000";
           reference
             "RFC 7139: 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
           "RFC 7138: Traffic Engineering Extensions to OSPF for GMPLS
            Control of Evolving G.709 Optical Transport Networks";
       }
       leaf distance {
         type uint32;
         description "distance in the unit of kilometers";
       }
     }

     grouping otn-tp-attributes {
       description "tp attributes for OTN";
       list supported-payload-types {
         key "index";
         description



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           "Supported payload types of a TP. The payload type is defined
            as the generalized PIDs in GMPLS.";
         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";
         }
       }
     }

     /*
      * 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/otntopo: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/otntopo:otn-topology" {
         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/"
          + "otntopo:otn-topology" {
         description "Augment only for otn network.";
       }
       description "Augment link configuration";
       uses otn-link-attributes;



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     }

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

   <CODE ENDS>


4.  IANA Considerations

   TBD.

5.  Manageability Considerations

   TBD.

6.  Security Considerations

   The data following the model defined in this document is exchanged
   via, for example, the interface between an orchestrator and a
   transport network controller.  The security concerns mentioned in



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   [I-D.ietf-teas-yang-te-topo] for using ietf-te-topology.yang model
   also applies to this document.

   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, 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

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

   Victor Lopez
   Telefonica
   Email: victor.lopezalvarez@telefonica.com

   Yunbo Li
   China Mobile
   Email: liyunbo@chinamobile.com

   Dieter Beller
   Nokia
   Email: dieter.beller@nokia.com



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   Yanlei Zheng
   China Unicom
   Email: zhengyl@dimpt.com

9.  References

9.1.  Normative References

   [I-D.ietf-ccamp-otn-tunnel-model]
              zhenghaomian@huawei.com, z., Fan, Z., Sharma, A., Rao, R.,
              Belotti, S., Lopezalvarez, V., and Y. Li, "OTN Tunnel YANG
              Model", draft-ietf-ccamp-otn-tunnel-model-00 (work in
              progress), July 2017.

   [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-12 (work in progress), July 2017.

   [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,
              <https://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,
              <https://www.rfc-editor.org/info/rfc7138>.

   [RFC7950]  Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
              RFC 7950, DOI 10.17487/RFC7950, August 2016,
              <https://www.rfc-editor.org/info/rfc7950>.

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

9.2.  Informative References

   [I-D.ietf-ccamp-wson-yang]
              Lee, Y., Dhody, D., Zhang, X., Guo, A., Lopezalvarez, V.,
              King, D., Yoon, B., and R. Vilata, "A Yang Data Model for
              WSON Optical Networks", draft-ietf-ccamp-wson-yang-07
              (work in progress), July 2017.






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   [I-D.ietf-netmod-yang-tree-diagrams]
              Bjorklund, M. and L. Berger, "YANG Tree Diagrams", draft-
              ietf-netmod-yang-tree-diagrams-01 (work in progress), June
              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-05 (work in progress), July 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,
              <https://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


   Anurag Sharma
   Google
   1600 Amphitheatre Parkway
   Mountain View, CA  94043

   Email: ansha@google.com








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   Xufeng Liu
   Jabil

   Email: Xufeng_Liu@jabil.com


   Sergio Belotti
   Nokia

   Email: sergio.belotti@nokia.com


   Yunbin Xu
   CAICT

   Email: xuyunbin@ritt.cn


   Lei Wang
   China Mobile

   Email: wangleiyj@chinamobile.com


   Oscar Gonzalez de Dios
   Telefonica

   Email: oscar.gonzalezdedios@telefonica.com























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