Internet DRAFT - draft-ietf-ccamp-l1csm-yang

draft-ietf-ccamp-l1csm-yang







CCAMP Working Group                                               Y. Lee
Internet-Draft                                                      SKKU
Intended status: Standards Track                                  K. Lee
Expires: March 12, 2020                                    Korea Telecom
                                                                H. Zheng
                                                                D. Dhody
                                                     Huawei Technologies
                                                     O. Gonzalez de Dios
                                                              Telefonica
                                                           D. Ceccarelli
                                                                Ericsson
                                                       September 9, 2019


      A YANG Data Model for L1 Connectivity Service Model (L1CSM)
                     draft-ietf-ccamp-l1csm-yang-10

Abstract

   This document provides a YANG data model for Layer 1 Connectivity
   Service Model (L1CSM).  The intent of this document is to provide a
   Layer 1 service model exploiting YANG data model, which can be
   utilized by a customer network controller to initiate a service
   request connectivity as well as retrieving service states toward a
   Layer 1 network controller communicating with its customer network
   controller.  This YANG model is NMDA-compliant.

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/.

   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 March 12, 2020.








Lee, et al.              Expires March 12, 2020                 [Page 1]

Internet-Draft     A YANG Data Model for Layer 1 Types    September 2019


Copyright Notice

   Copyright (c) 2019 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
   (https://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.  Deployment Scenarios  . . . . . . . . . . . . . . . . . .   3
     1.2.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   6
     1.3.  Tree Diagram  . . . . . . . . . . . . . . . . . . . . . .   6
     1.4.  Prefixes in Data Node Names . . . . . . . . . . . . . . .   6
   2.  Definitions . . . . . . . . . . . . . . . . . . . . . . . . .   7
   3.  L1CSM YANG Model (Tree Structure) . . . . . . . . . . . . . .   7
   4.  L1CSM YANG Code . . . . . . . . . . . . . . . . . . . . . . .   8
   5.  JSON Example  . . . . . . . . . . . . . . . . . . . . . . . .  12
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  14
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  14
   8.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  15
   9.  Contributors  . . . . . . . . . . . . . . . . . . . . . . . .  15
   10. References  . . . . . . . . . . . . . . . . . . . . . . . . .  15
     10.1.  Normative References . . . . . . . . . . . . . . . . . .  15
     10.2.  Informative References . . . . . . . . . . . . . . . . .  16
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  17

1.  Introduction

   This document provides a YANG data model for L1VPN Connectivity
   Service Model (L1CSM) which can be classified as Network Service YANG
   module per [RFC8199].  The intent of this document is to provide a
   transport service model exploiting YANG data model, which can be
   utilized by a client network controller to initiate a service request
   connectivity request as well as retrieving service states toward a
   transport network controller communicating with the client controller
   via a NETCONF [RFC8341] or a RESTCONF [RFC8040] interface.

   [RFC4847] provides a framework and service level requirements for
   Layer 1 Virtual Private Networks (L1VPNs).  It classifies service



Lee, et al.              Expires March 12, 2020                 [Page 2]

Internet-Draft     A YANG Data Model for Layer 1 Types    September 2019


   models as management-based service model, signaling-based service
   model (Basic Mode) and signaling and routing service model (Enhanced
   Mode).

   In the management-based service model, customer management systems
   and provider management systems communicate with each other.
   Customer management systems access provider management systems to
   request layer 1 connection setup/deletion between a pair of CEs.
   Customer management systems may obtain additional information, such
   as resource availability information and monitoring information, from
   provider management systems.  There is no control message exchange
   between a CE and PE.

   In the signaling-based service model (Basic Model), the CE-PE
   interface's functional repertoire is limited to path setup signaling
   only.  In the Signaling and routing service model (Enhanced Mode),
   the CE-PE interface provides the signaling capabilities as in the
   Basic Mode, plus permits limited exchange of information between the
   control planes of the provider and the customer to help such
   functions as discovery of customer network routing information (i.e.,
   reachability or TE information in remote customer sites), or
   parameters of the part of the provider's network dedicated to the
   customer.

   The primary focus of this document is to describe L1CS YANG model
   required for the instantiation of point-to-point L1VPN service.  A
   L1VPN is a service offered by a core layer 1 network to provide layer
   1 connectivity between two or more customer sites where the customer
   has some control over the establishment and type of the connectivity.

   The data model presented in Section 3 is in consistent with [MEF63].
   The data model includes configuration and state data according to the
   new Network Management Datastore Architecture [RFC8342].

1.1.  Deployment Scenarios

   Figure 1 depicts a deployment scenario of the L1VPN SDN control-based
   service model for an external customer instantiating L1 point-to-
   point connectivity to the provider.












Lee, et al.              Expires March 12, 2020                 [Page 3]

Internet-Draft     A YANG Data Model for Layer 1 Types    September 2019


                             +------------+
                             |  Customer  |
                             |   Service  |
                             |Orchestrator|
                             +------------+
                                    |
                      .. .. .. .. ..|.. .. .. .. .. ..
                     :                          |                 :
                     :     +--------------------+     :
                     :     |                    |     :
                     :     |    +----------+    |     :
                     :     |    | Network  |    |     :
                     :     |    |   SDN    |    |     :
                     :     |    |Controller|    |     :
                     :     |    |/NMS/EMS  |    |     :
                     :     |    +----------+    |     :
                     :     |                    |     :
                     :     |                    |     :
           +----+    :   +----+    +----+    +----+   :   +----+
           | CE |----:---| PE |----| P  |----| PE |---:---| CE |
           +----+    :   +----+    +----+    +----+   :   +----+
                     :     |                    |     :
                     :     |                    |     :
                     :     +--------------------+     :
                     :     |                    |     :
                     :     |<-Provider network->|     :

                 Customer                          Customer
                 Interface                         Interface



   Figure 1: L1VPN SDN Controller/EMS/NMS-Based Service Model: External
                                 Customer

   With this scenario, the customer service orchestrator interfaces with
   the network SDN controller of the provider using Customer Service
   Model as defined in [RFC8309].

   Figure 2 depicts another deployment scenario for internal customer
   (e.g., higher-layer service management department(s)) interfacing the
   layer 1 transport network department.  With this scenario, a multi-
   service backbone is characterized such that each service department
   of a provider (e.g., L2/3 services) that receives the same provider's
   L1VPN service provides a different kind of higher-layer service.  The
   customer receiving the L1VPN service (i.e., each service department)
   can offer its own services, whose payloads can be any layer (e.g.,
   ATM, IP, TDM).  The layer 1 transport network and each service



Lee, et al.              Expires March 12, 2020                 [Page 4]

Internet-Draft     A YANG Data Model for Layer 1 Types    September 2019


   network belong to the same organization, but may be managed
   separately.  The Service SDN Controller is the control/management
   entity owned by higher-layer service department (e.g., L2/3 VPN)
   whereas the Network SDN Controller is the control/management entity
   responsible for Layer 1 connectivity service.  The CEs in Figure 2
   are L2/3 devices that interface with L1 PE devices.


                                   +----------+
                                   | Service  |
                                   |   SDN    |
                                   |Controller|
                                   |/EMS/NMS  |
                                   | for L2/3 |
                                   +----------+
                                        |
                                        |
                                        |
                           +--------------------+
                           |                    |
                           |    +----------+    |
                           |    | Network  |    |
                           |    |   SDN    |    |
                           |    |Controller|    |
                           |    |/EMS/NMS  |    |
                           |    | for L1VPN|    |
                           |    +----------+    |
                           |                    |
                           |                    |
           +----+        +----+    +----+    +----+      +----+
           | CE |--------| PE |----| P  |----| PE |------| CE |
           +----+        +----+    +----+    +----+      +----+
              |            |                    |          |
              |            |                    |          |
              |            +--------------------+          |
              |            |                    |          |
              |            |<------------------>|          |
              |               Provider Network             |
              |                  For Layer 1               |
              |<------------------------------------------>|
                             Provider Network for L2/3



   Figure 2: L1VPN SDN Controller/EMS/NMS-Based Service Model: Internal
                                 Customer





Lee, et al.              Expires March 12, 2020                 [Page 5]

Internet-Draft     A YANG Data Model for Layer 1 Types    September 2019


   The benefit is that the same layer 1 transport network resources are
   shared by multiple services.  A large capacity backbone network (data
   plane) can be built economically by having the resources shared by
   multiple services usually with flexibility to modify topologies,
   while separating the control functions for each service department.
   Thus, each customer can select a specific set of features that are
   needed to provide their own service [RFC4847].

1.2.  Terminology

   Refer to [RFC4847] and [RFC5253] for the key terms used in this
   document.

   The following terms are defined in [RFC7950] and are not redefined
   here:

   o  client

   o  server

   o  augment

   o  data model

   o  data node

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

   o  configuration data

   o  state data

   The terminology for describing YANG data models is found in
   [RFC7950].

1.3.  Tree Diagram

   A simplified graphical representation of the data model is used in
   Section 3 of this this document.  The meaning of the symbols in these
   diagrams is defined in [RFC8340].

1.4.  Prefixes in Data Node Names

   In this document, names of data nodes and other data model objects
   are prefixed using the standard prefix associated with the
   corresponding YANG imported modules.  The module ietf-layer1-types




Lee, et al.              Expires March 12, 2020                 [Page 6]

Internet-Draft     A YANG Data Model for Layer 1 Types    September 2019


   specified in [I-D.ietf-ccamp-layer1-types] and ietf-yang-types
   specified in [RFC6991] are imported in this module.


    +-------------+-------------------+------------------------------+
    | Prefix      | YANG module       |         Reference            |
    +-------------+-------------------+------------------------------+
    | l1csm       | ietf-l1csm        | [RFC XXXX]                   |
    | layer1-types|ietf-layer1-types  | [I-D.ietf-ccamp-layer1-types]|
    | yang        | ietf-yang-types   | [RFC6991]                    |
    +-------------+-------------------+------------------------------+


   Note: The RFC Editor will replace XXXX with the number assigned to
   the RFC once this draft becomes an RFC.

2.  Definitions

   L1VC Layer 1 Virtual Connection

   SLS Service Level Specification

   UNI User Network Interface

   PE Provider Edge

   CE Customer Edge

   EP End Point

   P Protocol

   C Coding

   O Optical Interface

3.  L1CSM YANG Model (Tree Structure)














Lee, et al.              Expires March 12, 2020                 [Page 7]

Internet-Draft     A YANG Data Model for Layer 1 Types    September 2019


      module: ietf-l1csm
       +--rw l1-connectivity
          +--rw access
          |  +--rw unis
          |     +--rw uni* [id]
          |        +--rw id                   string
          |        +--rw protocol?            identityref
          |        +--rw coding?              identityref
          |        +--rw optical-interface?   identityref
          +--rw services
             +--rw service* [service-id]
                +--rw service-id            string
                +--rw endpoint-1
                |  +--rw id     string
                |  +--rw uni    -> /l1-connectivity/access/unis/uni/id
                +--rw endpoint-2
                |  +--rw id     string
                |  +--rw uni    -> /l1-connectivity/access/unis/uni/id
                +--rw start-time?           yang:date-and-time
                +--rw time-interval?        int32
                +--rw performance-metric*   identityref


4.  L1CSM YANG Code


  <CODE BEGINS>file "ietf-l1csms@2019-09-09.yang"
  module ietf-l1csm {
    yang-version 1.1;
    namespace "urn:ietf:params:xml:ns:yang:ietf-l1csm";
    prefix "l1csm";

    import ietf-yang-types {
      prefix "yang";
    }

    import ietf-layer1-types {
      prefix "layer1-types";
    }

    organization
      "Internet Engineering Task Force (IETF) CCAMP WG";

    contact

      "Editor: Y. Lee (younglee_tx@gmail.com)
       Editor: K. Lee (kwangkoog.lee@kt.com)
       Editor: H. Zheng (zhenghaomian@huawei.com)



Lee, et al.              Expires March 12, 2020                 [Page 8]

Internet-Draft     A YANG Data Model for Layer 1 Types    September 2019


       Editor: D. Dhody (dhruv.ietf@gmail.com)
       Editor: O. G. de-Dios (oscar.gonzalezdedios@telefonica.com)
       Editor: D. Ceccarelli (daniele.ceccarelli@ericsson.com)";


    description
      "This module describes L1 connectivity service based on MEF 63:
           Subscriber Layer 1 Service Attribute Technical Specification.
           Refer to MEF 63 for all terms and the original references
       used in the module.

       Copyright (c) 2019 IETF Trust and the persons identified as
       authors of the code.  All rights reserved.
       Redistribution and use in source and binary forms, with or
       without modification, is permitted pursuant to, and subject
       to the license terms contained in, the Simplified BSD
       License set forth in Section 4.c of the IETF Trust's Legal
       Provisions Relating to IETF Documents
       (http://trustee.ietf.org/license-info).

       This version of this YANG module is part of RFC XXXX; see
       the RFC itself for full legal notices.";

    revision "2019-09-09" {
         description "Initial revision.";
         reference "RFC XXXX: A Yang Data Model for L1 Connectivity
                   Service Model (L1CSM)";
    // Note: The RFC Editor will replace XXXX with the number
    // assigned to the RFC once this draft becomes an RFC.
    }

          grouping protocol-coding-optical-interface {
       description
        "describes <p,c,o> where p:protocol type; c:coding
         function; o:optical interface function";
        reference "MEF 63";
        leaf protocol {
          type identityref {
            base "layer1-types:client-signal";
          }
          description
            "List of physical layer L1VC client protocol";

        }
        leaf coding {
           type identityref {
             base "layer1-types:coding-func";
           }



Lee, et al.              Expires March 12, 2020                 [Page 9]

Internet-Draft     A YANG Data Model for Layer 1 Types    September 2019


           description "coding function";
        }

         leaf optical-interface {
           type identityref {
             base "layer1-types:optical-interface-func";
           }
           description "optical-interface-function";
        }

       }

    grouping subscriber-l1vc-sls-service-attribute {
       description
        "The value of the Subscriber L1VC SLS (Service Level
          Specification) Service Attribute";
        reference "MEF 63";

        leaf start-time {
          type yang:date-and-time;
          description "a time that represent the date and time
                       for the start of the SLS";
        }

        leaf time-interval {
          type int32;
          units seconds;
          description "a time interval (e.g., 2,419,200 seconds
                       which is 28 days) that is used in
                       conjunction wuth time-start to specify a
                       contiguous sequence of time intervals T for
                       determining when performance objectives are
                       met.";
        }

        leaf-list performance-metric {
          type identityref {
            base "layer1-types:service-performance-metric";
          }
          description "list of service performance metric.";
        }

    }

    grouping subscriber-l1vc-endpoint-attributes {
       description
        "subscriber layer 1 connection endpoint attributes";
        reference "MEF 63";



Lee, et al.              Expires March 12, 2020                [Page 10]

Internet-Draft     A YANG Data Model for Layer 1 Types    September 2019


        container endpoint-1 {
          description "One end of UNI id's - string and id";
          leaf id {
            type string;
            mandatory true;
            description "subscriber end point ID of one end";
          }

          leaf uni {
            type leafref {
              path "/l1-connectivity/access/unis/uni/id";
            }
             mandatory true;
            description "this is one end of subscriber L1VC end point
             ID value = UNI-1";
          }
        }
        container endpoint-2 {
          description "One end of UNI id's - string and id";
          leaf id {
            type string;
             mandatory true;
            description "subscriber end point ID of the other end";
          }

          leaf uni {
            type leafref {
              path "/l1-connectivity/access/unis/uni/id";
            }
             mandatory true;
            description
               "this is one other end of subscriber L1VC end point
                ID value = UNI-2";
          }
        }
    }

    container l1-connectivity {
      description
        "serves as a top-level container for a list of layer 1
         connection services (l1cs)";

        container access {
          description "UNI configurations for access networks";

          container unis {
            description "the list of UNI's to be configured";




Lee, et al.              Expires March 12, 2020                [Page 11]

Internet-Draft     A YANG Data Model for Layer 1 Types    September 2019


            list uni {
              key "id";
              description "UNI identifier";
                  leaf id {
                    type string;
                     description "the UNI id of UNI Service Attributes";
                  }

                 uses protocol-coding-optical-interface;
            }
          }
        }

         container services {
           description "L1VC services";
             list service {
               key "service-id";
               description
                 "an unique identifier of a subscriber L1VC service";

                 leaf service-id {
                   type string;
                       mandatory true;
                   description "a unique service identifier for
                      subscriber L1VC.";
                 }

                 uses subscriber-l1vc-endpoint-attributes;
                 uses subscriber-l1vc-sls-service-attribute;

             }//end of service list
         } //end of service container
    }//service top container
  }


  <CODE ENDS>



5.  JSON Example

   This section provides a JSON example of the YANG module described in
   Section 4.  This example configures one L1VC service with two UNIs
   that describe the UNI endpoints.  The service is configured with the
   starting time to be 06:06:09 on 2018-09-13 for the service life time
   of 2419200 seconds (which is corresponds to 28 days).  In addition,




Lee, et al.              Expires March 12, 2020                [Page 12]

Internet-Draft     A YANG Data Model for Layer 1 Types    September 2019


   the service is configured to collect one performance metric, One-way-
   Delay.


   {
     "l1-connectivity": {
       "access": {
         "unis": {
           "uni": [
             {
               "id": "MTL-HQ-Node3-Slot2-Port1",
               "protocol": "ETH-10GigE_LAN ",
               "coding": "ETH-10GR-PCS-49 ",
               "optical_interface": "LR-PMD-clause-52 "
             },
             {
               "id": "MTL-STL-Node5-Slot4-Port3",
               "protocol": "ETH-10GigE_LAN ",
               "coding": "ETH-10GR-PCS-49 ",
               "optical_interface": "ER-PMD-clause-52 "
             }
           ]
         },
       },
       "services": {
         "service": [
           {
             "service-id": "Sub-L1VC-1867-LT-MEGAMART",
             "endpoint-1":
               {
                 "id": "MTL-HQ_1867-MEGAMART",
                 "uni": "MTL-HQ-Node3-Slot2-Port1"
               },
             "endpoint-2":
               {
                 "id": "MTL-STL_1867-MEGAMART",
                 "uni": "MTL-STL-Node5-Slot4-Port3"
               },
             "start-time": "2018-09-13T06:06:09Z",
             "time-interval": 2419200,
             "performance-metric": "One-way-Delay "
           }
         ]
       },
   }






Lee, et al.              Expires March 12, 2020                [Page 13]

Internet-Draft     A YANG Data Model for Layer 1 Types    September 2019


6.  Security Considerations

   The YANG module specified in this document defines a schema for data
   that is designed to be accessed via network management protocols such
   as NETCONF [RFC6241] or RESTCONF [RFC8040].  The lowest NETCONF layer
   is the secure transport layer, and the mandatory-to-implement secure
   transport is Secure Shell (SSH) [RFC6242].  The lowest RESTCONF layer
   is HTTPS, and the mandatory-to-implement secure transport is TLS
   [RFC8446].

   The NETCONF access control model [RFC8341] provides the means to
   restrict access for particular NETCONF or RESTCONF users to a
   preconfigured subset of all available NETCONF or RESTCONF protocol
   operations and content.

   A number of configuration data nodes defined in this document are
   writable/deletable (i.e., "config true") These data nodes may be
   considered sensitive or vulnerable in some network environments.

   These are the subtrees and data nodes and their sensitivity/
   vulnerability:

   unis:

   - id

   Service:

   - service-id

   - endpoint-1

   - endpoint-2

   - start-time

   - time-interval

   - performance-metric

   The security considerations spelled out in the YANG 1.1 specification
   [RFC7950] apply for this document as well.

7.  IANA Considerations

   It is proposed that IANA should assign new URIs from the "IETF XML
   Registry" [RFC3688] as follows:




Lee, et al.              Expires March 12, 2020                [Page 14]

Internet-Draft     A YANG Data Model for Layer 1 Types    September 2019


         URI: urn:ietf:params:xml:ns:yang:ietf-l1csm
         Registrant Contact: The IESG
         XML: N/A; the requested URI is an XML namespace.


   This document registers following YANG modules in the YANG Module
   Names registry [RFC7950].


      name:         ietf-l1csm
      namespace:    urn:ietf:params:xml:ns:yang:ietf-l1csm
      prefix:       l1csm
      reference:    RFC XXXX


8.  Acknowledgements

   The authors would like to thank Tom Petch for his helpful comments
   and valuable contributions and Robert Wilton for his review that
   improved the model significantly.

9.  Contributors

   Italo Busi
   Huawei Technologies
   Email: Italo.Busi@huawei.com

   Giuseppe Fioccola
   Huawei Technologies
   Email: giuseppe.fioccola@huawei.com

10.  References

10.1.  Normative References

   [MEF63]    Metro Ethernet Forum, "Subscriber Layer1 Service
              Attributes Technical Specification", MEF 63, August 2018.

   [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
              DOI 10.17487/RFC3688, January 2004,
              <https://www.rfc-editor.org/info/rfc3688>.

   [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>.





Lee, et al.              Expires March 12, 2020                [Page 15]

Internet-Draft     A YANG Data Model for Layer 1 Types    September 2019


   [RFC6242]  Wasserman, M., "Using the NETCONF Protocol over Secure
              Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
              <https://www.rfc-editor.org/info/rfc6242>.

   [RFC6991]  Schoenwaelder, J., Ed., "Common YANG Data Types",
              RFC 6991, DOI 10.17487/RFC6991, July 2013,
              <https://www.rfc-editor.org/info/rfc6991>.

   [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>.

   [RFC8340]  Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
              BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
              <https://www.rfc-editor.org/info/rfc8340>.

   [RFC8341]  Bierman, A. and M. Bjorklund, "Network Configuration
              Access Control Model", STD 91, RFC 8341,
              DOI 10.17487/RFC8341, March 2018,
              <https://www.rfc-editor.org/info/rfc8341>.

   [RFC8342]  Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
              and R. Wilton, "Network Management Datastore Architecture
              (NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018,
              <https://www.rfc-editor.org/info/rfc8342>.

   [RFC8446]  Rescorla, E., "The Transport Layer Security (TLS) Protocol
              Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
              <https://www.rfc-editor.org/info/rfc8446>.

10.2.  Informative References

   [I-D.ietf-ccamp-layer1-types]
              Zheng, H. and I. Busi, "A YANG Data Model for Layer 1
              Types", draft-ietf-ccamp-layer1-types-01 (work in
              progress), July 2019.

   [RFC4847]  Takeda, T., Ed., "Framework and Requirements for Layer 1
              Virtual Private Networks", RFC 4847, DOI 10.17487/RFC4847,
              April 2007, <https://www.rfc-editor.org/info/rfc4847>.







Lee, et al.              Expires March 12, 2020                [Page 16]

Internet-Draft     A YANG Data Model for Layer 1 Types    September 2019


   [RFC5253]  Takeda, T., Ed., "Applicability Statement for Layer 1
              Virtual Private Network (L1VPN) Basic Mode", RFC 5253,
              DOI 10.17487/RFC5253, July 2008,
              <https://www.rfc-editor.org/info/rfc5253>.

   [RFC8199]  Bogdanovic, D., Claise, B., and C. Moberg, "YANG Module
              Classification", RFC 8199, DOI 10.17487/RFC8199, July
              2017, <https://www.rfc-editor.org/info/rfc8199>.

   [RFC8309]  Wu, Q., Liu, W., and A. Farrel, "Service Models
              Explained", RFC 8309, DOI 10.17487/RFC8309, January 2018,
              <https://www.rfc-editor.org/info/rfc8309>.

Authors' Addresses

   Young Lee
   SKKU
   Sung Kyun Kwan University
   Seoul
   South Korea

   Email: younglee.tx@gmail.com


   KwangKoog Lee
   Korea Telecom
   South Korea

   Email: kwangkoog.lee@kt.com


   Haomian Zheng
   Huawei Technologies
   H1-1-A043S Huawei Industrial Base, Songshanhu
   Dongguan, Guangdong  523808
   China

   Email: zhenghaomian@huawei.com


   Dhruv Dhody
   Huawei Technologies
   India

   Email: dhruv.ietf@gmail.com






Lee, et al.              Expires March 12, 2020                [Page 17]

Internet-Draft     A YANG Data Model for Layer 1 Types    September 2019


   Oscar Gonzalez de Dios
   Telefonica

   Email: oscar.gonzalezdedios@telefonica.com


   Daniele Ceccarelli
   Ericsson

   Email: daniele.ceccarelli@ericsson.com









































Lee, et al.              Expires March 12, 2020                [Page 18]