Internet-Draft A YANG Data Model for Layer 0 Types October 2020
Zheng, et al. Expires 19 April 2021 [Page]
Workgroup:
CCAMP Working Group
Internet-Draft:
draft-ietf-ccamp-layer0-types-08
Published:
Intended Status:
Standards Track
Expires:
Authors:
H. Zheng
Huawei Technologies
Y. Lee
Samsung
A. Guo
Futurewei
V. Lopez
Telefonica
D. King
University of Lancaster

A YANG Data Model for Layer 0 Types

Abstract

This document defines a collection of common data types and groupings in the YANG data modeling language. These derived common types and groupings are intended to be imported by modules that model Layer 0 optical Traffic Engineering (TE) configuration and state capabilities such as Wavelength Switched Optical Networks (WSONs) and Flexi-grid Dense Wavelength Division Multiplexing (DWDM) Networks.

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 19 April 2021.

▲

Table of Contents

1. Introduction

YANG [RFC7950] is a data modeling language used to model configuration data, state data, Remote Procedure Calls, and notifications for network management protocols such as NETCONF [RFC6241]. The YANG language supports a small set of built-in data types and provides mechanisms to derive other types from the built-in types.

This document introduces a collection of common data types derived from the built-in YANG data types. The derived types and groupings are designed to be the common types applicable for modeling Traffic Engineering (TE) features as well as non-TE features (e.g., physical network configuration aspect) for Layer 0 optical networks in model(s) defined outside of this document. The applicability of Layer 0 types specified in this document include Wavelength Switched Optical Networks (WSONs) [RFC6163] and [ITU-Tg6982], and Flexi-grid Dense Wavelength Division Multiplexing (DWDM) Networks [RFC7698] and [ITU-Tg6941] .

1.1. Terminology and Notations

Refer to [RFC7446] and [RFC7581] for the key terms used in this document, and the terminology for describing YANG data models can be found in [RFC7950].

The YANG data model in this document conforms to the Network Management Datastore Architecture defined in [RFC8342].

1.2. Prefix 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.


    +-------------+---------------------------+----------------------+
    | Prefix      | YANG module               | Reference            |
    +-------------+---------------------------+----------------------+
    | l0-types    | ietf-layer0-types         | [RFCXXXX]            |
    +-------------+---------------------------+----------------------+

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

YANG module ietf-layer0-types (defined in Section 3) references [RFC6163], [RFC7205], and [RFC7698].

2. Layer 0 Types Module Contents

This document defines YANG module for common Layer 0 types, ietf-layer0-types. This module is used for WSON and Flexi-grid DWDM networks. The ietf-layer0-types module contains the following YANG reusable types and groupings:

l0-grid-type:

A base YANG identity for the grid type as defined in [RFC6163] and [RFC7698].

dwdm-ch-spc-type:

A base YANG identity for the DWDM channel spacing type as defined in [RFC6205].

cwdm-ch-spc-type:

A base YANG identity for the CWDM channel spacing type as defined in [RFC6205].

wson-label-start-end:

A YANG grouping that defines the label-start or label-end to specify WSON label range as defined in [RFC6205].

wson-label-hop:

A YANG grouping that defines the label hop for WSON as defined in [RFC6205].

l0-label-range-info:

A YANG grouping that defines the layer 0 label range information applicable for both WSON per priority level as defined in [RFC6205]. This grouping is used in the flexi-grid DWDM by adding more flexi-grid-specific parameters.

wson-label-step:

A YANG grouping that defines label steps for WSON as defined in [RFC8776].

flexi-grid-label-start-end:

A YANG grouping that defines the label-start or label-end to specify flexi-grid label range as defined in [RFC7698].

flexi-grid-label-hop:

A YANG grouping that defines the label hop for both single channel and multiple carriers in flexi-grid DWDM, as defined in [RFC7698].

flexi-grid-label-range-info:

A YANG grouping that defines flexi-grid label range information and per priority level as defined in [RFC7698] and [RFC8363].

flexi-grid-label-step:

A YANG grouping that defines flexi-grid label steps as defined in [RFC8776].

3. YANG Code for Layer 0 Types 

<CODE BEGINS>file "ietf-layer0-types@2020-10-16.yang"
module ietf-layer0-types {
  yang-version 1.1;
  namespace "urn:ietf:params:xml:ns:yang:ietf-layer0-types";

  prefix "l0-types";

  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: Young Lee
       <mailto:younglee.tx@gmail.com>

     Editor: Aihua Guo
       <mailto:aihuaguo.ietf@gmail.com>

     Editor: Victor Lopez
       <mailto:victor.lopezalvarez@telefonica.com>

     Editor: Daniel King
       <mailto:d.king@lancaster.ac.uk>";

  description
    "This module defines Optical Layer 0 types. This module
     provides groupings that can be applicable to Layer 0
     Fixed Optical Networks (e.g., CWDM (Coarse Wavelength
     Division Multiplexing) and DWDM (Dense Wavelength Division
     Multiplexing)) and Flexi-grid Optical Networks.

     Copyright (c) 2020 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 "2020-10-16" {
    description
      "Initial Version";
    reference
      "RFC XXXX: A YANG Data Model for Layer 0 Types";
  }

  typedef dwdm-n {
    type int16;
    description
      "The given value 'N' is used to determine the nominal
       central frequency.

       The nominal central frequency, 'f' is defined by:
         f = 193100.000 GHz + N x channel-spacing (measured in GHz)
       where 193100.000 GHz (193.100000 THz) is the ITU-T 'anchor
         frequency' for transmission over the C band; and
       where 'channel-spacing' is defined by the dwdm-ch-spc-type.";
    reference
      "RFC6205: Generalized Labels for
       Lambda-Switch-Capable (LSC) Label Switching Routers,
       ITU-T G.694.1 (02/2012): Spectral grids for WDM applications:
       DWDM frequency grid";
  }

  typedef cwdm-n {
    type int16;
    description
      "The given value 'N' is used to determine the nominal
       central wavelength.

       The nominal central wavelength is defined by:
         Wavelength = 1471 nm + N x channel-spacing (measured in nm)
       where 1471 nm is the ITU-T 'anchor wavelength' for
         transmission over the C band; and
       where 'channel-spacing' is defined by the cwdm-ch-spc-type.";
    reference
      "RFC6205: Generalized Labels for
       Lambda-Switch-Capable (LSC) Label Switching Routers,
       ITU-T G.694.2 (12/2003): Spectral grids for WDM applications:
       CWDM wavelength grid";
  }

  typedef flexi-n {
    type int16;
    description
      "The given value 'N' is used to determine the nominal
       central frequency.

       The nominal central frequency, 'f' is defined by,
         f = 193100.000 GHz + N x channel-spacing (measured in GHz),
       where 193100.000 GHz (193.100000 THz) is the ITU-T 'anchor
         frequency' for transmission over the C band; and
       where 'channel-spacing' is defined by the flexi-ch-spc-type.

       Note that the term 'channel-spacing' can be alternated by the
       term 'nominal central frequency granularity' defined in
       clause 7 of ITU-T G.694.1.";
    reference
      "RFC7698: Framework and Requirements for GMPLS-Based Control
       of Flexi-Grid Dense Wavelength Division Multiplexing (DWDM)
       Networks.
       ITU-T G.694.1 (02/2012): Spectral grids for WDM applications:
       DWDM frequency grid";
  }

  typedef flexi-m {
    type uint16;
    description
      "The given value 'M' is used to determine the slot width.

       A slot width is defined by:
         slot width = M x SWG (measured in GHz),
       where SWG is defined by the flexi-slot-width-granularity.";
    reference
      "RFC7698: Framework and Requirements for GMPLS-Based Control
       of Flexi-Grid Dense Wavelength Division Multiplexing (DWDM)
       Networks.
       ITU-T G.694.1 (02/2012): Spectral grids for WDM applications:
       DWDM frequency grid";
  }

  identity l0-grid-type {
    description
      "Layer 0 grid type";
    reference
      "RFC6163:Framework for GMPLS and Path Computation Element
       (PCE) Control of Wavelength Switched Optical Networks (WSONs),
       ITU-T G.694.1 (02/2012): Spectral grids for WDM applications:
       DWDM frequency grid,
       ITU-T G.694.2 (12/2003): Spectral grids for WDM applications:
       CWDM wavelength grid";
  }

  identity flexi-grid-dwdm {
    base l0-grid-type;
    description
      "Flexi-grid";
    reference
      "RFC7698: Framework and Requirements for GMPLS-Based Control
       of Flexi-Grid Dense Wavelength Division Multiplexing (DWDM)
       Networks,
       ITU-T G.694.1 (02/2012): Spectral grids for WDM applications:
       DWDM frequency grid";
  }

  identity wson-grid-dwdm {
    base l0-grid-type;
    description
      "DWDM grid";
    reference
      "RFC6163:Framework for GMPLS and Path Computation Element
       (PCE) Control of Wavelength Switched Optical Networks (WSONs),
       ITU-T G.694.1 (02/2012): Spectral grids for WDM applications:
       DWDM frequency grid";
  }

  identity wson-grid-cwdm {
    base l0-grid-type;
    description
      "CWDM grid";
    reference
      "RFC6205: Generalized Labels for
       Lambda-Switch-Capable (LSC) Label Switching Routers,
       ITU-T G.694.2 (12/2003): Spectral grids for WDM applications:
       CWDM wavelength grid";
  }

  identity dwdm-ch-spc-type {
    description
      "DWDM channel spacing type";
    reference
      "RFC6205: Generalized Labels for
       Lambda-Switch-Capable (LSC) Label Switching Routers,
       ITU-T G.694.1 (02/2012): Spectral grids for WDM applications:
       DWDM frequency grid";
  }

  identity dwdm-100ghz {
    base dwdm-ch-spc-type;
    description
      "100GHz channel spacing";
  }

  identity dwdm-50ghz {
    base dwdm-ch-spc-type;
    description
      "50GHz channel spacing";
  }

  identity dwdm-25ghz {
    base dwdm-ch-spc-type;
    description
      "25GHz channel spacing";
  }

  identity dwdm-12p5ghz {
    base dwdm-ch-spc-type;
    description
      "12.5GHz channel spacing";
  }

  identity flexi-ch-spc-type {
    description
      "Flexi-grid channel spacing type";
    reference
      "RFC7698: Framework and Requirements for GMPLS-Based Control
       of Flexi-Grid Dense Wavelength Division Multiplexing (DWDM)
       Networks
       ITU-T G.694.1 (02/2012): Spectral grids for WDM applications:
       DWDM frequency grid";
  }

  identity flexi-ch-spc-6p25ghz {
    base flexi-ch-spc-type;
    description
      "6.25GHz channel spacing";
  }

  identity flexi-slot-width-granularity {
    description
      "Flexi-grid slot width granularity";
  }

  identity flexi-swg-12p5ghz {
    base flexi-slot-width-granularity;
    description
      "12.5GHz slot width granularity";
  }

  identity cwdm-ch-spc-type {
    description
      "CWDM channel spacing type";
    reference
      "RFC6205: Generalized Labels for
       Lambda-Switch-Capable (LSC) Label Switching Routers,
       ITU-T G.694.2 (12/2003): Spectral grids for WDM applications:
       CWDM wavelength grid";
  }

  identity cwdm-20nm {
    base cwdm-ch-spc-type;
    description
      "20nm channel spacing";
  }

  /* Groupings. */

  grouping wson-label-start-end {
    description
      "The WSON label-start or label-end used to
       specify WSON label range.";
    choice grid-type {
      description
        "Label for DWDM or CWDM grid";
      case dwdm {
        leaf dwdm-n {
          when 'derived-from-or-self(../../../grid-type,
          "wson-grid-dwdm")'
          {
            description
              "Valid only when grid type is DWDM.";
          }
          type l0-types:dwdm-n;
          description
           "The central frequency of DWDM. ";
          reference
            "RFC6205: Generalized Labels for
             Lambda-Switch-Capable (LSC) Label Switching Routers";
        }
      }
      case cwdm {
        leaf cwdm-n {
          when 'derived-from-or-self(../../../grid-type,
          "wson-grid-cwdm")'
          {
            description
              "Valid only when grid type is CWDM.";
          }
          type l0-types:cwdm-n;
          description
            "Channel wavelength computing input. ";
          reference
            "RFC6205: Generalized Labels for
             Lambda-Switch-Capable (LSC) Label Switching Routers";
        }
      }
    }
    reference
      "RFC6205: Generalized Labels for
       Lambda-Switch-Capable (LSC) Label Switching Routers";
  }

  grouping wson-label-hop {
    description
      "Generic label hop information for WSON";
    choice grid-type {
      description
        "Label for DWDM or CWDM grid";
      case dwdm {
        choice single-or-super-channel {
          description "single or super channel";
          case single {
            leaf dwdm-n {
              type l0-types:dwdm-n;
              description
                "The given value 'N' is used to determine the
                 nominal central frequency.";
            }
          }
          case super {
            leaf-list subcarrier-dwdm-n {
              type l0-types:dwdm-n;
              description
                "The given values 'N' are used to determine the
                 nominal central frequency for each subcarrier
                 channels.";
              reference
                "ITU-T Recommendation G.694.1: Spectral grids for
                 WDM applications: DWDM frequency grid";
            }
          }
        }
      }
      case cwdm {
        leaf cwdm-n {
          type l0-types:cwdm-n;
          description
            "The given value 'N' is used to determine the nominal
             central wavelength.";
          reference
            "RFC6205: Generalized Labels for
             Lambda-Switch-Capable (LSC) Label Switching Routers";
        }
      }
    }
    reference
      "RFC6205: Generalized Labels for
      Lambda-Switch-Capable (LSC) Label Switching Routers";
  }

  grouping l0-label-range-info {
    description
      "Information for layer 0 label range.";
    leaf grid-type {
      type identityref {
        base l0-grid-type;
      }
      description "Grid type";
    }
    leaf priority {
      type uint8;
      description
        "Priority in Interface Switching Capability
         Descriptor (ISCD).";
      reference
        "RFC4203: OSPF Extensions in Support of Generalized
         Multi-Protocol Label Switching (GMPLS).";
    }
    reference
      "RFC6205: Generalized Labels for
       Lambda-Switch-Capable (LSC) Label Switching Routers";
  }

  grouping wson-label-step {
    description "Label step information for WSON";
    choice l0-grid-type {
      description
        "Grid type: DWDM, CWDM, etc.";
      case dwdm {
        leaf wson-dwdm-channel-spacing {
          when 'derived-from-or-self(../../grid-type,
          "wson-grid-dwdm")'
          {
            description
              "Valid only when grid type is DWDM.";
          }
          type identityref {
            base dwdm-ch-spc-type;
          }
          description
            "Label-step is the channel-spacing (GHz), e.g.,
             100.000, 50.000, 25.000, or 12.500 GHz for DWDM";
          reference
            "RFC6205: Generalized Labels for
             Lambda-Switch-Capable (LSC) Label Switching Routers";
        }
      }
      case cwdm {
        leaf wson-cwdm-channel-spacing {
          when 'derived-from-or-self(../../grid-type,
          "wson-grid-cwdm")'
          {
            description
              "Valid only when grid type is CWDM.";
          }
          type identityref {
            base cwdm-ch-spc-type;
          }
          description
            "Label-step is the channel-spacing (nm), i.e., 20 nm
             for CWDM, which is the only value defined for CWDM";
          reference
            "RFC6205: Generalized Labels for
             Lambda-Switch-Capable (LSC) Label Switching Routers";
        }
      }
    }
    reference
      "RFC6205: Generalized Labels for
       Lambda-Switch-Capable (LSC) Label Switching Routers
       ITU-T G.694.2 (12/2003): Spectral grids for WDM applications:
       CWDM wavelength grid";
  }

  grouping flexi-grid-label-start-end {
    description
      "The Flexi-grid label-start or label-end used to
       specify Flexi-grid label range.";
    leaf flexi-n {
      type l0-types:flexi-n;
      description
        "The given value 'N' is used to determine the nominal
         central frequency.";
    }
    reference
      "RFC7698: Framework and Requirements for GMPLS-Based Control
       of Flexi-Grid Dense Wavelength Division Multiplexing (DWDM)
       Networks";
  }

  grouping flexi-grid-frequency-slot {
    description "Flexi-grid frequency slot grouping.";
    uses flexi-grid-label-start-end;
    leaf flexi-m {
      type l0-types:flexi-m;
      description
        "The given value 'M' is used to determine the slot width.";
    }
    reference
      "RFC7698: Framework and Requirements for GMPLS-Based Control
       of Flexi-Grid Dense Wavelength Division Multiplexing (DWDM)
       Networks";
  }

  grouping flexi-grid-label-hop {
    description
      "Generic label hop information for Flexi-grid";

    choice single-or-super-channel {
      description "single or super channel";
      case single {
        uses flexi-grid-frequency-slot;
      }
      case super {
        list subcarrier-flexi-n {
          key flexi-n;
          uses flexi-grid-frequency-slot;
          description
            "List of subcarrier channels for flexi-grid
             super channel.";
        }
      }
    }
    reference
      "RFC7698: Framework and Requirements for GMPLS-Based Control
       of Flexi-Grid Dense Wavelength Division Multiplexing (DWDM)
       Networks";
  }

  grouping flexi-grid-label-range-info {
    description
      "Info of Flexi-grid-specific label range";
    uses l0-label-range-info;
    container flexi-grid {
      description "flexi-grid definition";
      leaf slot-width-granularity {
        type identityref {
          base flexi-slot-width-granularity;
        }
        default flexi-swg-12p5ghz;
        description
          "Minimum space between slot widths. Default is
           12.500 GHz";
        reference
          "RFC7698: Framework and Requirements for GMPLS-Based
           Control of Flexi-Grid Dense Wavelength Division
           Multiplexing (DWDM) Networks";
      }
      leaf min-slot-width-factor {
        type uint16 {
          range "1..max";
        }
        default 1;
        description
          "Slot width range: two multipliers of the slot width ,
           granularity, each indicating the minimal and maximal slot
           width supported by a port, respectively.

           Minimum slot width is calculated by:
             Minimum slot width (GHz) =
               min-slot-width-factor * slot-width-granularity.
           Minimum slot width should be smaller than or equal to
           Maximum slot width. ";
        reference
          "RFC8363: GMPLS OSPF-TE Extensions in Support of Flexi-Grid
           Dense Wavelength Division Multiplexing (DWDM) Networks";
      }

      leaf max-slot-width-factor {
        type uint16 {
          range "1..max";
        }
        description
          "Slot width range: two multipliers of the slot width ,
           granularity, each indicating the minimal and maximal slot
           width supported by a port, respectively.

           Maximum slot width is calculated by:
             Maximum slot width (GHz) =
               max-slot-width-factor * slot-width-granularity
           Maximum slot width should be bigger than or equal to
           Minimum slot width. ";
        reference
          "RFC8363: GMPLS OSPF-TE Extensions in Support of Flexi-Grid
           Dense Wavelength Division Multiplexing (DWDM) Networks";
      }
    }
  }

  grouping flexi-grid-label-step {
    description "Label step information for flexi-grid";
    leaf flexi-grid-channel-spacing {
      type identityref {
        base flexi-ch-spc-type;
      }
      default flexi-ch-spc-6p25ghz;
      description
        "Label-step is the nominal central frequency
         granularity (GHz), e.g., 6.25 GHz";
      reference
         "RFC7699: Generalized Labels for the Flexi-Grid in
          Lambda Switch Capable (LSC) Label Switching Routers";
    }
    leaf flexi-n-step {
      type uint8;
      description
        "This attribute defines the multiplier for the supported
         values of 'N'.

         For example, given a grid with a nominal central frequency
         granularity of 6.25 GHz, the granularity of the supported
         values of the nominal central frequency could be 12.5 GHz.
         In this case, the values of flexi-n should be even and this
         constraints is reported by setting the flexi-n-step to 2.

         This attribute is also known as central frequency
         granularity in RFC8363.";
      reference
        "RFC8363: GMPLS OSPF-TE Extensions in Support of Flexi-Grid
         Dense Wavelength Division Multiplexing (DWDM) Networks";
    }
  }
}


<CODE ENDS>

4. 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 users to a preconfigured subset of all available NETCONF protocol operations and content. The NETCONF Protocol over Secure Shell (SSH) [RFC6242] describes a method for invoking and running NETCONF within a Secure Shell (SSH) session as an SSH subsystem. 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.

The objects in this YANG module are common data types and groupings. No object in this module can be read or written to. These definitions can be imported and used by other layer 0 specific modules. It is critical consider how imported definitions will be utilized and accessible via RPC operations, as the resultant schema will have data nodes that can be writable, or readable, and will have a significant effect on the network operations if used incorrectly or maliciously. All of this consideration belongs in the document that defines the modules that import from this YANG module. Therefore, it is important to manage access to resultant data nodes that are considered sensitive or vulnerable in some network environments.

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

5. IANA Considerations

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


      URI: urn:ietf:params:xml:ns:yang:ietf-layer0-types
      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-layer0-types
   namespace:    urn:ietf:params:xml:ns:yang:ietf-layer0-types
   prefix:       l0-types
   reference:    RFC XXXX(TBD)

6. Acknowledgements

The authors and the working group give their sincere thanks for Robert Wilton for the YANG doctor review, and Tom Petch for his comments during the model and document development.

7. Contributors

Dhruv Dhody Huawei Email: dhruv.ietf@gmail.com

Bin Yeong Yoon ETRI Email: byyun@etri.re.kr

Ricard Vilalta CTTC Email: ricard.vilalta@cttc.es

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

8. References

8.1. Normative References

[RFC4203]
Kompella, K., Ed. and Y. Rekhter, Ed., "OSPF Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)", RFC 4203, DOI 10.17487/RFC4203, , <https://www.rfc-editor.org/info/rfc4203>.
[RFC6241]
Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., and A. Bierman, Ed., "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, , <https://www.rfc-editor.org/info/rfc6241>.
[RFC6242]
Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, , <https://www.rfc-editor.org/info/rfc6242>.
[RFC7699]
Farrel, A., King, D., Li, Y., and F. Zhang, "Generalized Labels for the Flexi-Grid in Lambda Switch Capable (LSC) Label Switching Routers", RFC 7699, DOI 10.17487/RFC7699, , <https://www.rfc-editor.org/info/rfc7699>.
[RFC7950]
Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, , <https://www.rfc-editor.org/info/rfc7950>.
[RFC8040]
Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, , <https://www.rfc-editor.org/info/rfc8040>.
[RFC8341]
Bierman, A. and M. Bjorklund, "Network Configuration Access Control Model", STD 91, RFC 8341, DOI 10.17487/RFC8341, , <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, , <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, , <https://www.rfc-editor.org/info/rfc8446>.

8.2. Informative References

[ITU-Tg6941]
International Telecommunication Union, "Spectral grids for WDM applications: DWDM frequency grid", ITU-T G.694.1, .
[ITU-Tg6942]
International Telecommunication Union, "Spectral grids for WDM applications: CWDM wavelength grid", ITU-T G.694.2, .
[ITU-Tg6982]
International Telecommunication Union, "Amplified multichannel dense wavelength division multiplexing applications with single channel optical interfaces", ITU-T G.698.2, .
[ITU-Tg709]
International Telecommunication Union, "Interfaces for the optical transport network", ITU-T G.709, .
[RFC3688]
Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, , <https://www.rfc-editor.org/info/rfc3688>.
[RFC6163]
Lee, Y., Ed., Bernstein, G., Ed., and W. Imajuku, "Framework for GMPLS and Path Computation Element (PCE) Control of Wavelength Switched Optical Networks (WSONs)", RFC 6163, DOI 10.17487/RFC6163, , <https://www.rfc-editor.org/info/rfc6163>.
[RFC6205]
Otani, T., Ed. and D. Li, Ed., "Generalized Labels for Lambda-Switch-Capable (LSC) Label Switching Routers", RFC 6205, DOI 10.17487/RFC6205, , <https://www.rfc-editor.org/info/rfc6205>.
[RFC7205]
Romanow, A., Botzko, S., Duckworth, M., and R. Even, Ed., "Use Cases for Telepresence Multistreams", RFC 7205, DOI 10.17487/RFC7205, , <https://www.rfc-editor.org/info/rfc7205>.
[RFC7446]
Lee, Y., Ed., Bernstein, G., Ed., Li, D., and W. Imajuku, "Routing and Wavelength Assignment Information Model for Wavelength Switched Optical Networks", RFC 7446, DOI 10.17487/RFC7446, , <https://www.rfc-editor.org/info/rfc7446>.
[RFC7581]
Bernstein, G., Ed., Lee, Y., Ed., Li, D., Imajuku, W., and J. Han, "Routing and Wavelength Assignment Information Encoding for Wavelength Switched Optical Networks", RFC 7581, DOI 10.17487/RFC7581, , <https://www.rfc-editor.org/info/rfc7581>.
[RFC7698]
Gonzalez de Dios, O., Ed., Casellas, R., Ed., Zhang, F., Fu, X., Ceccarelli, D., and I. Hussain, "Framework and Requirements for GMPLS-Based Control of Flexi-Grid Dense Wavelength Division Multiplexing (DWDM) Networks", RFC 7698, DOI 10.17487/RFC7698, , <https://www.rfc-editor.org/info/rfc7698>.
[RFC8363]
Zhang, X., Zheng, H., Casellas, R., Gonzalez de Dios, O., and D. Ceccarelli, "GMPLS OSPF-TE Extensions in Support of Flexi-Grid Dense Wavelength Division Multiplexing (DWDM) Networks", RFC 8363, DOI 10.17487/RFC8363, , <https://www.rfc-editor.org/info/rfc8363>.
[RFC8776]
Saad, T., Gandhi, R., Liu, X., Beeram, V., and I. Bryskin, "Common YANG Data Types for Traffic Engineering", RFC 8776, DOI 10.17487/RFC8776, , <https://www.rfc-editor.org/info/rfc8776>.

Authors' Addresses

Haomian Zheng
Huawei Technologies
H1, Huawei Xiliu Beipo Village, Songshan Lake
Dongguan
Guangdong, 523808
China
Young Lee
Samsung
South Korea
Aihua Guo
Futurewei
Victor Lopez
Telefonica
Daniel King
University of Lancaster