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: <https://datatracker.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.lopez@nokia.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) 2021 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
     (https://trustee.ietf.org/license-info).

     This version of this YANG module is part of RFC 9093; see
     the RFC itself for full legal notices.";

    revision "2021-08-13" {
      description "Initial version";
      reference
        "RFC 9093: 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 DWDM grid, 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 (10/2020): 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 conventional 'anchor wavelength' for
       transmission over the CWDM grid, and where 'channel spacing'
       is defined by the cwdm-ch-spc-type.";
      reference
        "RFC 6205: 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 DWDM grid, and where
       'channel spacing' is defined by the flexi-ch-spc-type.

       Note that the term 'channel spacing' can be substituted by the
       term 'nominal central frequency granularity' defined in
       clause 8 of ITU-T G.694.1.";
      reference
        "RFC 7698: Framework and Requirements for GMPLS-Based Control
        of Flexi-Grid Dense Wavelength Division Multiplexing (DWDM)
        Networks,
        ITU-T G.694.1 (10/2020): 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
        "RFC 7698: Framework and Requirements for GMPLS-Based Control
        of Flexi-Grid Dense Wavelength Division Multiplexing (DWDM)
        Networks.
        ITU-T G.694.1 (10/2020): Spectral grids for WDM applications:
        DWDM frequency grid";

    }

    identity l0-grid-type {
      description "Layer 0 grid type";
      reference
        "RFC 6163: Framework for GMPLS and Path Computation Element
        (PCE) Control of Wavelength Switched Optical Networks (WSONs),
        ITU-T G.694.1 (10/2020): 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
        "RFC 7698: Framework and Requirements for GMPLS-Based Control
        of Flexi-Grid Dense Wavelength Division Multiplexing (DWDM)
        Networks,
        ITU-T G.694.1 (10/2020): Spectral grids for WDM applications:
        DWDM frequency grid";

    }

    identity wson-grid-dwdm {
      base l0-grid-type;
      description "DWDM grid";
      reference
        "RFC 6163:Framework for GMPLS and Path Computation Element
        (PCE) Control of Wavelength Switched Optical Networks (WSONs),
        ITU-T G.694.1 (10/2020): Spectral grids for WDM applications:
        DWDM frequency grid";

    }

    identity wson-grid-cwdm {
      base l0-grid-type;
      description "CWDM grid";
      reference
        "RFC 6205: 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
        "RFC 6205: Generalized Labels for Lambda-Switch-Capable (LSC)
        Label Switching Routers,
        ITU-T G.694.1 (10/2020): Spectral grids for WDM applications:
        DWDM frequency grid";

    }

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

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

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

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

    identity flexi-ch-spc-type {
      description
        "Flexi-grid channel-spacing type";
      reference
        "RFC 7698: Framework and Requirements for GMPLS-Based Control
        of Flexi-Grid Dense Wavelength Division Multiplexing (DWDM)
        Networks,
        ITU-T G.694.1 (10/2020): Spectral grids for WDM applications:
        DWDM frequency grid";

    }

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

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

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

    identity cwdm-ch-spc-type {
      description
        "CWDM channel-spacing type";
      reference
        "RFC 6205: 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";
    }

    grouping wson-label-start-end {
      description
        "The WSON label-start or label-end used to specify WSON label
       range.";
      reference
        "RFC 6205: Generalized Labels for Lambda-Switch-Capable (LSC)
        Label Switching Routers";

      choice grid-type {
        description
          "Label for DWDM or CWDM grid";
        leaf dwdm-n {
          when
            "derived-from-or-self(../../../grid-type,
                \"wson-grid-dwdm\")" {
            description
              "Valid only when grid type is DWDM.";
          }
          type dwdm-n;
          description
            "The central frequency of DWDM.";
          reference
            "RFC 6205: Generalized Labels for Lambda-Switch-Capable
            (LSC) Label Switching Routers";

        }
        leaf cwdm-n {
          when
            "derived-from-or-self(../../../grid-type,
                \"wson-grid-cwdm\")" {
            description
              "Valid only when grid type is CWDM.";
          }
          type cwdm-n;
          description
            "Channel wavelength computing input.";
          reference
            "RFC 6205: Generalized Labels for Lambda-Switch-Capable
            (LSC) Label Switching Routers";

        }
      }  // choice grid-type
    }  // grouping wson-label-start-end

    grouping wson-label-hop {
      description
        "Generic label-hop information for WSON";
      reference
        "RFC 6205: Generalized Labels for Lambda-Switch-Capable (LSC)
        Label Switching Routers";

      choice grid-type {
        description
          "Label for DWDM or CWDM grid";
        choice single-or-super-channel {
          description
            "single or super channel";
          leaf dwdm-n {
            type dwdm-n;
            description
              "The given value 'N' is used to determine the
                 nominal central frequency.";
          }
          leaf-list subcarrier-dwdm-n {
            type dwdm-n;
            description
              "The given values 'N' are used to determine the
                 nominal central frequency for each subcarrier
                 channel.";
            reference
              "ITU-T Recommendation G.694.1: Spectral grids for
              WDM applications: DWDM frequency grid";

          }
        }  // choice single-or-super-channel
        leaf cwdm-n {
          type cwdm-n;
          description
            "The given value 'N' is used to determine the nominal
             central wavelength.";
          reference
            "RFC 6205: Generalized Labels for Lambda-Switch-Capable
            (LSC) Label Switching Routers";

        }
      }  // choice grid-type
    }  // grouping wson-label-hop

    grouping l0-label-range-info {
      description
        "Information about Layer 0 label range.";
      reference
        "RFC 6205: Generalized Labels for Lambda-Switch-Capable (LSC)
        Label Switching Routers";

      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
          "RFC 4203: OSPF Extensions in Support of Generalized
          Multi-Protocol Label Switching (GMPLS)";

      }
    }  // grouping l0-label-range-info

    grouping wson-label-step {
      description
        "Label step information for WSON";
      reference
        "RFC 6205: 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";

      choice l0-grid-type {
        description
          "Grid type: DWDM, CWDM, etc.";
        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
            "RFC 6205: Generalized Labels for Lambda-Switch-Capable
            (LSC) Label Switching Routers";

        }
        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
            "RFC 6205: Generalized Labels for Lambda-Switch-Capable
            (LSC) Label Switching Routers";

        }
      }  // choice l0-grid-type
    }  // grouping wson-label-step

    grouping flexi-grid-label-start-end {
      description
        "The flexi-grid label-start or label-end used to specify
       flexi-grid label range.";
      reference
        "RFC 7698: Framework and Requirements for GMPLS-Based Control
        of Flexi-Grid Dense Wavelength Division Multiplexing (DWDM)
        Networks";

      leaf flexi-n {
        type flexi-n;
        description
          "The given value 'N' is used to determine the nominal
         central frequency.";
      }
    }  // grouping flexi-grid-label-start-end

    grouping flexi-grid-frequency-slot {
      description
        "Flexi-grid frequency slot grouping.";
      reference
        "RFC 7698: Framework and Requirements for GMPLS-Based Control
        of Flexi-Grid Dense Wavelength Division Multiplexing (DWDM)
        Networks";

      uses flexi-grid-label-start-end;

      leaf flexi-m {
        type flexi-m;
        description
          "The given value 'M' is used to determine the slot width.";
      }
    }  // grouping flexi-grid-frequency-slot

    grouping flexi-grid-label-hop {
      description
        "Generic label-hop information for flexi-grid";
      reference
        "RFC 7698: Framework and Requirements for GMPLS-Based Control
        of Flexi-Grid Dense Wavelength Division Multiplexing (DWDM)
        Networks";

      choice single-or-super-channel {
        description
          "single or super channel";
        case single {
          uses flexi-grid-frequency-slot;
        }  // case single
        list subcarrier-flexi-n {
          key "flexi-n";
          description
            "List of subcarrier channels for flexi-grid super
             channel.";
          uses flexi-grid-frequency-slot;
        }  // list subcarrier-flexi-n
      }  // choice single-or-super-channel
    }  // grouping flexi-grid-label-hop

    grouping flexi-grid-label-range-info {
      description
        "Flexi-grid-specific label range related information";
      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
            "RFC 7698: 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
            "A multiplier of the slot width granularity, indicating
           the minimum slot width supported by an optical port.

           Minimum slot width is calculated by:
             Minimum slot width (GHz) =
               min-slot-width-factor * slot-width-granularity.";
          reference
            "RFC 8363: 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";
          }
          must
            '. >= ../min-slot-width-factor' {
            error-message
              "Maximum slot width must be greater than or equal to
             minimum slot width.";
          }
          description
            "A multiplier of the slot width granularity, indicating
           the maximum slot width supported by an optical port.

           Maximum slot width is calculated by:
             Maximum slot width (GHz) =
               max-slot-width-factor * slot-width-granularity

           If specified, maximum slot width must be greater than or
           equal to minimum slot width.  If not specified, maximum
           slot width is equal to minimum slot width.";
          reference
            "RFC 8363: GMPLS OSPF-TE Extensions in Support of Flexi-
            Grid Dense Wavelength Division Multiplexing (DWDM)
            Networks";

        }
      }  // container flexi-grid
    }  // grouping flexi-grid-label-range-info

    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
          "RFC 7699: 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
         constraint is reported by setting the flexi-n-step to 2.

         This attribute is also known as central frequency
         granularity in RFC 8363.";
        reference
          "RFC 8363: GMPLS OSPF-TE Extensions in Support of Flexi-Grid
          Dense Wavelength Division Multiplexing (DWDM) Networks";

      }
    }  // grouping flexi-grid-label-step
  }  // module ietf-layer0-types