Skip to main content

A YANG Data Model for Optical Impairment-aware Topology
draft-ietf-ccamp-optical-impairment-topology-yang-07

The information below is for an old version of the document.
Document Type
This is an older version of an Internet-Draft whose latest revision state is "Active".
Authors Young Lee , Esther Le Rouzic , Victor Lopez , Gabriele Galimberti , Dieter Beller
Last updated 2021-07-08
Replaces draft-lee-ccamp-optical-impairment-topology-yang
RFC stream Internet Engineering Task Force (IETF)
Formats
Reviews
Additional resources Mailing list discussion
Stream WG state WG Document
Associated WG milestone
Dec 2022
Submit YANG model of WSON Impairment Topology YANG model to IESG for review;
Document shepherd (None)
IESG IESG state I-D Exists
Consensus boilerplate Unknown
Telechat date (None)
Responsible AD (None)
Send notices to (None)
draft-ietf-ccamp-optical-impairment-topology-yang-07
Lee, et al.              Expires January 9, 2022               [Page 35]
Internet-Draft    Opt. Impairment-Aware Topo YANG Model        July 2021

     grouping optical-channel-data {
     description
       "optical impairment data per channel/wavelength";
     leaf bit-rate {
       type decimal64 {
         fraction-digits 8;
           range "0..max";
       }
       units "Gbit/s";
       config false;
       description
         "Gross bit rate";
     }

     leaf BER {
       type decimal64 {
         fraction-digits 18;
         range "0..max";
       }
       config false;
       description
         "BER (Bit Error Rate)";
     }

     leaf ch-input-power {
       type decimal64 {
         fraction-digits 2;
       }
       units "dBm";
       config false;
       description
         "Per channel average input power level
         estimated at the receiver of the link";
     }

     leaf ch-pmd {
       type decimal64 {
           fraction-digits 8;
         range "0..max";
       }
       units "ps/(km)^0.5";
       config false;
       description
         "per channel Polarization Mode Dispersion";
     }

     leaf ch-cd {
       type decimal64 {

Lee, et al.              Expires January 9, 2022               [Page 36]
Internet-Draft    Opt. Impairment-Aware Topo YANG Model        July 2021

               fraction-digits 5;
       }
       units "ps/nm/km";
       config false;
             description
         "per channel Cromatic Dispersion";
     }

     leaf ch-osnr {
       type l0-types-ext:snr;
       config false;
       description
         "per channel Optical Signal-to-Noise Ratio
               (OSNR) estimated at the receiver";
      }

       leaf q-factor {
       type decimal64 {
         fraction-digits 5;
       }
       units "dB";
       config false;
         description
         "q-factor estimated at the receiver";
       }
     }

     /*
      * Groupings
      */

     grouping amplifier-params {
       description "describes parameters for an amplifier";
       container amplifier {
         description
           "amplifier type, operatonal parameters are described.";
         leaf type-variety {
           type string ;
           mandatory true ;
           description
             "String identifier of amplifier type referencing
             a specification in a separate equipment catalog";
         }
         container operational {
           description "amplifier operational parameters";
           list amplifier-element {
             description
               "The list of parallel amplifier elements within an

Lee, et al.              Expires January 9, 2022               [Page 37]
Internet-Draft    Opt. Impairment-Aware Topo YANG Model        July 2021

               amplifier used to amplify different frequency ranges.";
             leaf name {
               type string;
               description
                 "The name of the amplifier element as specified in
                 the vendor's specification associated with the
                 type-variety.";
             }
             container frequency-range {
               description
                 "The frequency range amplified by the amplifier
                 element.";
               uses l0-types-ext:frequency-range;
             }
             leaf actual-gain {
               type decimal64 {
                 fraction-digits 2;
               }
               units dB ;
               mandatory true ;
               description "..";
             }
             leaf tilt-target {
               type decimal64 {
                 fraction-digits 2;
               }
               mandatory true ;
               description "..";
             }
             leaf out-voa {
               type decimal64 {
                 fraction-digits 2;
               }
               units dB;
               mandatory true;
               description "..";
             }
             leaf in-voa {
               type decimal64 {
                 fraction-digits 2;
               }
               units dB;
               mandatory true;
               description "..";
             }
             uses power-param;
           }  // list amplifier-element
         }  // container operational

Lee, et al.              Expires January 9, 2022               [Page 38]
Internet-Draft    Opt. Impairment-Aware Topo YANG Model        July 2021

       }  // container amplifier
     }  // grouping amplifier-params

     grouping fiber-params {
       description
         "String identifier of fiber type referencing a
          specification in a separate equipment catalog";
       container fiber {
       description "fiber characteristics";
         leaf type-variety {
           type string ;
       mandatory true ;
           description "fiber type";
         }
         leaf length {
           type decimal64 {
             fraction-digits 2;
           }
           units km;
       mandatory true ;
       description "length of fiber";
         }
         leaf loss-coef {
           type decimal64 {
             fraction-digits 2;
           }
           units dB/km;
       mandatory true ;
       description "loss coefficient of the fiber";
         }
         leaf total-loss {
           type decimal64 {
             fraction-digits 2;
           }
           units dB;
       mandatory true ;
           description
             "includes all losses: fiber loss and conn-in and
              conn-out losses";
         }
         leaf pmd{
           type decimal64 {
             fraction-digits 2;
           }
           units sqrt(ps);
       description "pmd of the fiber";
         }
         leaf conn-in{

Lee, et al.              Expires January 9, 2022               [Page 39]
Internet-Draft    Opt. Impairment-Aware Topo YANG Model        July 2021

           type decimal64 {
             fraction-digits 2;
           }
           units dB;
       description "connector-in";
         }
         leaf conn-out{
           type decimal64 {
             fraction-digits 2;
           }
           units dB;
       description "connector-out";
         }
       }
     }

     grouping roadm-express-path {
       description
         "The optical impairments of a ROADM express path.";
       leaf roadm-pmd {
         type decimal64 {
           fraction-digits 8;
           range "0..max";
         }
         units "ps/(km)^0.5";
         description
           "Polarization Mode Dispersion";
       }
       leaf roadm-cd {
         type decimal64 {
           fraction-digits 5;
         }
         units "ps/nm";
         description "Chromatic Dispersion";
       }
       leaf roadm-pdl {
         type decimal64 {
           fraction-digits 2;
         }
         units dB ;
         description "Polarization dependent loss";
       }
       leaf roadm-inband-crosstalk {
         type decimal64 {
           fraction-digits 2;
         }
         units dB;
         description

Lee, et al.              Expires January 9, 2022               [Page 40]
Internet-Draft    Opt. Impairment-Aware Topo YANG Model        July 2021

           "In-band crosstalk, or coherent crosstalk, can occur in
             components that can have multiple same wavelength inputs
             with the inputs either routed to different output ports,
             or all but 1 blocked";
       }
       leaf roadm-maxloss {
         type decimal64 {
           fraction-digits 2;
         }
         units dB;
         description
           "This is the maximum expected add path loss from the
             ROADM ingress to the ROADM egress
             assuming no additional add path loss is added";
       }
     }

     grouping roadm-add-path {
       description "The optical impairments of a ROADM add path.";
       leaf roadm-pmd {
         type decimal64 {
           fraction-digits 8;
           range "0..max";
         }
         units "ps";
         description
           "Polarization Mode Dispersion";
       }
       leaf roadm-cd {
         type decimal64 {
           fraction-digits 5;
         }
         units "ps/nm";
         description "Cromatic Dispersion";
       }
       leaf roadm-pdl {
         type decimal64 {
           fraction-digits 2;
         }
         units dB ;
         description "Polarization dependent loss";
       }
       leaf roadm-inband-crosstalk {
         type decimal64 {
           fraction-digits 2;
         }
         units dB ;
         description

Lee, et al.              Expires January 9, 2022               [Page 41]
Internet-Draft    Opt. Impairment-Aware Topo YANG Model        July 2021

           "In-band crosstalk, or coherent crosstalk,
             can occur in components that can have multiple same
             wavelength inputs,with the inputs either
             routed to different output ports,
             or all but 1 blocked.
             In the case of add path it is the total
             of the add block
             + egress WSS crosstalk contributions.";
       }
       leaf roadm-maxloss {
         type decimal64 {
           fraction-digits 2;
         }
         units dB ;
         description
           "This is the maximum expected add path loss from
             the add/drop port input to the ROADM egress,
             assuming no additional add path loss is added.
             This is used to establish the minimum required
             transponder output power required
             to hit the ROADM egress target power
             levels and preventing
             to hit the WSS attenuation limits.
             If the add path contains an internal amplifier
             this loss value should be based
             on worst case expected amplifier gain due to
             ripple or gain uncertainty";
       }
       leaf roadm-pmax {
         type decimal64 {
           fraction-digits 2;
         }
         units dBm ;
         description
           "This is the maximum (per carrier) power level
             permitted at the add block input ports,
             that can be handled by the ROADM node.
             This may reflect either add amplifier power
             contraints or WSS adjustment limits.
             Higher power transponders would need to have
             their launch power reduced
             to this value or lower";
       }
       leaf roadm-osnr {
         type l0-types-ext:snr;
         description
           "Optical Signal-to-Noise Ratio (OSNR).
             If the add path contains the ability to adjust the

Lee, et al.              Expires January 9, 2022               [Page 42]
Internet-Draft    Opt. Impairment-Aware Topo YANG Model        July 2021

             carrier power levels into an add path amplifier
             (if present) to a target value,
             this reflects the OSNR contribution of the
             add amplifier assuming this target value is obtained.
             The worst case OSNR based on the input power and
             NF calculation method, and this value, should be used
             (if both are defined).";
       }
       leaf roadm-noise-figure {
         type decimal64 {
           fraction-digits 5;
         }
         units "dB";
         description
           "Noise Figure. If the add path contains an amplifier,
             this is the noise figure of that amplifier inferred
             to the add port.
             This permits add path OSNR calculation based
             on the input power levels to the add block
             without knowing the ROADM path losses to
             the add amplifier.";
       }
     }

     grouping roadm-drop-path {
       description "roadm drop block path optical impairments";
       leaf roadm-pmd {
         type decimal64 {
           fraction-digits 8;
           range "0..max";
         }
         units "ps/(km)^0.5";
         description
           "Polarization Mode Dispersion";
       }
       leaf roadm-cd {
         type decimal64 {
           fraction-digits 5;
         }
         units "ps/nm";
         description "Chromatic Dispersion";
       }
       leaf roadm-pdl {
         type decimal64 {
           fraction-digits 2;
         }
         units dB ;
         description "Polarization dependent loss";

Lee, et al.              Expires January 9, 2022               [Page 43]
Internet-Draft    Opt. Impairment-Aware Topo YANG Model        July 2021

       }
       leaf roadm-inband-crosstalk {
         type decimal64 {
           fraction-digits 2;
         }
         units dB;
         description
           "In-band crosstalk, or coherent crosstalk, can occur in
             components that can have multiple same wavelength
             inputs,with the inputs either routed to different
             output ports,or all but 1 blocked.
             In the case of drop path it is the total
             of the ingress
             to drop e.g. WSS and drop block crosstalk
             contributions.";
       }
       leaf roadm-maxloss {
         type decimal64 {
           fraction-digits 2;
         }
         units dB ;
         description
           "The net loss from the ROADM input,to the output
             of the drop block.
             If ROADM ingress to drop path includes an amplifier,
             the amplifier gain reduces the net loss.
             This is before any additional drop path attenuation
             that may be required
             due to drop amplifier power contraints.
             The max value correspond to worst case expected loss,
             including amplifier gain ripple or uncertainty.
             It is the maximum output power of the drop
             amplifier.";
       }
       leaf roadm-minloss {
         type decimal64 {
           fraction-digits 2;
         }
         units dB ;
         description
           "The net loss from the ROADM input, to the
             output of the drop block.
             If this ROADM ingress to drop path includes
             an amplifier,the amplifier gain reduces the net loss.
             This is before any additional drop path attenuation
             that may be required due to drop amplifier power
             contraints.
             The min value correspond to best case expected loss,

Lee, et al.              Expires January 9, 2022               [Page 44]
Internet-Draft    Opt. Impairment-Aware Topo YANG Model        July 2021

             including amplifier gain ripple or uncertainty.";
       }
       leaf roadm-typloss {
         type decimal64 {
           fraction-digits 2;
         }
         units dB ;
         description
           "The net loss from the ROADM input,
             to the output of the drop block.
             If this ROADM ingress to drop path
             includes an amplifier,
             the amplifier gain reduces the net loss.
             This is before any additional drop path
             attenuation
             that may be required due to drop amplifier
             power contraints.
             The typ value correspond to typical case
             expected loss.";
       }
       leaf roadm-pmin {
         type decimal64 {
           fraction-digits 2;
         }
         units dBm ;
         description
           "If the drop path has additional loss
             that is added, for example,
             to hit target power levels into a
             drop path amplifier, or simply, to reduce the
             power of a strong carrier
             (due to ripple,for example),
             then the use of the ROADM input power levels and
             the above drop losses is not appropriate.
             This parameter corresponds to the min per
             carrier power levels
             expected at the output of the drop block.
             A detail example of the comparison using
             these parameters is
             detailed in section xxx of the document yyy.";
       }
       leaf roadm-pmax {
         type decimal64 {
           fraction-digits 2;
         }
         units dBm ;
         description
           "If the drop path has additional loss that is added,

Lee, et al.              Expires January 9, 2022               [Page 45]
Internet-Draft    Opt. Impairment-Aware Topo YANG Model        July 2021

             for example, to hit target power levels into a
             drop path amplifier,or simply,to reduce the power
             of a strong carrier(due to ripple,for example),
             then the use of the ROADM input power levels and the
             above drop losses is not appropriate.
             This parameter corresponds to the best case per
             carrier power levels expected at the output of the
             drop block.
             A detail example of the comparison using
             these parameters
             is detailed in section xxx of the document yyy";
       }
       leaf roadm-ptyp {
         type decimal64 {
           fraction-digits 2;
         }
         units dBm ;
         description
           "If the drop path has additional loss that is added,
             for example, to hit target power levels into a
             drop path amplifier,or simply,to reduce the
             power of a strong carrier(due to ripple,for example),
             then the use of the ROADM input power levels and
             the above drop losses is not appropriate.
             This parameter corresponds to the typical case
             per carrier power levels expected
             at the output of the drop block.";
       }
       leaf roadm-osnr {
         type l0-types-ext:snr;
         description
           "Optical Signal-to-Noise Ratio (OSNR).
             Expected OSNR contribution of the drop path
             amplifier(if present)
             for the case of additional drop path loss
             (before this amplifier)
             in order to hit a target power level (per carrier).
             If both, the OSNR based on the ROADM
             input power level
             (Pcarrier =
             Pref+10Log(carrier-baudrate/ref-baud) + delta-power)
             and the input inferred NF(NF.drop),
             and this OSNR value, are defined,
             the minimum value between these two should be used";
       }
       leaf roadm-noise-figure {
         type decimal64 {
           fraction-digits 5;

Lee, et al.              Expires January 9, 2022               [Page 46]
Internet-Draft    Opt. Impairment-Aware Topo YANG Model        July 2021

         }
         units "dB";
         description
           "Drop path Noise Figure.
             If the drop path contains an amplifier,
             this is the noise figure
             of that amplifier, inferred to the
             ROADM ingress port.
             This permits to determine
             amplifier OSNR contribution
             without having to specify the
             ROADM node's losses to that amplifier.
             This applies for the case of no
             additional drop path loss,
             before the amplifier, in order to reduce the power
             of the carriers to a target value";
       }
     }

     grouping concentratedloss-params{
       description "concentrated loss";
       container concentratedloss{
       description "concentrated loss";
         leaf loss {
           type decimal64 {
             fraction-digits 2;
           }
           units dB ;
           mandatory true;
           description "..";
         }
       }
     }

     grouping power-param{
       description
         "optical power or PSD after the ROADM or after the out-voa";
       choice power-param {
         description
           "select the mode: channel power or power spectral density";
         case channel-power {
           when "/nw:networks/nw:network/nt:link/tet:te
               /tet:te-link-attributes/OMS-attributes
               /equalization-mode='carrier-power'";
           leaf nominal-carrier-power{
             type decimal64 {
                 fraction-digits 2;
             }

Lee, et al.              Expires January 9, 2022               [Page 47]
Internet-Draft    Opt. Impairment-Aware Topo YANG Model        July 2021

             units dBm ;
             description
               " Reference channel power. Same grouping is used for the
               OMS power after the ROADM (input of the OMS) or after the
               out-voa of each amplifier. ";
           }
         }
         case power-spectral-density{
           when "/nw:networks/nw:network/nt:link/tet:te
               /tet:te-link-attributes/OMS-attributes
               /equalization-mode='power-spectral-density'";
           leaf nominal-power-spectral-density{
             type decimal64 {
                 fraction-digits 16;
             }
             units W/Hz ;
             description
               " Reference power spectral density after
                 the ROADM or after the out-voa.
                 Typical value : 3.9 E-14, resolution 0.1nW/MHz";
           }
         }
       }
     }

     grouping oms-general-optical-params {
       description "OMS link optical parameters";
       leaf generalized-snr {
         type l0-types-ext:snr;
         description "generalized snr";
       }
       leaf equalization-mode{
         type identityref {
           base l0-types-ext:type-power-mode;
         }
         mandatory true;
         description "equalization mode";
       }
       uses power-param;
     }

     grouping otsi-group {
       description "OTSiG definition , representing client
        digital information stream supported by 1 or more OTSi";

       list otsi {
         key "otsi-carrier-id";
         config false;

Lee, et al.              Expires January 9, 2022               [Page 48]
Internet-Draft    Opt. Impairment-Aware Topo YANG Model        July 2021

         description
           "list of OTSi contained in 1 OTSiG.
           The list could also be of only 1 element";
         leaf otsi-carrier-id {
           type int16;
           description "OTSi carrier-id";
         }

   /*any OTSi as signal generated by transceiver and*/
   /* attached to a transponder.*/

         leaf transponder-ref {
           type leafref {
             path "../../../../../transponder/transponder-id";
           }
           description
             "Reference to the configured transponder";
         }
         leaf transceiver-ref {
           type leafref {
             path "deref(../transponder-ref)/../transceiver/" +
                  "transceiver-id";
           }
           description
             "Reference to the configured transceiver " ;
         }
         leaf configured-mode {
           type leafref {
             path "deref(../transceiver-ref)/../supported-modes/" +
                  "supported-mode/mode-id";
           }
           description
             "Reference to the configured mode for transceiver
              compatibility approach";
         }
         uses l0-types-ext:common-transceiver-configured-param;
       } // OTSi list
     } // OTSiG grouping

     grouping media-channel-groups {
       description "media channel groups";
       list media-channel-group {
       key "i";
         description
           "list of media channel groups";
         leaf i {
           type int16;

Lee, et al.              Expires January 9, 2022               [Page 49]
Internet-Draft    Opt. Impairment-Aware Topo YANG Model        July 2021

             description "index of media channel group member";
         }

         list media-channels {
           key "flexi-n";
           description
             "list of media channels represented as (n,m)";

    // this grouping add both n.m values
           uses l0-types:flexi-grid-frequency-slot;

           leaf otsi-group-ref {
             type leafref {
               path "/nw:networks/nw:network/nw:node/tet:te" +
                   "/tet:tunnel-termination-point" +
                   "/otsi-group/otsi-group-id" ;
               }
             description
               "Reference to the otsi-group list to get otsi-group
               identifier of the
               OTSiG carried by this media channel
               that reports the transient stat";
           }
           leaf otsi-ref {
             type leafref {
               path "/nw:networks/nw:network/nw:node/tet:te" +
                   "/tet:tunnel-termination-point/"
                  +"otsi-group[otsi-group-id=current()"
                  +"/../otsi-group-ref]/"
                  + "otsi/otsi-carrier-id" ;
             }
             description
                "Reference to the otsi list supporting
                the related OTSiG to get otsi identifier";
           }
           leaf delta-power{
             type decimal64 {
                 fraction-digits 2;
             }
             units dB ;
             description
               " Deviation from the reference carrier power defined for
               the OMS.";
           }
         } // media channels list
       } // media-channel-groups list
     } // media media-channel-groups grouping

Lee, et al.              Expires January 9, 2022               [Page 50]
Internet-Draft    Opt. Impairment-Aware Topo YANG Model        July 2021

     grouping oms-element {
       description "OMS description";
       list OMS-elements {
           key "elt-index";
           description
             "defines the spans and the amplifier blocks of
             the amplified lines";
           leaf elt-index {
             type uint16;
             description
               "ordered list of Index of OMS element
               (whether it's a Fiber, an EDFA or a
   Concentratedloss)";
           }
           leaf oms-element-uid {
             type string;
             description
               "unique id of the element if it exists";
           }

             choice element {
               mandatory true;
               description "OMS element type";
               case amplifier {
                 uses amplifier-params ;
               }
               case fiber {
                 uses fiber-params ;
               }
               case concentratedloss {
                 uses concentratedloss-params ;
               }
             }

       }
     }

   /* Data nodes */

     augment "/nw:networks/nw:network/nw:network-types"
           + "/tet:te-topology" {
      description "optical-impairment topology augmented";
      container optical-impairment-topology {
        presence "indicates an impairment-aware topology of
        optical networks";
        description
        "Container to identify impairment-aware topology type";
      }

Lee, et al.              Expires January 9, 2022               [Page 51]
Internet-Draft    Opt. Impairment-Aware Topo YANG Model        July 2021

     }

     augment "/nw:networks/nw:network/nw:node" {
       when "../nw:network-types/tet:te-topology" +
            "/optical-imp-topo:optical-impairment-topology" {
         description
           "This augment is only valid for Optical Impairment.";
       }
       description
         "Node augmentation for optical impairments data.";
       list transponder {
         key "transponder-id";
         config false;
         description "list of transponder";
         leaf transponder-id {
           type uint32;
           description "transponder identifier";
         }

         list transceiver {
           key "transceiver-id";
           config false;
           description "list of transceiver related to a transponder";
           leaf transceiver-id {
             type uint32;
             description "transceiver identifier";
           }
           leaf termination-type-capabilities {
             type enumeration {
               enum tunnel-only {
                 description
                   "The transceiver can only be used in an Optical
                   Tunnel termination configuration.";
               }
               enum 3r-only {
                 description
                   "The transceiver can only be used in a 3R
                   configuration.";
               }
               enum 3r-or-tunnel {
                 description
                   "The transceiver can be configure to be used either
                   in an Optical Tunnel termination configuration or in
                   a 3R configuration.";
               }
             }
             description
               "Describes whether the tranceiver can be used in an

Lee, et al.              Expires January 9, 2022               [Page 52]
Internet-Draft    Opt. Impairment-Aware Topo YANG Model        July 2021

               Optical Tunnel termination configuration or in a 3R
               configuration (or both).";
           }
           leaf supported-3r-mode {
             when '(../termination-type-capabilities = "3r-only") or
                   (../termination-type-capabilities = "3r-or-tunnel")'
                   {
               description
                 "Applies only when the tranceiver supports 3R
                 configuration.";
             }
             type enumeration {
               enum unidir {
                 description
                   "Unidirectional 3R configuration.";
               }
               enum bidir {
                 description
                   "Bidirectional 3R configuration.";
               }
             }
             description
               "Describes the supported 3R configuration type.";
           }
           leaf configured-termination-type {
             type enumeration {
               enum tunnel-termination {
                 description
                   "The transceiver is currently used in an Optical
                   Tunnel termination configuration.";
               }
               enum 3r-regeneration {
                 description
                   "The transceiver is currently used in a 3R
                   configuration.";
               }
             }
             description
               "Describes whether the current configuration of the
               tranceiver is used in an Optical Tunnel termination
               configuration or in a 3R configuration.

               If empty, it means that the transcevier is not used.";
           }
           uses l0-types-ext:transceiver-capabilities;
         } // end of list of transceiver
       } // end list of transponder
     }

Lee, et al.              Expires January 9, 2022               [Page 53]
Internet-Draft    Opt. Impairment-Aware Topo YANG Model        July 2021

     augment "/nw:networks/nw:network/nt:link/tet:te"
           + "/tet:te-link-attributes"   {
       when "/nw:networks/nw:network/nw:network-types"
          + "/tet:te-topology/"
          + "optical-imp-topo:optical-impairment-topology" {
         description
           "This augment is only valid for Optical Impairment.";
       }
       description "Optical Link augmentation for impairment data.";
       container OMS-attributes {
         config false;
         description "OMS attributes";
         uses oms-general-optical-params;
         uses media-channel-groups;
         uses oms-element;
       }
     }

     augment "/nw:networks/nw:network/nw:node/tet:te"
           + "/tet:tunnel-termination-point" {
       when "/nw:networks/nw:network/nw:network-types"
          + "/tet:te-topology/"
          + "optical-imp-topo:optical-impairment-topology" {
         description
           "This augment is only valid for Impairment with
            non-sliceable transponder model";
       }
       description
         "Tunnel termination point augmentation for non-sliceable
          transponder model.";

       list otsi-group {
         key "otsi-group-id";
         config false;
         description
           "the list of possible OTSiG representing client digital
           stream";
         leaf otsi-group-id {
           type int16;
           description "index of otsi-group element";
         }
         uses otsi-group;
       } // list of OTSiG
       list transceiver {
         config false;
         description
           "The list of the tranceivers used by the TTP.";
         leaf transponder-ref {

Lee, et al.              Expires January 9, 2022               [Page 54]
Internet-Draft    Opt. Impairment-Aware Topo YANG Model        July 2021

           type leafref {
             path "../../../../transponder/transponder-id";
           }
           description
             "The reference to the transponder hosting the tranceiver
             of the TTP.";
         }
         leaf tranceiver-ref {
           type leafref {
             path "deref(../transponder-ref)/../transceiver" +
                  "/transceiver-id";
           }
           description
             "The reference to the tranceiver of the TTP.";
         }
       } // list of tranceivers
     } // end of augment

     augment "/nw:networks/nw:network/nw:node/tet:te"
      + "/tet:tunnel-termination-point" {
      when "/nw:networks/nw:network/nw:network-types"
       +"/tet:te-topology/"
       + "optical-imp-topo:optical-impairment-topology" {
       description
         "This augment is only valid for optical impairment
          with sliceable transponder model";
      }
      description
        "Tunnel termination point augmentation for sliceable
         transponder model.";
      uses sliceable-transponder-attributes;
     }

     augment "/nw:networks/nw:network/nw:node/tet:te"
           + "/tet:te-node-attributes" {
       when "/nw:networks/nw:network/nw:network-types"
          + "/tet:te-topology"
          + "/optical-imp-topo:optical-impairment-topology" {

         description
           "This augment is only valid for Optical Impairment
           topology";
       }
       description
         "node attributes augmentantion for optical-impairment ROADM
          node";

       list roadm-path-impairments {

Lee, et al.              Expires January 9, 2022               [Page 55]
Internet-Draft    Opt. Impairment-Aware Topo YANG Model        July 2021

         key "roadm-path-impairments-id";
         config false;
         description
           "The set of optical impairments related to a ROADM path.";

         leaf roadm-path-impairments-id {
           type uint32;
           description "index of the ROADM path-impairment list";
         }
         choice impairment-type {
           description "type path impairment";
           case roadm-express-path {
             list roadm-express-path {
               description
                 "The list of optical impairments on a ROADM express
                 path for different frequency ranges.

                 Two elements in the list must not have the same range
                 or overlapping ranges.";
               container frequency-range {
                 description
                   "The frequency range for which these optical
                   impairments apply.";
                 uses l0-types-ext:frequency-range;
               }
               uses roadm-express-path;
             }
           }
           case roadm-add-path {
             list roadm-add-path {
               description
                 "The list of optical impairments on a ROADM add
                 path for different frequency ranges.

                 Two elements in the list must not have the same range
                 or overlapping ranges.";
               container frequency-range {
                 description
                   "The frequency range for which these optical
                   impairments apply.";
                 uses l0-types-ext:frequency-range;
               }
               uses roadm-add-path;
             }
           }
           case roadm-drop-path {
             list roadm-drop-path {
               description

Lee, et al.              Expires January 9, 2022               [Page 56]
Internet-Draft    Opt. Impairment-Aware Topo YANG Model        July 2021

                 "The list of optical impairments on a ROADM add
                 path for different frequency ranges.

                 Two elements in the list must not have the same range
                 or overlapping ranges.";
               container frequency-range {
                 description
                   "The frequency range for which these optical
                   impairments apply.";
                 uses l0-types-ext:frequency-range;
               }
               uses roadm-drop-path;
             }
           }
         }
       } // list path impairments
     } // augmentation for optical-impairment ROADM

     augment "/nw:networks/nw:network/nw:node/tet:te/"
           + "tet:information-source-entry/tet:connectivity-matrices"{
       when "/nw:networks/nw:network/nw:network-types"
          + "/tet:te-topology/"
          + "optical-imp-topo:optical-impairment-topology" {
         description
           "This augment is only valid for Optical Impairment
           topology ";
       }

       description
         "Augment default TE node connectivity matrix information
         source.";

       leaf roadm-path-impairments {
         type leafref {
           path "../../../tet:te-node-attributes/"
           + "roadm-path-impairments/roadm-path-impairments-id";
         }
         description "pointer to the list set of ROADM optical
         impairments";
       }
     } // augmentation connectivity-matrices information-source

     augment "/nw:networks/nw:network/nw:node/tet:te/"
           + "tet:information-source-entry/tet:connectivity-matrices/"
           + "tet:connectivity-matrix" {
       when "/nw:networks/nw:network/nw:network-types"
          + "/tet:te-topology/"
          + "optical-imp-topo:optical-impairment-topology" {

Lee, et al.              Expires January 9, 2022               [Page 57]
Internet-Draft    Opt. Impairment-Aware Topo YANG Model        July 2021

         description
           "This augment is only valid for Optical Impairment
            topology ";
       }

       description
         "Augment TE node connectivity matrix entry information
         source.";

       leaf roadm-path-impairments {
         type leafref {
           path "../../../../tet:te-node-attributes/"
           + "roadm-path-impairments/roadm-path-impairments-id";
         }
         description "pointer to the list set of ROADM optical
         impairments";
       }
     } // augmentation connectivity-matrix information-source

     augment "/nw:networks/nw:network/nw:node/tet:te/"
           + "tet:te-node-attributes/tet:connectivity-matrices" {
       when "/nw:networks/nw:network/nw:network-types"
          + "/tet:te-topology/"
          + "optical-imp-topo:optical-impairment-topology" {
         description
           "This augment is only valid for Optical Impairment
           topology ";
       }

       description
         "Augment default TE node connectivity matrix.";
       leaf roadm-path-impairments {
         type leafref {
           path "../../roadm-path-impairments/"
           + "roadm-path-impairments-id";
         }
         config false; /*the identifier in the list */
          /*"roadm-path-impairments" of ROADM optical impairment*/
                       /*is read-only as the rest of attributes*/
         description "pointer to the list set of ROADM optical
         impairments";
       }
     } // augmentation connectivity-matrices

     augment "/nw:networks/nw:network/nw:node/tet:te/"
           + "tet:te-node-attributes/"
           + "tet:connectivity-matrices/tet:connectivity-matrix" {
       when "/nw:networks/nw:network/nw:network-types"

Lee, et al.              Expires January 9, 2022               [Page 58]
Internet-Draft    Opt. Impairment-Aware Topo YANG Model        July 2021

          + "/tet:te-topology/"
          + "optical-imp-topo:optical-impairment-topology" {
         description
           "This augment is only valid for
           Optical Impairment topology ";
       }

       description
         "Augment TE node connectivity matrix entry.";

       leaf roadm-path-impairments {
         type leafref {
           path "../../../roadm-path-impairments/"
           + "roadm-path-impairments-id";
         }
         config false;
         description "pointer to the list set of ROADM optical
          impairments";
       }
     } // augmentation connectivity-matrix

     augment "/nw:networks/nw:network/nw:node/tet:te/"
           + "tet:tunnel-termination-point/"
           + "tet:local-link-connectivities" {

       when "/nw:networks/nw:network/nw:network-types"
          + "/tet:te-topology/"
          + "optical-imp-topo:optical-impairment-topology" {
         description
         "This augment is only valid for Optical Impairment topology ";
       }

       description
         "Augment default TTP LLC.";
       leaf add-path-impairments {
         type leafref {
           path "../../../tet:te-node-attributes/"
           + "roadm-path-impairments/roadm-path-impairments-id" ;
         }
         config false;
         description "pointer to the list set of ROADM optical
          impairments";
       }
       leaf drop-path-impairments {
         type leafref {
           path "../../../tet:te-node-attributes/"
           + "roadm-path-impairments/roadm-path-impairments-id" ;
         }

Lee, et al.              Expires January 9, 2022               [Page 59]
Internet-Draft    Opt. Impairment-Aware Topo YANG Model        July 2021

         config false;
         description "pointer to the list set of ROADM
         optical impairments";
       }
     } // augmentation local-link-connectivities

     augment "/nw:networks/nw:network/nw:node/tet:te/"
           + "tet:tunnel-termination-point/"
           + "tet:local-link-connectivities/"
           + "tet:local-link-connectivity" {

       when "/nw:networks/nw:network/nw:network-types"
          + "/tet:te-topology/"
          + "optical-imp-topo:optical-impairment-topology" {
         description
           "This augment is only valid for
            Optical Impairment topology ";
       }

       description
         "Augment TTP LLC entry.";
       leaf add-path-impairments {
         type leafref {
           path "../../../../tet:te-node-attributes/"
           + "roadm-path-impairments/roadm-path-impairments-id" ;
         }
         config false;
         description "pointer to the list set of ROADM optical
          impairments";
       }
       leaf drop-path-impairments {
         type leafref {
           path "../../../../tet:te-node-attributes/"
           + "roadm-path-impairments/roadm-path-impairments-id" ;
         }
         config false;
         description "pointer to the list set of ROADM optical
         impairments";
       }
     } // augmentation local-link-connectivity
   }
   <CODE ENDS>

Lee, et al.              Expires January 9, 2022               [Page 60]
Internet-Draft    Opt. Impairment-Aware Topo YANG Model        July 2021

5.  Security Considerations

   The configuration, state, and action data defined in this document
   are designed to be accessed via a management protocol with a secure
   transport layer, such as NETCONF [RFC6241].  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.

   A number of configuration data nodes defined in this document are
   read-only; however, these data nodes may be considered sensitive or
   vulnerable in some network environments (TBD).

6.  IANA Considerations

   This document registers the following namespace URIs in the IETF XML
   registry [RFC3688]:

   --------------------------------------------------------------------
   URI: urn:ietf:params:xml:ns:yang:ietf-optical-impairment-topology
   Registrant Contact: The IESG.
   XML: N/A, the requested URI is an XML namespace.
   --------------------------------------------------------------------

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

   --------------------------------------------------------------------
   name:      ietf-optical-impairment-topology
   namespace: urn:ietf:params:xml:ns:yang:ietf-optical-impairment-
   topology
   prefix:    optical-imp-topo
   reference: RFC XXXX (TDB)
   --------------------------------------------------------------------

7.  Acknowledgments

   We thank Daniele Ceccarelli and Oscar G.  De Dios for useful
   discussions and motivation for this work.

8.  References

8.1.  Normative References

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

Lee, et al.              Expires January 9, 2022               [Page 61]
Internet-Draft    Opt. Impairment-Aware Topo YANG Model        July 2021

   [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>.

   [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>.

   [RFC8795]  Liu, X., Bryskin, I., Beeram, V., Saad, T., Shah, H., and
              O. Gonzalez de Dios, "YANG Data Model for Traffic
              Engineering (TE) Topologies", RFC 8795,
              DOI 10.17487/RFC8795, August 2020,
              <https://www.rfc-editor.org/info/rfc8795>.

8.2.  Informative References

   [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>.

   [RFC6566]  Lee, Y., Ed., Bernstein, G., Ed., Li, D., and G.
              Martinelli, "A Framework for the Control of Wavelength
              Switched Optical Networks (WSONs) with Impairments",
              RFC 6566, DOI 10.17487/RFC6566, March 2012,
              <https://www.rfc-editor.org/info/rfc6566>.

   [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, February 2015,
              <https://www.rfc-editor.org/info/rfc7446>.

   [RFC7579]  Bernstein, G., Ed., Lee, Y., Ed., Li, D., Imajuku, W., and
              J. Han, "General Network Element Constraint Encoding for
              GMPLS-Controlled Networks", RFC 7579,
              DOI 10.17487/RFC7579, June 2015,
              <https://www.rfc-editor.org/info/rfc7579>.

Lee, et al.              Expires January 9, 2022               [Page 62]
Internet-Draft    Opt. Impairment-Aware Topo YANG Model        July 2021

   [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, June 2015,
              <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, November 2015,
              <https://www.rfc-editor.org/info/rfc7698>.

   [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>.

   [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>.

   [RFC8345]  Clemm, A., Medved, J., Varga, R., Bahadur, N.,
              Ananthakrishnan, H., and X. Liu, "A YANG Data Model for
              Network Topologies", RFC 8345, DOI 10.17487/RFC8345, March
              2018, <https://www.rfc-editor.org/info/rfc8345>.

   [RFC8453]  Ceccarelli, D., Ed. and Y. Lee, Ed., "Framework for
              Abstraction and Control of TE Networks (ACTN)", RFC 8453,
              DOI 10.17487/RFC8453, August 2018,
              <https://www.rfc-editor.org/info/rfc8453>.

   [I-D.ietf-ccamp-wson-yang]
              Zheng, H., Lee, Y., Guo, A., Lopez, V., and D. King, "A
              YANG Data Model for WSON (Wavelength Switched Optical
              Networks)", draft-ietf-ccamp-wson-yang-28 (work in
              progress), December 2020.

   [I-D.ietf-ccamp-layer0-types]
              Zheng, H., Lee, Y., Guo, A., Lopez, V., and D. King, "A
              YANG Data Model for Layer 0 Types", draft-ietf-ccamp-
              layer0-types-09 (work in progress), December 2020.

   [I-D.esdih-ccamp-layer0-types-ext]
              Beller, D., Belotti, S., Zheng, H., Busi, I., and E. L.
              Rouzic, "A YANG Data Model for Layer 0 Types - Revision
              2", draft-esdih-ccamp-layer0-types-ext-01 (work in
              progress), July 2021.

Lee, et al.              Expires January 9, 2022               [Page 63]
Internet-Draft    Opt. Impairment-Aware Topo YANG Model        July 2021

   [I-D.ietf-ccamp-dwdm-if-param-yang]
              Galimberti, G., Kunze, R., Burk, A., Hiremagalur, D., and
              G. Grammel, "A YANG model to manage the optical interface
              parameters for an external transponder in a WDM network",
              draft-ietf-ccamp-dwdm-if-param-yang-05 (work in progress),
              November 2020.

   [G.807]    "Generic functional architecture of the optical media
              network", ITU-T Recommendation G.807 - in publication
              process, February 2020.

   [G.709]    "Interfaces for the Optical Transport Network (OTN)",
              ITU-T Recommendation G.709, June 2016.

   [G.694.1]  "Spectral grids for WDM applications: DWDM frequency
              grid", ITU-T Recommendation G.694.1, February 2012.

   [G.959.1]  "Optical transport network physical layer interfaces",
              ITU-T Recommendation G.959.1, February 2012.

   [G.872]    "Architecture of optical transport networks",
              ITU-T Recommendation G.872, January 2017.

   [G.698.2]  "Amplified multichannel dense wavelength division
              multiplexing applications with single channel optical
              interfaces", ITU-T Recommendation G.698.2, November 2018.

   [G.798.1]  "Types and characteristics of optical transport network
              equipment", ITU-T Recommendation G.798.1, January 2013.

Appendix A.  Contributors

   Aihua Guo
   Huawei Technologies

   Email: aguo@futurewei.com

   Jonas Martensson
   RISE

   Email: jonas.martensson@ri.se

Lee, et al.              Expires January 9, 2022               [Page 64]
Internet-Draft    Opt. Impairment-Aware Topo YANG Model        July 2021

Appendix B.  Additional Authors

   Haomian Zheng
   Huawei Technologies

   Email: zhenghaomian@huawei.com

   Italo Busi
   Huawei Technologies

   Email: Italo.Busi@huawei.com

   Nicola Sambo
   Scuola Superiore Sant'Anna

   Email: nicosambo@gmail.com

   Giovanni Martinelli
   Cisco

   Email: giomarti@cisco.com

   Jean-Luc Auge
   Orange

   Email: jeanluc.auge@orange.com

   Julien Meuric
   Orange

   Email: julien.meuric@orange.com

   Sergio Belotti
   Nokia

   Email: Sergio.belotti@nokia.com

   Griseri Enrico
   Nokia

   Email: Enrico.Griseri@nokia.com

Lee, et al.              Expires January 9, 2022               [Page 65]
Internet-Draft    Opt. Impairment-Aware Topo YANG Model        July 2021

   Gert Grammel
   Juniper

   Email: ggrammel@juniper.net

Authors' Addresses

   Young Lee
   Samsung Electronics

   Email: younglee.tx@gmail.com

   Esther Le Rouzic
   Orange

   Email: esther.lerouzic@orange.com

   Victor Lopez
   Nokia

   Email: Victor.Lopez@nokia.com

   G. Galimberti
   Cisco

   Email: ggalimbe@cisco.com

   Dieter Beller
   Nokia

   Email: Dieter.Beller@nokia.com

Lee, et al.              Expires January 9, 2022               [Page 66]