Internet-Draft A YANG Data Model for WDM Tunnels October 2023
Guo, et al. Expires 25 April 2024 [Page]
Workgroup:
CCAMP Working Group
Internet-Draft:
draft-bgk-ccamp-merged-wdm-tunnel-00
Published:
Intended Status:
Standards Track
Expires:
Authors:
A. Guo
Futurewei Technologies
S. Belotti
Nokia
G. Galimberti
Individual
J.E.L.d.V. Mendez
Naudit HPCN
D.P. Burrero
Universidad Autonoma de Madrid

A YANG Data Model for WDM Tunnels

Abstract

This document defines a YANG data model for the provisioning and management of Traffic Engineering (TE) tunnels and Label Switched Paths (LSPs) in Optical Networks (Wavelength Switched Optical Networks (WSON) and Flexi-Grid Dense Wavelength Division Multiplexing (DWDM) Networks).

The YANG data model defined in this document conforms to the Network Management Datastore Architecture (NMDA).

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 25 April 2024.

1. Introduction

Transport networks have evolved from traditional Wavelength Switched Optical Networks (WSON) systems [RFC6163] based on only fixed-grid wavelength switching, towards elastic optical networks, based on flexi-grid Dense Wavelength Division Multiplexing (DWDM) transmission and switching technologies [RFC7698]. Such technology aims at increasing transport network scalability and flexibility, allowing bandwidth usage optimization.

While [RFC9094] [I-D.ietf-ccamp-flexigrid-yang] focus on flexi-grid objects such as nodes, transponders and links, this document presents a YANG [RFC7950] model for the provisioning and management of Traffic Engineering (TE) tunnels and Label Switched Paths (LSPs) in DWDM Optical Networks, which can be Wavelength Switched Optical Networks (WSON) networks or Flexi-Grid Dense Wavelength Division Multiplexing (DWDM) Networks, or a mix of these two networks. This YANG module defines the path from a source transponder or node to the destination through several intermediate nodes in such a WDM optical network.

This document identifies the WDM tunnel components, parameters and their values, and characterizes the features and the performances of the WDM elements. An application example is provided towards the end of the document to understand their utility better.

2. Terminology

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.

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

Refer to [RFC7446] and [RFC7699] for the key terms used in this document.

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

  • server

  • augment

  • data model

  • data node

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

  • state data

3. Overview

The generic TE tunnel attributes, such as source and destination node addresses, source and destination tunnel termination points (TTPs), are already defined by the base data model in [I-D.ietf-teas-yang-te]. The present model defines a WDM tunnel by augmenting the base model with the following WDM technology-specific constructs:

  • Global WDM layer constraints that influence the TE path selection, e.g., whether wavelength conversion or regeneration is considered

  • Global transponder/transceiver configuration constraints, e.g., operational modes, tuning constraints of the transceiver

  • Global optical performance constraints, e.g. generalized Signal-to-noise (G-SNR) margin of a feasible optical path

  • Path-scope WDM layer constraints, e.g. identities of transceivers assigned to the primary or secondary path

  • List of links that defines the path

  • Other optical attributes

Each path can be a segment path (only defined by the source and destination nodes or link termination points) or an end-to-end path (additionally needs source and destination transponders). Therefore, all the attributes are optional to support both situations.

4. Example of Use

In order to explain how this model is used, the following example is provided. An optical network usually has multiple transponders, switches (nodes) and links. Figure 1 shows a simple topology, where two physical paths interconnect two optical transponders via a combination of both WSON and Flexi-grid wavelength switched nodes and links.

                              WDM Tunnel
        <===================================================>
                         WDM Primary Path
        <--------------------------------------------------->

   +----------+                                        +----------+
   |  Flexi-  |                                        |  Flexi-  |
   |   grid   |                                        |   grid   |
   |  node A  |                                        |  node E  |
   |          |        +------+        +------+        |          |
   |          | Link 1 |Flexi-| Link 2 | WSON | Link 3 |          |
   |          |<------>| grid |<------>|      |<------>|          |
   |......... |        |node B|        |node C|        | .........|
   | Trans- : |        +------+        +------+        | : Trans- |
   | ponder : |                                        | : ponder |
   |    A   : |              +----------+              | :    E   |
   |........: |     Link 4   |Flexi-grid|   Link 5     | :........|
   |          |              |    D     |              |          |
   |          |<------------>|   node   |<------------>|          |
   |          |              +----------+              |          |
   +----------+                                        +----------+

        <--------------------------------------------------->
                          WDM Secondary Path
Figure 1: Topology Example

To configure an end-to-end WDM tunnel to interconnect transponders A and E, first of all we have to populate the flexi-grid topology YANG model with all elements in the network:

  • We define the transponders within nodes A and E as tunnel termination points (TTPs) and provide their internal local link connectivity towards the node interfaces. We also provide nodes A and B identifiers, addresses and interfaces.

  • We do the same for the nodes B, C and D, providing their identifiers, addresses and interfaces, as well as the internal connectivity matrix between interfaces.

  • Then, we also define the links 1 to 5 that interconnect nodes, indicating which WSON or flexi-grid labels are available.

  • Other information, such as the slot frequency and granularity are also provided.

After the nodes, links and transponders have been defined using [I-D.ietf-ccamp-flexigrid-yang] and [RFC9094] we can configure the tunnel from the information we have stored in the flexi-grid topology, by querying which elements are available, and planning the resources that have to be provided on each situation, taking into account the global and path-specific WDM tunnel constraints. Note that every element in the flexi-grid topology has a reference, and this is the way in which they are called in the tunnel.

  • Depending on the case, it is possible to define either the source and destination node ports, or the source and destination node and transponder. In our case, we would define a network tunnel, with source transponder A and source node B, and destination transponder E and destination node C. Thus, we are going to follow path x.

  • Then, for each link in the path x, we indicate which channel we are going to use, providing information about the slots, and what nodes are connected.

  • Finally, the flexi-grid topology has to be updated with each element usage status each time a tunnel is created or torn down.

5. YANG Model for WDM Tunnel

5.1. YANG Tree

module: ietf-wdm-tunnel

  augment /te:te/te:tunnels/te:tunnel:
    +--rw wdm-constraint
       +--rw transceiver-constraint
       |  +--rw operational-modes*     string
       |  +--rw tx-tune-constraints
       |     +--rw min-central-frequency?    frequency-thz
       |     +--rw max-central-frequency?    frequency-thz
       |     +--rw transceiver-tunability?   frequency-ghz
       +--rw gsnr-margin?                   snr
       +--rw use-regen?                     boolean
       +--rw wavelength-conversion?         boolean
       +--rw bit-stuffing?                  boolean
       +--rw wavelength-assignment?         identityref
       +--rw guard-band-size?               l0-types:frequency-thz
       +--rw matching-fwd-rev-wavelength?   boolean
       +--rw allow-retuning?                boolean
       +--rw delta-power?
               l0-types:gain-in-db-or-null
  augment /te:te/te:tunnels/te:tunnel/te:primary-paths
            /te:primary-path/te:explicit-route-objects-always
            /te:route-object-exclude-always/te:type
            /te:numbered-node-hop/te:numbered-node-hop:
    +--rw path-in-transceiver
    |  +--rw transponder-id?        uint32
    |  +--rw transceivers* [lane-id]
    |  |  +--rw lane-id           uint8
    |  |  +--rw transceiver-id?   uint32
    |  +--rw operational-modes*     string
    |  +--rw tx-tune-constraints
    |     +--rw min-central-frequency?    frequency-thz
    |     +--rw max-central-frequency?    frequency-thz
    |     +--rw transceiver-tunability?   frequency-ghz
    +--rw path-out-transceiver
       +--rw transponder-id?        uint32
       +--rw transceivers* [lane-id]
       |  +--rw lane-id           uint8
       |  +--rw transceiver-id?   uint32
       +--rw operational-modes*     string
       +--rw tx-tune-constraints
          +--rw min-central-frequency?    frequency-thz
          +--rw max-central-frequency?    frequency-thz
          +--rw transceiver-tunability?   frequency-ghz
  augment /te:te/te:tunnels/te:tunnel/te:primary-paths
            /te:primary-path/te:primary-reverse-path
            /te:explicit-route-objects-always
            /te:route-object-exclude-always/te:type
            /te:numbered-node-hop/te:numbered-node-hop:
    +--rw path-in-transceiver
    |  +--rw transponder-id?        uint32
    |  +--rw transceivers* [lane-id]
    |  |  +--rw lane-id           uint8
    |  |  +--rw transceiver-id?   uint32
    |  +--rw operational-modes*     string
    |  +--rw tx-tune-constraints
    |     +--rw min-central-frequency?    frequency-thz
    |     +--rw max-central-frequency?    frequency-thz
    |     +--rw transceiver-tunability?   frequency-ghz
    +--rw path-out-transceiver
       +--rw transponder-id?        uint32
       +--rw transceivers* [lane-id]
       |  +--rw lane-id           uint8
       |  +--rw transceiver-id?   uint32
       +--rw operational-modes*     string
       +--rw tx-tune-constraints
          +--rw min-central-frequency?    frequency-thz
          +--rw max-central-frequency?    frequency-thz
          +--rw transceiver-tunability?   frequency-ghz
  augment /te:te/te:tunnels/te:tunnel/te:primary-paths
            /te:primary-path/te:computed-paths-properties
            /te:computed-path-properties/te:path-properties:
    +--ro estimated-gsnr?          snr
    +--ro estimated-eol-gsnr?      snr
    +--ro estimated-lowest-gsnr?   snr
  augment /te:te/te:tunnels/te:tunnel/te:primary-paths
            /te:primary-path/te:primary-reverse-path
            /te:computed-paths-properties/te:computed-path-properties
            /te:path-properties:
    +--ro estimated-gsnr?          snr
    +--ro estimated-eol-gsnr?      snr
    +--ro estimated-lowest-gsnr?   snr
  augment /te:te/te:tunnels/te:tunnel/te:secondary-paths
            /te:secondary-path/te:explicit-route-objects-always
            /te:route-object-exclude-always/te:type
            /te:numbered-node-hop/te:numbered-node-hop:
    +--rw path-in-transceiver
    |  +--rw transponder-id?        uint32
    |  +--rw transceivers* [lane-id]
    |  |  +--rw lane-id           uint8
    |  |  +--rw transceiver-id?   uint32
    |  +--rw operational-modes*     string
    |  +--rw tx-tune-constraints
    |     +--rw min-central-frequency?    frequency-thz
    |     +--rw max-central-frequency?    frequency-thz
    |     +--rw transceiver-tunability?   frequency-ghz
    +--rw path-out-transceiver
       +--rw transponder-id?        uint32
       +--rw transceivers* [lane-id]
       |  +--rw lane-id           uint8
       |  +--rw transceiver-id?   uint32
       +--rw operational-modes*     string
       +--rw tx-tune-constraints
          +--rw min-central-frequency?    frequency-thz
          +--rw max-central-frequency?    frequency-thz
          +--rw transceiver-tunability?   frequency-ghz
  augment /te:te/te:tunnels/te:tunnel/te:secondary-reverse-paths
            /te:secondary-reverse-path
            /te:explicit-route-objects-always
            /te:route-object-exclude-always/te:type
            /te:numbered-node-hop/te:numbered-node-hop:
    +--rw path-in-transceiver
    |  +--rw transponder-id?        uint32
    |  +--rw transceivers* [lane-id]
    |  |  +--rw lane-id           uint8
    |  |  +--rw transceiver-id?   uint32
    |  +--rw operational-modes*     string
    |  +--rw tx-tune-constraints
    |     +--rw min-central-frequency?    frequency-thz
    |     +--rw max-central-frequency?    frequency-thz
    |     +--rw transceiver-tunability?   frequency-ghz
    +--rw path-out-transceiver
       +--rw transponder-id?        uint32
       +--rw transceivers* [lane-id]
       |  +--rw lane-id           uint8
       |  +--rw transceiver-id?   uint32
       +--rw operational-modes*     string
       +--rw tx-tune-constraints
          +--rw min-central-frequency?    frequency-thz
          +--rw max-central-frequency?    frequency-thz
          +--rw transceiver-tunability?   frequency-ghz
  augment /te:te/te:tunnels/te:tunnel/te:secondary-paths
            /te:secondary-path/te:computed-paths-properties
            /te:computed-path-properties/te:path-properties:
    +--ro estimated-gsnr?          snr
    +--ro estimated-eol-gsnr?      snr
    +--ro estimated-lowest-gsnr?   snr
  augment /te:te/te:tunnels/te:tunnel/te:secondary-reverse-paths
            /te:secondary-reverse-path/te:computed-paths-properties
            /te:computed-path-properties/te:path-properties:
    +--ro estimated-gsnr?          snr
    +--ro estimated-eol-gsnr?      snr
    +--ro estimated-lowest-gsnr?   snr
  augment /te:te/te:lsps/te:lsp/te:lsp-actual-route-information:
    +--ro wdm-path-state
       +--ro gsnr?   l0-types:snr
  augment /te:te/te:globals/te:named-path-constraints
            /te:named-path-constraint/te:path-in-segment
            /te:label-restrictions/te:label-restriction:
    +--rw grid-type?    identityref
    +--rw priority?     uint8
    +--rw flexi-grid
       +--rw slot-width-granularity?   identityref
       +--rw min-slot-width-factor?    uint16
       +--rw max-slot-width-factor?    uint16
  augment /te:te/te:globals/te:named-path-constraints
            /te:named-path-constraint/te:path-out-segment
            /te:label-restrictions/te:label-restriction:
    +--rw grid-type?    identityref
    +--rw priority?     uint8
    +--rw flexi-grid
       +--rw slot-width-granularity?   identityref
       +--rw min-slot-width-factor?    uint16
       +--rw max-slot-width-factor?    uint16
  augment /te:te/te:tunnels/te:tunnel/te:primary-paths
            /te:primary-path/te:path-in-segment/te:label-restrictions
            /te:label-restriction:
    +--rw grid-type?    identityref
    +--rw priority?     uint8
    +--rw flexi-grid
       +--rw slot-width-granularity?   identityref
       +--rw min-slot-width-factor?    uint16
       +--rw max-slot-width-factor?    uint16
  augment /te:te/te:tunnels/te:tunnel/te:primary-paths
            /te:primary-path/te:path-out-segment
            /te:label-restrictions/te:label-restriction:
    +--rw grid-type?    identityref
    +--rw priority?     uint8
    +--rw flexi-grid
       +--rw slot-width-granularity?   identityref
       +--rw min-slot-width-factor?    uint16
       +--rw max-slot-width-factor?    uint16
  augment /te:te/te:tunnels/te:tunnel/te:primary-paths
            /te:primary-path/te:primary-reverse-path
            /te:path-in-segment/te:label-restrictions
            /te:label-restriction:
    +--rw grid-type?    identityref
    +--rw priority?     uint8
    +--rw flexi-grid
       +--rw slot-width-granularity?   identityref
       +--rw min-slot-width-factor?    uint16
       +--rw max-slot-width-factor?    uint16
  augment /te:te/te:tunnels/te:tunnel/te:primary-paths
            /te:primary-path/te:primary-reverse-path
            /te:path-out-segment/te:label-restrictions
            /te:label-restriction:
    +--rw grid-type?    identityref
    +--rw priority?     uint8
    +--rw flexi-grid
       +--rw slot-width-granularity?   identityref
       +--rw min-slot-width-factor?    uint16
       +--rw max-slot-width-factor?    uint16
  augment /te:te/te:tunnels/te:tunnel/te:secondary-paths
            /te:secondary-path/te:path-in-segment
            /te:label-restrictions/te:label-restriction:
    +--rw grid-type?    identityref
    +--rw priority?     uint8
    +--rw flexi-grid
       +--rw slot-width-granularity?   identityref
       +--rw min-slot-width-factor?    uint16
       +--rw max-slot-width-factor?    uint16
  augment /te:te/te:tunnels/te:tunnel/te:secondary-paths
            /te:secondary-path/te:path-out-segment
            /te:label-restrictions/te:label-restriction:
    +--rw grid-type?    identityref
    +--rw priority?     uint8
    +--rw flexi-grid
       +--rw slot-width-granularity?   identityref
       +--rw min-slot-width-factor?    uint16
       +--rw max-slot-width-factor?    uint16
  augment /te:te/te:tunnels/te:tunnel/te:secondary-reverse-paths
            /te:secondary-reverse-path/te:path-in-segment
            /te:label-restrictions/te:label-restriction:
    +--rw grid-type?    identityref
    +--rw priority?     uint8
    +--rw flexi-grid
       +--rw slot-width-granularity?   identityref
       +--rw min-slot-width-factor?    uint16
       +--rw max-slot-width-factor?    uint16
  augment /te:te/te:tunnels/te:tunnel/te:secondary-reverse-paths
            /te:secondary-reverse-path/te:path-out-segment
            /te:label-restrictions/te:label-restriction:
    +--rw grid-type?    identityref
    +--rw priority?     uint8
    +--rw flexi-grid
       +--rw slot-width-granularity?   identityref
       +--rw min-slot-width-factor?    uint16
       +--rw max-slot-width-factor?    uint16
  augment /te:te/te:globals/te:named-path-constraints
            /te:named-path-constraint
            /te:explicit-route-objects-always
            /te:route-object-exclude-always/te:type/te:label
            /te:label-hop/te:te-label/te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw (fixed-single-or-super-channel)?
          |     +--:(single)
          |     |  +--rw dwdm-n?               l0-types:dwdm-n
          |     +--:(multi)
          |        +--rw subcarrier-dwdm-n*    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?                     l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw (single-or-super-channel)?
                +--:(single)
                |  +--rw flexi-n?              l0-types:flexi-n
                |  +--rw flexi-m?              l0-types:flexi-m
                x--:(super)
                |  +--rw subcarrier-flexi-n* [flexi-n]
                |     +--rw flexi-n    l0-types:flexi-n
                |     +--rw flexi-m?   l0-types:flexi-m
                +--:(multi)
                   +--rw frequency-slots
                      +--rw frequency-slot* [flexi-n]
                         +--rw flexi-n    l0-types:flexi-n
                         +--rw flexi-m?   l0-types:flexi-m
  augment /te:te/te:globals/te:named-path-constraints
            /te:named-path-constraint
            /te:explicit-route-objects-always
            /te:route-object-include-exclude/te:type/te:label
            /te:label-hop/te:te-label/te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw (fixed-single-or-super-channel)?
          |     +--:(single)
          |     |  +--rw dwdm-n?               l0-types:dwdm-n
          |     +--:(multi)
          |        +--rw subcarrier-dwdm-n*    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?                     l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw (single-or-super-channel)?
                +--:(single)
                |  +--rw flexi-n?              l0-types:flexi-n
                |  +--rw flexi-m?              l0-types:flexi-m
                x--:(super)
                |  +--rw subcarrier-flexi-n* [flexi-n]
                |     +--rw flexi-n    l0-types:flexi-n
                |     +--rw flexi-m?   l0-types:flexi-m
                +--:(multi)
                   +--rw frequency-slots
                      +--rw frequency-slot* [flexi-n]
                         +--rw flexi-n    l0-types:flexi-n
                         +--rw flexi-m?   l0-types:flexi-m
  augment /te:te/te:globals/te:named-path-constraints
            /te:named-path-constraint/te:path-in-segment
            /te:label-restrictions/te:label-restriction
            /te:label-start/te:te-label/te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw dwdm-n?    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?    l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw flexi-n?   l0-types:flexi-n
  augment /te:te/te:globals/te:named-path-constraints
            /te:named-path-constraint/te:path-in-segment
            /te:label-restrictions/te:label-restriction/te:label-end
            /te:te-label/te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw dwdm-n?    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?    l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw flexi-n?   l0-types:flexi-n
  augment /te:te/te:globals/te:named-path-constraints
            /te:named-path-constraint/te:path-in-segment
            /te:label-restrictions/te:label-restriction/te:label-step
            /te:technology:
    +--:(wdm)
       +--rw (l0-grid-type)?
          +--:(fixed-dwdm)
          |  +--rw wson-dwdm-channel-spacing?    identityref
          +--:(cwdm)
          |  +--rw wson-cwdm-channel-spacing?    identityref
          +--:(flexi-grid)
             x--rw flexi-grid-channel-spacing?   identityref
             +--rw flexi-ncfg?                   identityref
             +--rw flexi-n-step?                 uint8
  augment /te:te/te:globals/te:named-path-constraints
            /te:named-path-constraint/te:path-out-segment
            /te:label-restrictions/te:label-restriction
            /te:label-start/te:te-label/te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw dwdm-n?    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?    l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw flexi-n?   l0-types:flexi-n
  augment /te:te/te:globals/te:named-path-constraints
            /te:named-path-constraint/te:path-out-segment
            /te:label-restrictions/te:label-restriction/te:label-end
            /te:te-label/te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw dwdm-n?    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?    l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw flexi-n?   l0-types:flexi-n
  augment /te:te/te:globals/te:named-path-constraints
            /te:named-path-constraint/te:path-out-segment
            /te:label-restrictions/te:label-restriction/te:label-step
            /te:technology:
    +--:(wdm)
       +--rw (l0-grid-type)?
          +--:(fixed-dwdm)
          |  +--rw wson-dwdm-channel-spacing?    identityref
          +--:(cwdm)
          |  +--rw wson-cwdm-channel-spacing?    identityref
          +--:(flexi-grid)
             x--rw flexi-grid-channel-spacing?   identityref
             +--rw flexi-ncfg?                   identityref
             +--rw flexi-n-step?                 uint8
  augment /te:te/te:tunnels/te:tunnel/te:primary-paths
            /te:primary-path/te:optimizations/te:algorithm/te:metric
            /te:optimization-metric/te:explicit-route-exclude-objects
            /te:route-object-exclude-object/te:type/te:label
            /te:label-hop/te:te-label/te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw (fixed-single-or-super-channel)?
          |     +--:(single)
          |     |  +--rw dwdm-n?               l0-types:dwdm-n
          |     +--:(multi)
          |        +--rw subcarrier-dwdm-n*    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?                     l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw (single-or-super-channel)?
                +--:(single)
                |  +--rw flexi-n?              l0-types:flexi-n
                |  +--rw flexi-m?              l0-types:flexi-m
                x--:(super)
                |  +--rw subcarrier-flexi-n* [flexi-n]
                |     +--rw flexi-n    l0-types:flexi-n
                |     +--rw flexi-m?   l0-types:flexi-m
                +--:(multi)
                   +--rw frequency-slots
                      +--rw frequency-slot* [flexi-n]
                         +--rw flexi-n    l0-types:flexi-n
                         +--rw flexi-m?   l0-types:flexi-m
  augment /te:te/te:tunnels/te:tunnel/te:primary-paths
            /te:primary-path/te:optimizations/te:algorithm/te:metric
            /te:optimization-metric/te:explicit-route-include-objects
            /te:route-object-include-object/te:type/te:label
            /te:label-hop/te:te-label/te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw (fixed-single-or-super-channel)?
          |     +--:(single)
          |     |  +--rw dwdm-n?               l0-types:dwdm-n
          |     +--:(multi)
          |        +--rw subcarrier-dwdm-n*    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?                     l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw (single-or-super-channel)?
                +--:(single)
                |  +--rw flexi-n?              l0-types:flexi-n
                |  +--rw flexi-m?              l0-types:flexi-m
                x--:(super)
                |  +--rw subcarrier-flexi-n* [flexi-n]
                |     +--rw flexi-n    l0-types:flexi-n
                |     +--rw flexi-m?   l0-types:flexi-m
                +--:(multi)
                   +--rw frequency-slots
                      +--rw frequency-slot* [flexi-n]
                         +--rw flexi-n    l0-types:flexi-n
                         +--rw flexi-m?   l0-types:flexi-m
  augment /te:te/te:tunnels/te:tunnel/te:primary-paths
            /te:primary-path/te:explicit-route-objects-always
            /te:route-object-exclude-always/te:type/te:label
            /te:label-hop/te:te-label/te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw (fixed-single-or-super-channel)?
          |     +--:(single)
          |     |  +--rw dwdm-n?               l0-types:dwdm-n
          |     +--:(multi)
          |        +--rw subcarrier-dwdm-n*    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?                     l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw (single-or-super-channel)?
                +--:(single)
                |  +--rw flexi-n?              l0-types:flexi-n
                |  +--rw flexi-m?              l0-types:flexi-m
                x--:(super)
                |  +--rw subcarrier-flexi-n* [flexi-n]
                |     +--rw flexi-n    l0-types:flexi-n
                |     +--rw flexi-m?   l0-types:flexi-m
                +--:(multi)
                   +--rw frequency-slots
                      +--rw frequency-slot* [flexi-n]
                         +--rw flexi-n    l0-types:flexi-n
                         +--rw flexi-m?   l0-types:flexi-m
  augment /te:te/te:tunnels/te:tunnel/te:primary-paths
            /te:primary-path/te:explicit-route-objects-always
            /te:route-object-include-exclude/te:type/te:label
            /te:label-hop/te:te-label/te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw (fixed-single-or-super-channel)?
          |     +--:(single)
          |     |  +--rw dwdm-n?               l0-types:dwdm-n
          |     +--:(multi)
          |        +--rw subcarrier-dwdm-n*    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?                     l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw (single-or-super-channel)?
                +--:(single)
                |  +--rw flexi-n?              l0-types:flexi-n
                |  +--rw flexi-m?              l0-types:flexi-m
                x--:(super)
                |  +--rw subcarrier-flexi-n* [flexi-n]
                |     +--rw flexi-n    l0-types:flexi-n
                |     +--rw flexi-m?   l0-types:flexi-m
                +--:(multi)
                   +--rw frequency-slots
                      +--rw frequency-slot* [flexi-n]
                         +--rw flexi-n    l0-types:flexi-n
                         +--rw flexi-m?   l0-types:flexi-m
  augment /te:te/te:tunnels/te:tunnel/te:primary-paths
            /te:primary-path/te:path-in-segment/te:label-restrictions
            /te:label-restriction/te:label-start/te:te-label
            /te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw dwdm-n?    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?    l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw flexi-n?   l0-types:flexi-n
  augment /te:te/te:tunnels/te:tunnel/te:primary-paths
            /te:primary-path/te:path-in-segment/te:label-restrictions
            /te:label-restriction/te:label-end/te:te-label
            /te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw dwdm-n?    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?    l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw flexi-n?   l0-types:flexi-n
  augment /te:te/te:tunnels/te:tunnel/te:primary-paths
            /te:primary-path/te:path-in-segment/te:label-restrictions
            /te:label-restriction/te:label-step/te:technology:
    +--:(wdm)
       +--rw (l0-grid-type)?
          +--:(fixed-dwdm)
          |  +--rw wson-dwdm-channel-spacing?    identityref
          +--:(cwdm)
          |  +--rw wson-cwdm-channel-spacing?    identityref
          +--:(flexi-grid)
             x--rw flexi-grid-channel-spacing?   identityref
             +--rw flexi-ncfg?                   identityref
             +--rw flexi-n-step?                 uint8
  augment /te:te/te:tunnels/te:tunnel/te:primary-paths
            /te:primary-path/te:path-out-segment
            /te:label-restrictions/te:label-restriction
            /te:label-start/te:te-label/te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw dwdm-n?    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?    l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw flexi-n?   l0-types:flexi-n
  augment /te:te/te:tunnels/te:tunnel/te:primary-paths
            /te:primary-path/te:path-out-segment
            /te:label-restrictions/te:label-restriction/te:label-end
            /te:te-label/te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw dwdm-n?    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?    l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw flexi-n?   l0-types:flexi-n
  augment /te:te/te:tunnels/te:tunnel/te:primary-paths
            /te:primary-path/te:path-out-segment
            /te:label-restrictions/te:label-restriction/te:label-step
            /te:technology:
    +--:(wdm)
       +--rw (l0-grid-type)?
          +--:(fixed-dwdm)
          |  +--rw wson-dwdm-channel-spacing?    identityref
          +--:(cwdm)
          |  +--rw wson-cwdm-channel-spacing?    identityref
          +--:(flexi-grid)
             x--rw flexi-grid-channel-spacing?   identityref
             +--rw flexi-ncfg?                   identityref
             +--rw flexi-n-step?                 uint8
  augment /te:te/te:tunnels/te:tunnel/te:primary-paths
            /te:primary-path/te:computed-paths-properties
            /te:computed-path-properties/te:path-properties
            /te:path-route-objects/te:path-route-object/te:type
            /te:label/te:label-hop/te:te-label/te:technology:
    +--:(wdm)
       +--ro (grid-type)?
          +--:(fixed-dwdm)
          |  +--ro (fixed-single-or-super-channel)?
          |     +--:(single)
          |     |  +--ro dwdm-n?               l0-types:dwdm-n
          |     +--:(multi)
          |        +--ro subcarrier-dwdm-n*    l0-types:dwdm-n
          +--:(cwdm)
          |  +--ro cwdm-n?                     l0-types:cwdm-n
          +--:(flexi-grid)
             +--ro (single-or-super-channel)?
                +--:(single)
                |  +--ro flexi-n?              l0-types:flexi-n
                |  +--ro flexi-m?              l0-types:flexi-m
                x--:(super)
                |  +--ro subcarrier-flexi-n* [flexi-n]
                |     +--ro flexi-n    l0-types:flexi-n
                |     +--ro flexi-m?   l0-types:flexi-m
                +--:(multi)
                   +--ro frequency-slots
                      +--ro frequency-slot* [flexi-n]
                         +--ro flexi-n    l0-types:flexi-n
                         +--ro flexi-m?   l0-types:flexi-m
  augment /te:te/te:tunnels/te:tunnel/te:primary-paths
            /te:primary-path/te:primary-reverse-path/te:optimizations
            /te:algorithm/te:metric/te:optimization-metric
            /te:explicit-route-exclude-objects
            /te:route-object-exclude-object/te:type/te:label
            /te:label-hop/te:te-label/te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw (fixed-single-or-super-channel)?
          |     +--:(single)
          |     |  +--rw dwdm-n?               l0-types:dwdm-n
          |     +--:(multi)
          |        +--rw subcarrier-dwdm-n*    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?                     l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw (single-or-super-channel)?
                +--:(single)
                |  +--rw flexi-n?              l0-types:flexi-n
                |  +--rw flexi-m?              l0-types:flexi-m
                x--:(super)
                |  +--rw subcarrier-flexi-n* [flexi-n]
                |     +--rw flexi-n    l0-types:flexi-n
                |     +--rw flexi-m?   l0-types:flexi-m
                +--:(multi)
                   +--rw frequency-slots
                      +--rw frequency-slot* [flexi-n]
                         +--rw flexi-n    l0-types:flexi-n
                         +--rw flexi-m?   l0-types:flexi-m
  augment /te:te/te:tunnels/te:tunnel/te:primary-paths
            /te:primary-path/te:primary-reverse-path/te:optimizations
            /te:algorithm/te:metric/te:optimization-metric
            /te:explicit-route-include-objects
            /te:route-object-include-object/te:type/te:label
            /te:label-hop/te:te-label/te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw (fixed-single-or-super-channel)?
          |     +--:(single)
          |     |  +--rw dwdm-n?               l0-types:dwdm-n
          |     +--:(multi)
          |        +--rw subcarrier-dwdm-n*    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?                     l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw (single-or-super-channel)?
                +--:(single)
                |  +--rw flexi-n?              l0-types:flexi-n
                |  +--rw flexi-m?              l0-types:flexi-m
                x--:(super)
                |  +--rw subcarrier-flexi-n* [flexi-n]
                |     +--rw flexi-n    l0-types:flexi-n
                |     +--rw flexi-m?   l0-types:flexi-m
                +--:(multi)
                   +--rw frequency-slots
                      +--rw frequency-slot* [flexi-n]
                         +--rw flexi-n    l0-types:flexi-n
                         +--rw flexi-m?   l0-types:flexi-m
  augment /te:te/te:tunnels/te:tunnel/te:primary-paths
            /te:primary-path/te:primary-reverse-path
            /te:explicit-route-objects-always
            /te:route-object-exclude-always/te:type/te:label
            /te:label-hop/te:te-label/te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw (fixed-single-or-super-channel)?
          |     +--:(single)
          |     |  +--rw dwdm-n?               l0-types:dwdm-n
          |     +--:(multi)
          |        +--rw subcarrier-dwdm-n*    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?                     l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw (single-or-super-channel)?
                +--:(single)
                |  +--rw flexi-n?              l0-types:flexi-n
                |  +--rw flexi-m?              l0-types:flexi-m
                x--:(super)
                |  +--rw subcarrier-flexi-n* [flexi-n]
                |     +--rw flexi-n    l0-types:flexi-n
                |     +--rw flexi-m?   l0-types:flexi-m
                +--:(multi)
                   +--rw frequency-slots
                      +--rw frequency-slot* [flexi-n]
                         +--rw flexi-n    l0-types:flexi-n
                         +--rw flexi-m?   l0-types:flexi-m
  augment /te:te/te:tunnels/te:tunnel/te:primary-paths
            /te:primary-path/te:primary-reverse-path
            /te:explicit-route-objects-always
            /te:route-object-include-exclude/te:type/te:label
            /te:label-hop/te:te-label/te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw (fixed-single-or-super-channel)?
          |     +--:(single)
          |     |  +--rw dwdm-n?               l0-types:dwdm-n
          |     +--:(multi)
          |        +--rw subcarrier-dwdm-n*    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?                     l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw (single-or-super-channel)?
                +--:(single)
                |  +--rw flexi-n?              l0-types:flexi-n
                |  +--rw flexi-m?              l0-types:flexi-m
                x--:(super)
                |  +--rw subcarrier-flexi-n* [flexi-n]
                |     +--rw flexi-n    l0-types:flexi-n
                |     +--rw flexi-m?   l0-types:flexi-m
                +--:(multi)
                   +--rw frequency-slots
                      +--rw frequency-slot* [flexi-n]
                         +--rw flexi-n    l0-types:flexi-n
                         +--rw flexi-m?   l0-types:flexi-m
  augment /te:te/te:tunnels/te:tunnel/te:primary-paths
            /te:primary-path/te:primary-reverse-path
            /te:path-in-segment/te:label-restrictions
            /te:label-restriction/te:label-start/te:te-label
            /te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw dwdm-n?    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?    l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw flexi-n?   l0-types:flexi-n
  augment /te:te/te:tunnels/te:tunnel/te:primary-paths
            /te:primary-path/te:primary-reverse-path
            /te:path-in-segment/te:label-restrictions
            /te:label-restriction/te:label-end/te:te-label
            /te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw dwdm-n?    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?    l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw flexi-n?   l0-types:flexi-n
  augment /te:te/te:tunnels/te:tunnel/te:primary-paths
            /te:primary-path/te:primary-reverse-path
            /te:path-in-segment/te:label-restrictions
            /te:label-restriction/te:label-step/te:technology:
    +--:(wdm)
       +--rw (l0-grid-type)?
          +--:(fixed-dwdm)
          |  +--rw wson-dwdm-channel-spacing?    identityref
          +--:(cwdm)
          |  +--rw wson-cwdm-channel-spacing?    identityref
          +--:(flexi-grid)
             x--rw flexi-grid-channel-spacing?   identityref
             +--rw flexi-ncfg?                   identityref
             +--rw flexi-n-step?                 uint8
  augment /te:te/te:tunnels/te:tunnel/te:primary-paths
            /te:primary-path/te:primary-reverse-path
            /te:path-out-segment/te:label-restrictions
            /te:label-restriction/te:label-start/te:te-label
            /te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw dwdm-n?    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?    l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw flexi-n?   l0-types:flexi-n
  augment /te:te/te:tunnels/te:tunnel/te:primary-paths
            /te:primary-path/te:primary-reverse-path
            /te:path-out-segment/te:label-restrictions
            /te:label-restriction/te:label-end/te:te-label
            /te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw dwdm-n?    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?    l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw flexi-n?   l0-types:flexi-n
  augment /te:te/te:tunnels/te:tunnel/te:primary-paths
            /te:primary-path/te:primary-reverse-path
            /te:path-out-segment/te:label-restrictions
            /te:label-restriction/te:label-step/te:technology:
    +--:(wdm)
       +--rw (l0-grid-type)?
          +--:(fixed-dwdm)
          |  +--rw wson-dwdm-channel-spacing?    identityref
          +--:(cwdm)
          |  +--rw wson-cwdm-channel-spacing?    identityref
          +--:(flexi-grid)
             x--rw flexi-grid-channel-spacing?   identityref
             +--rw flexi-ncfg?                   identityref
             +--rw flexi-n-step?                 uint8
  augment /te:te/te:tunnels/te:tunnel/te:primary-paths
            /te:primary-path/te:primary-reverse-path
            /te:computed-paths-properties/te:computed-path-properties
            /te:path-properties/te:path-route-objects
            /te:path-route-object/te:type/te:label/te:label-hop
            /te:te-label/te:technology:
    +--:(wdm)
       +--ro (grid-type)?
          +--:(fixed-dwdm)
          |  +--ro (fixed-single-or-super-channel)?
          |     +--:(single)
          |     |  +--ro dwdm-n?               l0-types:dwdm-n
          |     +--:(multi)
          |        +--ro subcarrier-dwdm-n*    l0-types:dwdm-n
          +--:(cwdm)
          |  +--ro cwdm-n?                     l0-types:cwdm-n
          +--:(flexi-grid)
             +--ro (single-or-super-channel)?
                +--:(single)
                |  +--ro flexi-n?              l0-types:flexi-n
                |  +--ro flexi-m?              l0-types:flexi-m
                x--:(super)
                |  +--ro subcarrier-flexi-n* [flexi-n]
                |     +--ro flexi-n    l0-types:flexi-n
                |     +--ro flexi-m?   l0-types:flexi-m
                +--:(multi)
                   +--ro frequency-slots
                      +--ro frequency-slot* [flexi-n]
                         +--ro flexi-n    l0-types:flexi-n
                         +--ro flexi-m?   l0-types:flexi-m
  augment /te:te/te:tunnels/te:tunnel/te:secondary-paths
            /te:secondary-path/te:optimizations/te:algorithm
            /te:metric/te:optimization-metric
            /te:explicit-route-exclude-objects
            /te:route-object-exclude-object/te:type/te:label
            /te:label-hop/te:te-label/te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw (fixed-single-or-super-channel)?
          |     +--:(single)
          |     |  +--rw dwdm-n?               l0-types:dwdm-n
          |     +--:(multi)
          |        +--rw subcarrier-dwdm-n*    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?                     l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw (single-or-super-channel)?
                +--:(single)
                |  +--rw flexi-n?              l0-types:flexi-n
                |  +--rw flexi-m?              l0-types:flexi-m
                x--:(super)
                |  +--rw subcarrier-flexi-n* [flexi-n]
                |     +--rw flexi-n    l0-types:flexi-n
                |     +--rw flexi-m?   l0-types:flexi-m
                +--:(multi)
                   +--rw frequency-slots
                      +--rw frequency-slot* [flexi-n]
                         +--rw flexi-n    l0-types:flexi-n
                         +--rw flexi-m?   l0-types:flexi-m
  augment /te:te/te:tunnels/te:tunnel/te:secondary-paths
            /te:secondary-path/te:optimizations/te:algorithm
            /te:metric/te:optimization-metric
            /te:explicit-route-include-objects
            /te:route-object-include-object/te:type/te:label
            /te:label-hop/te:te-label/te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw (fixed-single-or-super-channel)?
          |     +--:(single)
          |     |  +--rw dwdm-n?               l0-types:dwdm-n
          |     +--:(multi)
          |        +--rw subcarrier-dwdm-n*    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?                     l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw (single-or-super-channel)?
                +--:(single)
                |  +--rw flexi-n?              l0-types:flexi-n
                |  +--rw flexi-m?              l0-types:flexi-m
                x--:(super)
                |  +--rw subcarrier-flexi-n* [flexi-n]
                |     +--rw flexi-n    l0-types:flexi-n
                |     +--rw flexi-m?   l0-types:flexi-m
                +--:(multi)
                   +--rw frequency-slots
                      +--rw frequency-slot* [flexi-n]
                         +--rw flexi-n    l0-types:flexi-n
                         +--rw flexi-m?   l0-types:flexi-m
  augment /te:te/te:tunnels/te:tunnel/te:secondary-paths
            /te:secondary-path/te:explicit-route-objects-always
            /te:route-object-exclude-always/te:type/te:label
            /te:label-hop/te:te-label/te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw (fixed-single-or-super-channel)?
          |     +--:(single)
          |     |  +--rw dwdm-n?               l0-types:dwdm-n
          |     +--:(multi)
          |        +--rw subcarrier-dwdm-n*    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?                     l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw (single-or-super-channel)?
                +--:(single)
                |  +--rw flexi-n?              l0-types:flexi-n
                |  +--rw flexi-m?              l0-types:flexi-m
                x--:(super)
                |  +--rw subcarrier-flexi-n* [flexi-n]
                |     +--rw flexi-n    l0-types:flexi-n
                |     +--rw flexi-m?   l0-types:flexi-m
                +--:(multi)
                   +--rw frequency-slots
                      +--rw frequency-slot* [flexi-n]
                         +--rw flexi-n    l0-types:flexi-n
                         +--rw flexi-m?   l0-types:flexi-m
  augment /te:te/te:tunnels/te:tunnel/te:secondary-paths
            /te:secondary-path/te:explicit-route-objects-always
            /te:route-object-include-exclude/te:type/te:label
            /te:label-hop/te:te-label/te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw (fixed-single-or-super-channel)?
          |     +--:(single)
          |     |  +--rw dwdm-n?               l0-types:dwdm-n
          |     +--:(multi)
          |        +--rw subcarrier-dwdm-n*    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?                     l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw (single-or-super-channel)?
                +--:(single)
                |  +--rw flexi-n?              l0-types:flexi-n
                |  +--rw flexi-m?              l0-types:flexi-m
                x--:(super)
                |  +--rw subcarrier-flexi-n* [flexi-n]
                |     +--rw flexi-n    l0-types:flexi-n
                |     +--rw flexi-m?   l0-types:flexi-m
                +--:(multi)
                   +--rw frequency-slots
                      +--rw frequency-slot* [flexi-n]
                         +--rw flexi-n    l0-types:flexi-n
                         +--rw flexi-m?   l0-types:flexi-m
  augment /te:te/te:tunnels/te:tunnel/te:secondary-paths
            /te:secondary-path/te:path-in-segment
            /te:label-restrictions/te:label-restriction
            /te:label-start/te:te-label/te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw dwdm-n?    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?    l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw flexi-n?   l0-types:flexi-n
  augment /te:te/te:tunnels/te:tunnel/te:secondary-paths
            /te:secondary-path/te:path-in-segment
            /te:label-restrictions/te:label-restriction/te:label-end
            /te:te-label/te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw dwdm-n?    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?    l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw flexi-n?   l0-types:flexi-n
  augment /te:te/te:tunnels/te:tunnel/te:secondary-paths
            /te:secondary-path/te:path-in-segment
            /te:label-restrictions/te:label-restriction/te:label-step
            /te:technology:
    +--:(wdm)
       +--rw (l0-grid-type)?
          +--:(fixed-dwdm)
          |  +--rw wson-dwdm-channel-spacing?    identityref
          +--:(cwdm)
          |  +--rw wson-cwdm-channel-spacing?    identityref
          +--:(flexi-grid)
             x--rw flexi-grid-channel-spacing?   identityref
             +--rw flexi-ncfg?                   identityref
             +--rw flexi-n-step?                 uint8
  augment /te:te/te:tunnels/te:tunnel/te:secondary-paths
            /te:secondary-path/te:path-out-segment
            /te:label-restrictions/te:label-restriction
            /te:label-start/te:te-label/te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw dwdm-n?    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?    l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw flexi-n?   l0-types:flexi-n
  augment /te:te/te:tunnels/te:tunnel/te:secondary-paths
            /te:secondary-path/te:path-out-segment
            /te:label-restrictions/te:label-restriction/te:label-end
            /te:te-label/te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw dwdm-n?    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?    l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw flexi-n?   l0-types:flexi-n
  augment /te:te/te:tunnels/te:tunnel/te:secondary-paths
            /te:secondary-path/te:path-out-segment
            /te:label-restrictions/te:label-restriction/te:label-step
            /te:technology:
    +--:(wdm)
       +--rw (l0-grid-type)?
          +--:(fixed-dwdm)
          |  +--rw wson-dwdm-channel-spacing?    identityref
          +--:(cwdm)
          |  +--rw wson-cwdm-channel-spacing?    identityref
          +--:(flexi-grid)
             x--rw flexi-grid-channel-spacing?   identityref
             +--rw flexi-ncfg?                   identityref
             +--rw flexi-n-step?                 uint8
  augment /te:te/te:tunnels/te:tunnel/te:secondary-paths
            /te:secondary-path/te:computed-paths-properties
            /te:computed-path-properties/te:path-properties
            /te:path-route-objects/te:path-route-object/te:type
            /te:label/te:label-hop/te:te-label/te:technology:
    +--:(wdm)
       +--ro (grid-type)?
          +--:(fixed-dwdm)
          |  +--ro (fixed-single-or-super-channel)?
          |     +--:(single)
          |     |  +--ro dwdm-n?               l0-types:dwdm-n
          |     +--:(multi)
          |        +--ro subcarrier-dwdm-n*    l0-types:dwdm-n
          +--:(cwdm)
          |  +--ro cwdm-n?                     l0-types:cwdm-n
          +--:(flexi-grid)
             +--ro (single-or-super-channel)?
                +--:(single)
                |  +--ro flexi-n?              l0-types:flexi-n
                |  +--ro flexi-m?              l0-types:flexi-m
                x--:(super)
                |  +--ro subcarrier-flexi-n* [flexi-n]
                |     +--ro flexi-n    l0-types:flexi-n
                |     +--ro flexi-m?   l0-types:flexi-m
                +--:(multi)
                   +--ro frequency-slots
                      +--ro frequency-slot* [flexi-n]
                         +--ro flexi-n    l0-types:flexi-n
                         +--ro flexi-m?   l0-types:flexi-m
  augment /te:te/te:tunnels/te:tunnel/te:secondary-reverse-paths
            /te:secondary-reverse-path/te:optimizations/te:algorithm
            /te:metric/te:optimization-metric
            /te:explicit-route-exclude-objects
            /te:route-object-exclude-object/te:type/te:label
            /te:label-hop/te:te-label/te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw (fixed-single-or-super-channel)?
          |     +--:(single)
          |     |  +--rw dwdm-n?               l0-types:dwdm-n
          |     +--:(multi)
          |        +--rw subcarrier-dwdm-n*    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?                     l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw (single-or-super-channel)?
                +--:(single)
                |  +--rw flexi-n?              l0-types:flexi-n
                |  +--rw flexi-m?              l0-types:flexi-m
                x--:(super)
                |  +--rw subcarrier-flexi-n* [flexi-n]
                |     +--rw flexi-n    l0-types:flexi-n
                |     +--rw flexi-m?   l0-types:flexi-m
                +--:(multi)
                   +--rw frequency-slots
                      +--rw frequency-slot* [flexi-n]
                         +--rw flexi-n    l0-types:flexi-n
                         +--rw flexi-m?   l0-types:flexi-m
  augment /te:te/te:tunnels/te:tunnel/te:secondary-reverse-paths
            /te:secondary-reverse-path/te:optimizations/te:algorithm
            /te:metric/te:optimization-metric
            /te:explicit-route-include-objects
            /te:route-object-include-object/te:type/te:label
            /te:label-hop/te:te-label/te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw (fixed-single-or-super-channel)?
          |     +--:(single)
          |     |  +--rw dwdm-n?               l0-types:dwdm-n
          |     +--:(multi)
          |        +--rw subcarrier-dwdm-n*    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?                     l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw (single-or-super-channel)?
                +--:(single)
                |  +--rw flexi-n?              l0-types:flexi-n
                |  +--rw flexi-m?              l0-types:flexi-m
                x--:(super)
                |  +--rw subcarrier-flexi-n* [flexi-n]
                |     +--rw flexi-n    l0-types:flexi-n
                |     +--rw flexi-m?   l0-types:flexi-m
                +--:(multi)
                   +--rw frequency-slots
                      +--rw frequency-slot* [flexi-n]
                         +--rw flexi-n    l0-types:flexi-n
                         +--rw flexi-m?   l0-types:flexi-m
  augment /te:te/te:tunnels/te:tunnel/te:secondary-reverse-paths
            /te:secondary-reverse-path
            /te:explicit-route-objects-always
            /te:route-object-exclude-always/te:type/te:label
            /te:label-hop/te:te-label/te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw (fixed-single-or-super-channel)?
          |     +--:(single)
          |     |  +--rw dwdm-n?               l0-types:dwdm-n
          |     +--:(multi)
          |        +--rw subcarrier-dwdm-n*    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?                     l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw (single-or-super-channel)?
                +--:(single)
                |  +--rw flexi-n?              l0-types:flexi-n
                |  +--rw flexi-m?              l0-types:flexi-m
                x--:(super)
                |  +--rw subcarrier-flexi-n* [flexi-n]
                |     +--rw flexi-n    l0-types:flexi-n
                |     +--rw flexi-m?   l0-types:flexi-m
                +--:(multi)
                   +--rw frequency-slots
                      +--rw frequency-slot* [flexi-n]
                         +--rw flexi-n    l0-types:flexi-n
                         +--rw flexi-m?   l0-types:flexi-m
  augment /te:te/te:tunnels/te:tunnel/te:secondary-reverse-paths
            /te:secondary-reverse-path
            /te:explicit-route-objects-always
            /te:route-object-include-exclude/te:type/te:label
            /te:label-hop/te:te-label/te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw (fixed-single-or-super-channel)?
          |     +--:(single)
          |     |  +--rw dwdm-n?               l0-types:dwdm-n
          |     +--:(multi)
          |        +--rw subcarrier-dwdm-n*    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?                     l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw (single-or-super-channel)?
                +--:(single)
                |  +--rw flexi-n?              l0-types:flexi-n
                |  +--rw flexi-m?              l0-types:flexi-m
                x--:(super)
                |  +--rw subcarrier-flexi-n* [flexi-n]
                |     +--rw flexi-n    l0-types:flexi-n
                |     +--rw flexi-m?   l0-types:flexi-m
                +--:(multi)
                   +--rw frequency-slots
                      +--rw frequency-slot* [flexi-n]
                         +--rw flexi-n    l0-types:flexi-n
                         +--rw flexi-m?   l0-types:flexi-m
  augment /te:te/te:tunnels/te:tunnel/te:secondary-reverse-paths
            /te:secondary-reverse-path/te:path-in-segment
            /te:label-restrictions/te:label-restriction
            /te:label-start/te:te-label/te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw dwdm-n?    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?    l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw flexi-n?   l0-types:flexi-n
  augment /te:te/te:tunnels/te:tunnel/te:secondary-reverse-paths
            /te:secondary-reverse-path/te:path-in-segment
            /te:label-restrictions/te:label-restriction/te:label-end
            /te:te-label/te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw dwdm-n?    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?    l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw flexi-n?   l0-types:flexi-n
  augment /te:te/te:tunnels/te:tunnel/te:secondary-reverse-paths
            /te:secondary-reverse-path/te:path-in-segment
            /te:label-restrictions/te:label-restriction/te:label-step
            /te:technology:
    +--:(wdm)
       +--rw (l0-grid-type)?
          +--:(fixed-dwdm)
          |  +--rw wson-dwdm-channel-spacing?    identityref
          +--:(cwdm)
          |  +--rw wson-cwdm-channel-spacing?    identityref
          +--:(flexi-grid)
             x--rw flexi-grid-channel-spacing?   identityref
             +--rw flexi-ncfg?                   identityref
             +--rw flexi-n-step?                 uint8
  augment /te:te/te:tunnels/te:tunnel/te:secondary-reverse-paths
            /te:secondary-reverse-path/te:path-out-segment
            /te:label-restrictions/te:label-restriction
            /te:label-start/te:te-label/te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw dwdm-n?    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?    l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw flexi-n?   l0-types:flexi-n
  augment /te:te/te:tunnels/te:tunnel/te:secondary-reverse-paths
            /te:secondary-reverse-path/te:path-out-segment
            /te:label-restrictions/te:label-restriction/te:label-end
            /te:te-label/te:technology:
    +--:(wdm)
       +--rw (grid-type)?
          +--:(fixed-dwdm)
          |  +--rw dwdm-n?    l0-types:dwdm-n
          +--:(cwdm)
          |  +--rw cwdm-n?    l0-types:cwdm-n
          +--:(flexi-grid)
             +--rw flexi-n?   l0-types:flexi-n
  augment /te:te/te:tunnels/te:tunnel/te:secondary-reverse-paths
            /te:secondary-reverse-path/te:path-out-segment
            /te:label-restrictions/te:label-restriction/te:label-step
            /te:technology:
    +--:(wdm)
       +--rw (l0-grid-type)?
          +--:(fixed-dwdm)
          |  +--rw wson-dwdm-channel-spacing?    identityref
          +--:(cwdm)
          |  +--rw wson-cwdm-channel-spacing?    identityref
          +--:(flexi-grid)
             x--rw flexi-grid-channel-spacing?   identityref
             +--rw flexi-ncfg?                   identityref
             +--rw flexi-n-step?                 uint8
  augment /te:te/te:tunnels/te:tunnel/te:secondary-reverse-paths
            /te:secondary-reverse-path/te:computed-paths-properties
            /te:computed-path-properties/te:path-properties
            /te:path-route-objects/te:path-route-object/te:type
            /te:label/te:label-hop/te:te-label/te:technology:
    +--:(wdm)
       +--ro (grid-type)?
          +--:(fixed-dwdm)
          |  +--ro (fixed-single-or-super-channel)?
          |     +--:(single)
          |     |  +--ro dwdm-n?               l0-types:dwdm-n
          |     +--:(multi)
          |        +--ro subcarrier-dwdm-n*    l0-types:dwdm-n
          +--:(cwdm)
          |  +--ro cwdm-n?                     l0-types:cwdm-n
          +--:(flexi-grid)
             +--ro (single-or-super-channel)?
                +--:(single)
                |  +--ro flexi-n?              l0-types:flexi-n
                |  +--ro flexi-m?              l0-types:flexi-m
                x--:(super)
                |  +--ro subcarrier-flexi-n* [flexi-n]
                |     +--ro flexi-n    l0-types:flexi-n
                |     +--ro flexi-m?   l0-types:flexi-m
                +--:(multi)
                   +--ro frequency-slots
                      +--ro frequency-slot* [flexi-n]
                         +--ro flexi-n    l0-types:flexi-n
                         +--ro flexi-m?   l0-types:flexi-m
  augment /te:te/te:lsps/te:lsp/te:lsp-actual-route-information
            /te:lsp-actual-route-information/te:type/te:label
            /te:label-hop/te:te-label/te:technology:
    +--:(wdm)
       +--ro (grid-type)?
          +--:(fixed-dwdm)
          |  +--ro (fixed-single-or-super-channel)?
          |     +--:(single)
          |     |  +--ro dwdm-n?               l0-types:dwdm-n
          |     +--:(multi)
          |        +--ro subcarrier-dwdm-n*    l0-types:dwdm-n
          +--:(cwdm)
          |  +--ro cwdm-n?                     l0-types:cwdm-n
          +--:(flexi-grid)
             +--ro (single-or-super-channel)?
                +--:(single)
                |  +--ro flexi-n?              l0-types:flexi-n
                |  +--ro flexi-m?              l0-types:flexi-m
                x--:(super)
                |  +--ro subcarrier-flexi-n* [flexi-n]
                |     +--ro flexi-n    l0-types:flexi-n
                |     +--ro flexi-m?   l0-types:flexi-m
                +--:(multi)
                   +--ro frequency-slots
                      +--ro frequency-slot* [flexi-n]
                         +--ro flexi-n    l0-types:flexi-n
                         +--ro flexi-m?   l0-types:flexi-m

5.2. YANG Code

<CODE BEGINS> file "ietf-wdm-tunnel@2023-10-22.yang"

module ietf-wdm-tunnel {
  yang-version 1.1;
  namespace
    "urn:ietf:params:xml:ns:yang:ietf-wdm-tunnel";
  prefix "wdm-tnl";

  import ietf-te {
    prefix "te";
    revision-date "2023-06-16";
    reference
      "I-D.ietf-teas-yang-te-34: A YANG Data Model for Traffic
      Engineering Tunnels, Label Switched Paths and Interfaces.";
  }

  import 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:   Jorge E. Lopez de Vergara
               <jorge.lopez_vergara@uam.es>

     Editor:   Daniel Perdices
               <daniel.perdices@naudit.es>

     Editor:   Victor Lopez
               <victor.lopez@nokia.com>

     Editor:   Italo Busi
               <italo.busi@nokia.com>

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

  description
    "This module defines a YANG data model for configuring
     and managing Wavelength-Division Multiplexing (WDM) switched
     optical tunnels.

    The model fully conforms to the Network Management
    Datastore Architecture (NMDA).

    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 XXXX; see
    the RFC itself for full legal notices.";

  revision "2023-10-22" {
    description
      "Updated revision with combined WSON and Flexi-grid tunnel
       YANG model";

    reference
      "RFC XXXX: YANG data model for WDM tunnels";
    // RFC Ed.: replace XXXX with actual RFC number, update date
    // information and remove this note
  }

  /*
   * Identities
   */
  identity lower-first-wavelength-assignment {
    base l0-types:wavelength-assignment;
    description
      "Assign first available wavelength starting from the
       lowest frequency towards the highest frequency in
       the allowable frequency range.";
  }

  identity upper-first-wavelength-assignment {
    base l0-types:wavelength-assignment;
    description
      "Assign first available wavelength starting from the
       highest frequency towards the lowest frequency in
       the allowable frequency range.";
  }

  /*
   * Groupings
   */
  grouping tx-tune-constraints {
    description
      "This grouping defines the transmitter's allowed tuning
       frequency range.";

    container tx-tune-constraints {
      description
        "Transmitter's allowed tuning frequency range.";

      uses l0-types:transmitter-tuning-range;
    }
  }

  grouping transceiver-constraints-grp {
    description
      "This grouping defines constraints for transceiver
       configurations";

    leaf-list operational-modes {
      type string {
        length "1..255";
      }
      description
        "List of operational mode ids of the transceiver.";
    }

    uses tx-tune-constraints;
  }

  grouping path-transceiver-config-grp {
    description
      "This grouping defines explicit transceiver configurations
       on an end-to-end path.";

    leaf transponder-id {
      type uint32;
      description "transponder identifier";
    }

    list transceivers {
      key "lane-id";
      description
        "List of transceivers for all lanes.";

      leaf lane-id {
        type uint8;
        must '. >= 1' {
          error-message
            "Lane identifier must be greater than or equal to 1.";
        }
        description
          "Lane identifier starting from 1.";
      }
      leaf transceiver-id {
        type uint32;
        description
        "transceiver identifier";
      }
    }

    uses transceiver-constraints-grp;
  }

  grouping path-transceiver-grp {
    description
      "This grouping defines group of transceivers on a node
       functioning as starting, terminating transceivers, or
       regenerators.";

    container path-in-transceiver {
      description
        "Constraints for incoming direction transceiver
         configurations";

      uses path-transceiver-config-grp;
    }

    container path-out-transceiver {
      description
        "Constraints for outgoing direction transceiver
         configurations";

      uses path-transceiver-config-grp;
    }
  }

  grouping global-transceiver-constraint {
    description
      "This grouping defines the constraints for transceiver
       configurations.";

    container transceiver-constraint {
      description
        "Constraints for transceiver configurations";

      uses transceiver-constraints-grp;
    }
  }

  grouping wdm-constraint {
    description
      "Grouping for WDM tunnel constraints";

    container wdm-constraint {
      description
        "WDM tunnel constraints.";

      uses global-transceiver-constraint;
      uses l0-types:l0-path-constraints;

      leaf use-regen {
        type boolean;
        default false;
        description
          "Indicate whether or not regenerators (e.g. 3R) should be
           considered. When this parameter is set to true, the
           tunnel path may include a regen when the path is not
           feasible for direct optical reach.";
      }

      leaf wavelength-conversion {
        when '../use-regen = "true"' {
          description
            "Regenerator must be enabled for wavelength conversion
             to be considered.";
        }
        type boolean;
        default false;
        description
          "Indicate whether or not wavelength conversion is allowed
           along the tunnel path. Applicable only when 3R
           regeneration is enabled.";
      }

      uses l0-types:l0-tunnel-attributes;

      leaf guard-band-size {
        type l0-types:frequency-thz;
        description
          "Guard band size in THz.";
      }

      leaf matching-fwd-rev-wavelength {
        type boolean;
        default true;
        description
          "Indicate whether or not the assigned channels for
           forward and reverse wavelength path must be the same.";
      }

      leaf allow-retuning {
        type boolean;
        default false;
        description
          "Indicate whether or not re-tuning is allowed when one or
           more paths of a WDM tunnel is being restored. Typically,
           wavelength retuning is not preferred for wavelength
           planning considerations.";
      }
      leaf delta-power {
        type l0-types:gain-in-db-or-null;
        units "dB";
        description
          "Delta power in dB indicating the per-channel power
           deviation from the nominal power per channel at the
           output of an OMS.";
      }
    }
  }

  grouping wdm-path-state {
    description
      "Grouping for WDM path state.";

    container wdm-path-state {
      config false;
      description
        "WDM path state.";

      leaf gsnr {
        type l0-types:snr;
        description
          "Actual received GSNR for the WDM path.";
      }
    }
  }

  /*
   * Data nodes
   */

  /*
   * Global constraints for WDM tunnel
   */
  augment "/te:te/te:tunnels/te:tunnel" {
    description
      "Augment with additional parameters required for WDM
       tunnel configurations.";
    uses wdm-constraint;
  }

  /*
   * Transceiver constraints for primary path
   * Applicable to starting, terminating and regenerator
   * transceivers.
   */
  augment "/te:te/te:tunnels/te:tunnel/te:primary-paths/"
        + "te:primary-path/te:explicit-route-objects-always/"
        + "te:route-object-exclude-always/te:type/"
        + "te:numbered-node-hop/te:numbered-node-hop" {
    description
      "Augment TE primary path with transceiver configurations.";

    uses path-transceiver-grp;
  }

  /*
   * Transceiver constraints for primary reverse path
   * Applicable to starting, terminating and regenerator
   * transceivers.
   */
  augment "/te:te/te:tunnels/te:tunnel/te:primary-paths/"
        + "te:primary-path/te:primary-reverse-path/"
        + "te:explicit-route-objects-always/"
        + "te:route-object-exclude-always/te:type/"
        + "te:numbered-node-hop/te:numbered-node-hop" {
    description
      "Augment TE primary reverse path with transceiver
       configurations.";

    uses path-transceiver-grp;
  }

  /*
   * Computed path properties for primary path.
   */
  augment "/te:te/te:tunnels/te:tunnel/te:primary-paths/"
        + "te:primary-path/te:computed-paths-properties/"
        + "te:computed-path-properties/te:path-properties" {
    description
      "Augment TE computed primary path with WDM properties.";

    uses l0-types:l0-path-properties;
  }

  /*
   * Computed path properties for primary reverse path.
   */
  augment "/te:te/te:tunnels/te:tunnel/te:primary-paths/"
        + "te:primary-path/te:primary-reverse-path/"
        + "te:computed-paths-properties/"
        + "te:computed-path-properties/te:path-properties" {
    description
      "Augment TE computed primary reverse path with WDM
       properties.";

    uses l0-types:l0-path-properties;
  }

  /*
   * Transceiver constraints for secondary path
   * Applicable to starting, terminating and regenerator
   * transceivers.
   */
  augment "/te:te/te:tunnels/te:tunnel/te:secondary-paths/"
        + "te:secondary-path/te:explicit-route-objects-always/"
        + "te:route-object-exclude-always/te:type/"
        + "te:numbered-node-hop/te:numbered-node-hop" {
    description
      "Augment TE secondary path with transceiver configurations.";

    uses path-transceiver-grp;
  }

  /*
   * Transceiver constraints for secondary reverse path
   * Applicable to starting, terminating and regenerator
   * transceivers.
   */
  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:secondary-reverse-paths/"
        + "te:secondary-reverse-path/"
        + "te:explicit-route-objects-always/"
        + "te:route-object-exclude-always/te:type/"
        + "te:numbered-node-hop/te:numbered-node-hop" {
    description
      "Augment TE secondary reverse path with transceiver
       configurations.";

    uses path-transceiver-grp;
  }

  /*
   * Computed path properties for secondary path.
   */
  augment "/te:te/te:tunnels/te:tunnel/te:secondary-paths/"
        + "te:secondary-path/te:computed-paths-properties/"
        + "te:computed-path-properties/te:path-properties" {
    description
      "Augment TE computed secondary path with WDM properties.";

    uses l0-types:l0-path-properties;
  }

  /*
   * Computed path properties for secondary reverse path.
   */
  augment "/te:te/te:tunnels/te:tunnel/te:secondary-reverse-paths/"
        + "te:secondary-reverse-path/te:computed-paths-properties/"
        + "te:computed-path-properties/te:path-properties" {
    description
      "Augment TE computed secondary reverse path with WDM
       properties.";

    uses l0-types:l0-path-properties;
  }

  /*
   * WDM path state
   */
  augment "/te:te/te:lsps/te:lsp/"
        + "te:lsp-actual-route-information" {
    description
      "Augment TE LSP to with WDM path state.";

    uses wdm-path-state;
  }

  /*
   * Augment TE label range information
   */

  augment "/te:te/te:globals/te:named-path-constraints/"
        + "te:named-path-constraint/te:path-in-segment/"
        + "te:label-restrictions/te:label-restriction" {
    description
      "Augment TE label range information for the ingress segment
      of the named path constraint.";
    uses l0-types:wdm-label-range-info;
  }

  augment "/te:te/te:globals/te:named-path-constraints/"
        + "te:named-path-constraint/te:path-out-segment/"
        + "te:label-restrictions/"
        + "te:label-restriction" {
    description
      "Augment TE label range information for the egress segment
      of the named path constraint.";
    uses l0-types:wdm-label-range-info;
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:primary-paths/te:primary-path/"
        + "te:path-in-segment/te:label-restrictions/"
        + "te:label-restriction" {
    description
      "Augment TE label range information for the ingress segment
      of the primay path.";
    uses l0-types:wdm-label-range-info;
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:primary-paths/te:primary-path/"
        + "te:path-out-segment/te:label-restrictions/"
        + "te:label-restriction" {
    description
      "Augment TE label range information for the egress segment
      of the primay path.";
    uses l0-types:wdm-label-range-info;
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:primary-paths/te:primary-path/"
        + "te:primary-reverse-path/"
        + "te:path-in-segment/te:label-restrictions/"
        + "te:label-restriction" {
    description
      "Augment TE label range information for the ingress segment
      of the primay reverse path.";
    uses l0-types:wdm-label-range-info;
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:primary-paths/te:primary-path/"
        + "te:primary-reverse-path/"
        + "te:path-out-segment/te:label-restrictions/"
        + "te:label-restriction" {
    description
      "Augment TE label range information for the egress segment
      of the primay reverse path.";
    uses l0-types:wdm-label-range-info;
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:secondary-paths/te:secondary-path/"
        + "te:path-in-segment/te:label-restrictions/"
        + "te:label-restriction" {
    description
      "Augment TE label range information for the ingress segment
      of the secondary path.";
    uses l0-types:wdm-label-range-info;
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:secondary-paths/te:secondary-path/"
        + "te:path-out-segment/te:label-restrictions/"
        + "te:label-restriction" {
    description
      "Augment TE label range information for the egress segment
      of the secondary path.";
    uses l0-types:wdm-label-range-info;
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:secondary-reverse-paths/te:secondary-reverse-path/"
        + "te:path-in-segment/te:label-restrictions/"
        + "te:label-restriction" {
    description
      "Augment TE label range information for the ingress segment
      of the secondary reverse path.";
    uses l0-types:wdm-label-range-info;
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:secondary-reverse-paths/te:secondary-reverse-path/"
        + "te:path-out-segment/te:label-restrictions/"
        + "te:label-restriction" {
    description
      "Augment TE label range information for the egress segment
      of the secondary reverse path.";
    uses l0-types:wdm-label-range-info;
  }

  /*
   * Augment TE label.
   */
  augment "/te:te/te:globals/te:named-path-constraints/"
        + "te:named-path-constraint/"
        + "te:explicit-route-objects-always/"
        + "te:route-object-exclude-always/te:type/te:label/"
        + "te:label-hop/te:te-label/te:technology" {
    description
      "Augment TE label hop for the explicit route objects always
      excluded by the path computation with the named path
      constraint.";
    case wdm {
      uses l0-types:wdm-label-hop;
    }
  }

  augment "/te:te/te:globals/te:named-path-constraints/"
        + "te:named-path-constraint/"
        + "te:explicit-route-objects-always/"
        + "te:route-object-include-exclude/te:type/te:label/"
        + "te:label-hop/te:te-label/te:technology" {
    description
      "Augment TE label hop for the explicit route objects included
      or excluded by the path computation with the named path
      constraint.";
    case wdm {
      uses l0-types:wdm-label-hop;
    }
  }
  augment "/te:te/te:globals/te:named-path-constraints/"
        + "te:named-path-constraint/te:path-in-segment/"
        + "te:label-restrictions/"
        + "te:label-restriction/te:label-start/"
        + "te:te-label/te:technology" {
    description
      "Augment TE label range start for the ingress segment
      of the named path constraint.";
    case wdm {
      uses l0-types:wdm-label-start-end;
    }
  }

  augment "/te:te/te:globals/te:named-path-constraints/"
        + "te:named-path-constraint/te:path-in-segment/"
        + "te:label-restrictions/"
        + "te:label-restriction/te:label-end/"
        + "te:te-label/te:technology" {
    description
      "Augment TE label range end for the ingress segment
      of the named path constraint.";
    case wdm {
      uses l0-types:wdm-label-start-end;
    }
  }

  augment "/te:te/te:globals/te:named-path-constraints/"
        + "te:named-path-constraint/te:path-in-segment/"
        + "te:label-restrictions/te:label-restriction/"
        + "te:label-step/te:technology" {
    description
      "Augment TE label range step for the ingress segment
      of the named path constraint.";
    case wdm {
      uses l0-types:wdm-label-step;
    }
  }

  augment "/te:te/te:globals/te:named-path-constraints/"
        + "te:named-path-constraint/te:path-out-segment/"
        + "te:label-restrictions/"
        + "te:label-restriction/te:label-start/"
        + "te:te-label/te:technology" {
    description
      "Augment TE label range start for the egress segment
      of the named path constraint.";
    case wdm {
      uses l0-types:wdm-label-start-end;
    }
  }

  augment "/te:te/te:globals/te:named-path-constraints/"
        + "te:named-path-constraint/te:path-out-segment/"
        + "te:label-restrictions/"
        + "te:label-restriction/te:label-end/"
        + "te:te-label/te:technology" {
    description
      "Augment TE label range end for the egress segment
      of the named path constraint.";
    case wdm {
      uses l0-types:wdm-label-start-end;
    }
  }

  augment "/te:te/te:globals/te:named-path-constraints/"
        + "te:named-path-constraint/te:path-out-segment/"
        + "te:label-restrictions/te:label-restriction/"
        + "te:label-step/te:technology" {
    description
      "Augment TE label range step for the egress segment
      of the named path constraint.";
    case wdm {
      uses l0-types:wdm-label-step;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:primary-paths/te:primary-path/"
        + "te:optimizations/te:algorithm/te:metric/"
        + "te:optimization-metric/te:explicit-route-exclude-objects/"
        + "te:route-object-exclude-object/te:type/te:label/"
        + "te:label-hop/te:te-label/te:technology" {
    description
      "Augment TE label hop for the optimization of the explicit
      route objects excluded by the path computation of the primary
      path.";
    case wdm {
      uses l0-types:wdm-label-hop;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:primary-paths/te:primary-path/"
        + "te:optimizations/te:algorithm/te:metric/"
        + "te:optimization-metric/te:explicit-route-include-objects/"
        + "te:route-object-include-object/te:type/te:label/"
        + "te:label-hop/te:te-label/te:technology" {
    description
      "Augment TE label hop for the optimization of the explicit
      route objects included by the path computation of the primary
      path.";
    case wdm {
      uses l0-types:wdm-label-hop;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:primary-paths/te:primary-path/"
        + "te:explicit-route-objects-always/"
        + "te:route-object-exclude-always/te:type/te:label/"
        + "te:label-hop/te:te-label/te:technology" {
    description
      "Augment TE label hop for the explicit route objects always
      excluded by the path computation of the primary path.";
    case wdm {
      uses l0-types:wdm-label-hop;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:primary-paths/te:primary-path/"
        + "te:explicit-route-objects-always/"
        + "te:route-object-include-exclude/te:type/te:label/"
        + "te:label-hop/te:te-label/te:technology" {
    description
      "Augment TE label hop for the explicit route objects included
      or excluded by the path computation of the primary path.";
    case wdm {
      uses l0-types:wdm-label-hop;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:primary-paths/te:primary-path/"
        + "te:path-in-segment/te:label-restrictions/"
        + "te:label-restriction/te:label-start/"
        + "te:te-label/te:technology" {
    description
      "Augment TE label range start for the ingress segment
      of the primay path.";
    case wdm {
      uses l0-types:wdm-label-start-end;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:primary-paths/te:primary-path/"
        + "te:path-in-segment/te:label-restrictions/"
        + "te:label-restriction/te:label-end/"
        + "te:te-label/te:technology" {
    description
      "Augment TE label range end for the ingress segment
      of the primay path.";
    case wdm {
      uses l0-types:wdm-label-start-end;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:primary-paths/te:primary-path/"
        + "te:path-in-segment/te:label-restrictions/"
        + "te:label-restriction/te:label-step/te:technology" {
    description
      "Augment TE label range step for the ingress segment
      of the primay path.";
    case wdm {
      uses l0-types:wdm-label-step;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:primary-paths/te:primary-path/"
        + "te:path-out-segment/te:label-restrictions/"
        + "te:label-restriction/te:label-start/"
        + "te:te-label/te:technology" {
    description
      "Augment TE label range start for the egress segment
      of the primay path.";
    case wdm {
      uses l0-types:wdm-label-start-end;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:primary-paths/te:primary-path/"
        + "te:path-out-segment/te:label-restrictions/"
        + "te:label-restriction/te:label-end/"
        + "te:te-label/te:technology" {
    description
      "Augment TE label range end for the egress segment
      of the primay path.";
    case wdm {
      uses l0-types:wdm-label-start-end;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:primary-paths/te:primary-path/"
        + "te:path-out-segment/te:label-restrictions/"
        + "te:label-restriction/te:label-step/te:technology" {
    description
      "Augment TE label range end for the egress segment
      of the primay path.";
    case wdm {
      uses l0-types:wdm-label-step;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:primary-paths/te:primary-path/"
        + "te:computed-paths-properties/"
        + "te:computed-path-properties/te:path-properties/"
        + "te:path-route-objects/te:path-route-object/"
        + "te:type/te:label/"
        + "te:label-hop/te:te-label/te:technology" {
    description
      "Augment TE label hop for the route object of the computed
      primary path.";
    case wdm {
      uses l0-types:wdm-label-hop;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:primary-paths/te:primary-path/"
        + "te:primary-reverse-path/"
        + "te:optimizations/te:algorithm/te:metric/"
        + "te:optimization-metric/te:explicit-route-exclude-objects/"
        + "te:route-object-exclude-object/te:type/te:label/"
        + "te:label-hop/te:te-label/te:technology" {
    description
      "Augment TE label hop for the optimization of the explicit
      route objects excluded by the path computation of the primary
      reverse path.";
    case wdm {
      uses l0-types:wdm-label-hop;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:primary-paths/te:primary-path/"
        + "te:primary-reverse-path/"
        + "te:optimizations/te:algorithm/te:metric/"
        + "te:optimization-metric/te:explicit-route-include-objects/"
        + "te:route-object-include-object/te:type/te:label/"
        + "te:label-hop/te:te-label/te:technology" {
    description
      "Augment TE label hop for the optimization of the explicit
      route objects included by the path computation of the primary
      reverse path.";
    case wdm {
      uses l0-types:wdm-label-hop;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:primary-paths/te:primary-path/"
        + "te:primary-reverse-path/"
        + "te:explicit-route-objects-always/"
        + "te:route-object-exclude-always/"
        + "te:type/te:label/"
        + "te:label-hop/te:te-label/te:technology" {
    description
      "Augment TE label hop for the explicit route objects always
      excluded by the path computation of the primary reverse
      path.";
    case wdm {
      uses l0-types:wdm-label-hop;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:primary-paths/te:primary-path/"
        + "te:primary-reverse-path/"
        + "te:explicit-route-objects-always/"
        + "te:route-object-include-exclude/"
        + "te:type/te:label/"
        + "te:label-hop/te:te-label/te:technology" {
    description
      "Augment TE label hop for the explicit route objects included
      or excluded by the path computation of the primary reverse
      path.";
    case wdm {
      uses l0-types:wdm-label-hop;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:primary-paths/te:primary-path/"
        + "te:primary-reverse-path/"
        + "te:path-in-segment/te:label-restrictions/"
        + "te:label-restriction/te:label-start/"
        + "te:te-label/te:technology" {
    description
      "Augment TE label range start for the ingress segment
      of the primay reverse path.";
    case wdm {
      uses l0-types:wdm-label-start-end;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:primary-paths/te:primary-path/"
        + "te:primary-reverse-path/"
        + "te:path-in-segment/te:label-restrictions/"
        + "te:label-restriction/te:label-end/"
        + "te:te-label/te:technology" {
    description
      "Augment TE label range end for the ingress segment
      of the primay reverse path.";
    case wdm {
      uses l0-types:wdm-label-start-end;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:primary-paths/te:primary-path/"
        + "te:primary-reverse-path/"
        + "te:path-in-segment/te:label-restrictions/"
        + "te:label-restriction/te:label-step/te:technology" {
    description
      "Augment TE label range step for the ingress segment
      of the primay reverse path.";
    case wdm {
      uses l0-types:wdm-label-step;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:primary-paths/te:primary-path/"
        + "te:primary-reverse-path/"
        + "te:path-out-segment/te:label-restrictions/"
        + "te:label-restriction/te:label-start/"
        + "te:te-label/te:technology" {
    description
      "Augment TE label range start for the egress segment
      of the primay reverse path.";
    case wdm {
      uses l0-types:wdm-label-start-end;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:primary-paths/te:primary-path/"
        + "te:primary-reverse-path/"
        + "te:path-out-segment/te:label-restrictions/"
        + "te:label-restriction/te:label-end/"
        + "te:te-label/te:technology" {
    description
      "Augment TE label range end for the egress segment
      of the primay reverse path.";
    case wdm {
      uses l0-types:wdm-label-start-end;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:primary-paths/te:primary-path/"
        + "te:primary-reverse-path/"
        + "te:path-out-segment/te:label-restrictions/"
        + "te:label-restriction/te:label-step/te:technology" {
    description
      "Augment TE label range step for the egress segment
      of the primay reverse path.";
    case wdm {
      uses l0-types:wdm-label-step;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:primary-paths/te:primary-path/"
        + "te:primary-reverse-path/"
        + "te:computed-paths-properties/te:computed-path-properties/"
        + "te:path-properties/te:path-route-objects/"
        + "te:path-route-object/te:type/te:label/"
        + "te:label-hop/te:te-label/te:technology" {
    description
      "Augment TE label hop for the route object of the computed
      primary reverse path.";
    case wdm {
      uses l0-types:wdm-label-hop;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:secondary-paths/te:secondary-path/"
        + "te:optimizations/te:algorithm/te:metric/"
        + "te:optimization-metric/te:explicit-route-exclude-objects/"
        + "te:route-object-exclude-object/te:type/te:label/"
        + "te:label-hop/te:te-label/te:technology" {
    description
      "Augment TE label hop for the optimization of the explicit
      route objects excluded by the path computation of the
      secondary path.";
    case wdm {
      uses l0-types:wdm-label-hop;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:secondary-paths/te:secondary-path/"
        + "te:optimizations/te:algorithm/te:metric/"
        + "te:optimization-metric/te:explicit-route-include-objects/"
        + "te:route-object-include-object/te:type/te:label/"
        + "te:label-hop/te:te-label/te:technology" {
    description
      "Augment TE label hop for the optimization of the explicit
      route objects included by the path computation of the
      secondary path.";
    case wdm {
      uses l0-types:wdm-label-hop;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:secondary-paths/te:secondary-path/"
        + "te:explicit-route-objects-always/"
        + "te:route-object-exclude-always/te:type/te:label/"
        + "te:label-hop/te:te-label/te:technology" {
    description
      "Augment TE label hop for the explicit route objects always
      excluded by the path computation of the secondary path.";
    case wdm {
      uses l0-types:wdm-label-hop;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:secondary-paths/te:secondary-path/"
        + "te:explicit-route-objects-always/"
        + "te:route-object-include-exclude/te:type/te:label/"
        + "te:label-hop/te:te-label/te:technology" {
    description
      "Augment TE label hop for the explicit route objects included
      or excluded by the path computation of the secondary path.";
    case wdm {
      uses l0-types:wdm-label-hop;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:secondary-paths/te:secondary-path/"
        + "te:path-in-segment/te:label-restrictions/"
        + "te:label-restriction/te:label-start/"
        + "te:te-label/te:technology" {
    description
      "Augment TE label range start for the ingress segment
      of the secondary path.";
    case wdm {
      uses l0-types:wdm-label-start-end;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:secondary-paths/te:secondary-path/"
        + "te:path-in-segment/te:label-restrictions/"
        + "te:label-restriction/te:label-end/"
        + "te:te-label/te:technology" {
    description
      "Augment TE label range end for the ingress segment
      of the secondary path.";
    case wdm {
      uses l0-types:wdm-label-start-end;
    }
  }
  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:secondary-paths/te:secondary-path/"
        + "te:path-in-segment/te:label-restrictions/"
        + "te:label-restriction/te:label-step/te:technology" {
    description
      "Augment TE label range step for the ingress segment
      of the secondary path.";
    case wdm {
      uses l0-types:wdm-label-step;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:secondary-paths/te:secondary-path/"
        + "te:path-out-segment/te:label-restrictions/"
        + "te:label-restriction/te:label-start/"
        + "te:te-label/te:technology" {
    description
      "Augment TE label range start for the egress segment
      of the secondary path.";
    case wdm {
      uses l0-types:wdm-label-start-end;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:secondary-paths/te:secondary-path/"
        + "te:path-out-segment/te:label-restrictions/"
        + "te:label-restriction/te:label-end/"
        + "te:te-label/te:technology" {
    description
      "Augment TE label range end for the egress segment
      of the secondary path.";
    case wdm {
      uses l0-types:wdm-label-start-end;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:secondary-paths/te:secondary-path/"
        + "te:path-out-segment/te:label-restrictions/"
        + "te:label-restriction/te:label-step/te:technology" {
    description
      "Augment TE label range step for the egress segment
      of the secondary path.";
    case wdm {
      uses l0-types:wdm-label-step;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:secondary-paths/te:secondary-path/"
        + "te:computed-paths-properties/"
        + "te:computed-path-properties/"
        + "te:path-properties/te:path-route-objects/"
        + "te:path-route-object/te:type/te:label/"
        + "te:label-hop/te:te-label/te:technology" {
    description
      "Augment TE label hop for the route object of the computed
      secondary path.";
    case wdm {
      uses l0-types:wdm-label-hop;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:secondary-reverse-paths/te:secondary-reverse-path/"
        + "te:optimizations/te:algorithm/te:metric/"
        + "te:optimization-metric/te:explicit-route-exclude-objects/"
        + "te:route-object-exclude-object/te:type/te:label/"
        + "te:label-hop/te:te-label/te:technology" {
    description
      "Augment TE label hop for the optimization of the explicit
      route objects excluded by the path computation of the
      secondary reverse path.";
    case wdm {
      uses l0-types:wdm-label-hop;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:secondary-reverse-paths/te:secondary-reverse-path/"
        + "te:optimizations/te:algorithm/te:metric/"
        + "te:optimization-metric/te:explicit-route-include-objects/"
        + "te:route-object-include-object/te:type/te:label/"
        + "te:label-hop/te:te-label/te:technology" {
    description
      "Augment TE label hop for the optimization of the explicit
      route objects included by the path computation of the
      secondary reverse path.";
    case wdm {
      uses l0-types:wdm-label-hop;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:secondary-reverse-paths/te:secondary-reverse-path/"
        + "te:explicit-route-objects-always/"
        + "te:route-object-exclude-always/te:type/te:label/"
        + "te:label-hop/te:te-label/te:technology" {
    description
      "Augment TE label hop for the explicit route objects always
      excluded by the path computation of the secondary reverse
      path.";
    case wdm {
      uses l0-types:wdm-label-hop;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:secondary-reverse-paths/te:secondary-reverse-path/"
        + "te:explicit-route-objects-always/"
        + "te:route-object-include-exclude/te:type/te:label/"
        + "te:label-hop/te:te-label/te:technology" {
    description
      "Augment TE label hop for the explicit route objects included
      or excluded by the path computation of the secondary reverse
      path.";
    case wdm {
      uses l0-types:wdm-label-hop;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:secondary-reverse-paths/te:secondary-reverse-path/"
        + "te:path-in-segment/te:label-restrictions/"
        + "te:label-restriction/te:label-start/"
        + "te:te-label/te:technology" {
    description
      "Augment TE label range start for the ingress segment
      of the secondary reverse path.";
    case wdm {
      uses l0-types:wdm-label-start-end;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:secondary-reverse-paths/te:secondary-reverse-path/"
        + "te:path-in-segment/te:label-restrictions/"
        + "te:label-restriction/te:label-end/"
        + "te:te-label/te:technology" {
    description
      "Augment TE label range end for the ingress segment
      of the secondary reverse path.";
    case wdm {
      uses l0-types:wdm-label-start-end;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:secondary-reverse-paths/te:secondary-reverse-path/"
        + "te:path-in-segment/te:label-restrictions/"
        + "te:label-restriction/te:label-step/te:technology" {
    description
      "Augment TE label range step for the ingress segment
      of the secondary reverse path.";
    case wdm {
      uses l0-types:wdm-label-step;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:secondary-reverse-paths/te:secondary-reverse-path/"
        + "te:path-out-segment/te:label-restrictions/"
        + "te:label-restriction/te:label-start/"
        + "te:te-label/te:technology" {
    description
      "Augment TE label range start for the egress segment
      of the secondary reverse path.";
    case wdm {
      uses l0-types:wdm-label-start-end;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:secondary-reverse-paths/te:secondary-reverse-path/"
        + "te:path-out-segment/te:label-restrictions/"
        + "te:label-restriction/te:label-end/"
        + "te:te-label/te:technology" {
    description
      "Augment TE label range end for the egress segment
      of the secondary reverse path.";
    case wdm {
      uses l0-types:wdm-label-start-end;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:secondary-reverse-paths/te:secondary-reverse-path/"
        + "te:path-out-segment/te:label-restrictions/"
        + "te:label-restriction/te:label-step/te:technology" {
    description
      "Augment TE label range step for the egress segment
      of the secondary reverse path.";
    case wdm {
      uses l0-types:wdm-label-step;
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:secondary-reverse-paths/te:secondary-reverse-path/"
        + "te:computed-paths-properties/"
        + "te:computed-path-properties/"
        + "te:path-properties/te:path-route-objects/"
        + "te:path-route-object/te:type/te:label/"
        + "te:label-hop/te:te-label/te:technology" {
    description
      "Augment TE label hop for the route object of the computed
      secondary reverse path.";
    case wdm {
      uses l0-types:wdm-label-hop;
    }
  }

  augment "/te:te/te:lsps/"
        + "te:lsp/te:lsp-actual-route-information/"
        + "te:lsp-actual-route-information/te:type/te:label/"
        + "te:label-hop/te:te-label/te:technology" {
    description
      "Augment TE label hop for the actual route of the LSP.";
    case wdm {
      uses l0-types:wdm-label-hop;
    }
  }
}

<CODE ENDS>

6. 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] or RESTCONF [RFC8040]. 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.

There are a number of data nodes defined in this YANG module that are writable/creatable/deletable (i.e., config true, which is the default). These data nodes may be considered sensitive or vulnerable in some network environments. Write operations (e.g., edit-config) to these data nodes without proper protection can have a negative effect on network operations. These are the subtrees and data nodes and their sensitivity/vulnerability:

  • /te:te/te:tunnels/te:tunnel

  • /te:te/.../te:te-bandwidth/te:technology

  • /te:te/.../te:type/te:label/te:label-hop/te:te-label/te:technology

  • /te:te/.../te:label-restrictions/te:label-restriction/te:label- start/te:te-label/te:technology

  • /te:te/.../te:label-restrictions/te:label-restriction/te:label- end/te:te-label/te:technology

  • /te:te/.../te:label-restrictions/te:label-restriction/

Editors note: we are using simplified description by folding similar branches to avoid repetition.

7. 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-wdm-tunnel
   Registrant Contact: The IESG
   XML: N/A; the requested URI is an XML namespace.

This document registers the following YANG module in the YANG Module Names registry [RFC6020].

   name: ietf-wdm-tunnel
   namespace: urn:ietf:params:xml:ns:yang:ietf-wdm-tunnel
   prefix: wdm-tnl
   reference: RFC XXXX

8. References

8.1. Normative References

[I-D.ietf-ccamp-flexigrid-yang]
de Madrid, U. A., Burrero, D. P., King, D., Lee, Y., and H. Zheng, "A YANG Data Model for Flexi-Grid Optical Networks", Work in Progress, Internet-Draft, draft-ietf-ccamp-flexigrid-yang-15, , <https://datatracker.ietf.org/doc/html/draft-ietf-ccamp-flexigrid-yang-15>.
[I-D.ietf-teas-yang-te]
Saad, T., Gandhi, R., Liu, X., Beeram, V. P., and I. Bryskin, "A YANG Data Model for Traffic Engineering Tunnels, Label Switched Paths and Interfaces", Work in Progress, Internet-Draft, draft-ietf-teas-yang-te-34, , <https://datatracker.ietf.org/doc/html/draft-ietf-teas-yang-te-34>.
[RFC2119]
Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, , <https://www.rfc-editor.org/info/rfc2119>.
[RFC3688]
Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, , <https://www.rfc-editor.org/info/rfc3688>.
[RFC6020]
Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, , <https://www.rfc-editor.org/info/rfc6020>.
[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>.
[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>.
[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>.
[RFC8174]
Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, , <https://www.rfc-editor.org/info/rfc8174>.
[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>.
[RFC9094]
Zheng, H., Lee, Y., Guo, A., Lopez, V., and D. King, "A YANG Data Model for Wavelength Switched Optical Networks (WSONs)", RFC 9094, DOI 10.17487/RFC9094, , <https://www.rfc-editor.org/info/rfc9094>.

8.2. Informative References

[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>.
[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>.

Acknowledgments

This work is also partially funded by the Spanish State Research Agency under the project AgileMon (AEI PID2019-104451RB-C21) and by the Spanish Ministry of Science, Innovation and Universities under the program for the training of university lecturers (Grant number: FPU19/05678).

Contributors

Daniel King
Old Dog Consulting
Haomian Zheng
Huawei Technologies
H1, Xiliu Beipo Village, Songshan Lake
Dongguan
China
Italo Busi
Huawei Technologies
Oscar Gonzalez de Dios
Telefonica
Victor Lopez
Nokia
Dieter Beller
Nokia
Ricard Vilalta
CTTC
Young Lee
Samsung
Bin Yeong Yoon
ETRI
Daniel Michaud Vallinoto
Universidad Autonoma de Madrid
Zafar Ali
Cisco

Authors' Addresses

Aihua Guo
Futurewei Technologies
Sergio Belotti
Nokia
G. Galimberti
Individual
Jorge E. Lopez de Vergara Mendez
Naudit HPCN
Daniel Perdices Burrero
Universidad Autonoma de Madrid