YANG Data Models for fine grain Optical Transport Network

Internet-Draft	Fine grain OTN YANG	October 2024
Tan, et al.	Expires 24 April 2025	[Page]

Abstract

This document defines YANG data models to describe the topology and tunnel information of a fine grain Optical Transport Network. The YANG data models defined in this document are designed to meet the requirements for efficient transmission of sub-1G client signals in transport network.¶

1. Introduction

Optical Transport Networks (OTN) is a mainstream layer 1 technology for the transport network. Over the years, it has continued to evolve, to improve its transport functions for the emerging requirements. The topology and tunnel information in the OTN has already been defined by generic traffic-engineering models and technology-specific models, including [I-D.ietf-ccamp-otn-topo-yang] and [I-D.ietf-ccamp-otn-tunnel-model].¶

In the latest version of OTN, ITU-T G.709/Y.1331 Edition 6.5 [ITU-T_G.709], the fine grain OTN (fgOTN) is introduced for the efficient transmission of low rate client signals (e.g., sub-1G).¶

This document presents the control interface requirements of fgOTN, and defines two YANG data models for fgOTN topology and fgOTN tunnel. The topology model can capture topological and resource-related information pertaining to fgOTN. This model also enables clients, which interact with a transport domain controller, for fgOTN topology related operations such as obtaining the relevant topology resource information. The fgOTN tunnel YANG data model defined in this document is used for the provisioning and management of fgOTN Traffic Engineering (TE) tunnels, Label Switched Paths (LSPs), and interfaces.¶

Furthermore, this document also imports the generic Layer 1 types defined in [I-D.ietf-ccamp-layer1-types].¶

The YANG data models defined in this document conform to the Network Management Datastore Architecture (NMDA) defined in [RFC8342].¶

1.1. Terminology and Notations

Some of the key terms used in this document are listed as follow.¶

fgTS: fine grain Tributary Slot.¶
fgODUflex: fine grain Optical channel Data Unit flex¶

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¶

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

1.2. Requirements Notation

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.¶

1.3. Tree Diagram

A simplified graphical representation of the data model is used in Section 6 of this document. The meaning of the symbols in this diagram is defined in [RFC8340].¶

1.4. Requirements Language

1.5. Prefixes in Model Names

In this documents, names of data nodes and other data model objects are prefixed using the standard prefix associated with the corresponding YANG imported modules, as shown in the following table.¶

Table 1: Prefixes and corresponding YANG modules
Prefix	Yang Module	Reference
l1-types	ietf-layer1-types	[RFC YYYY]
otnt	ietf-otn-topology	[RFC ZZZZ]
te	ietf-te	[RFC KKKK]
otn-tnl	ietf-otn-tunnel	[RFC JJJJ]
fgotnt	ietf-fgotn-topology	RFC XXXX
fgotn-tnl	ietf-fgotn-tunnel	RFC XXXX

RFC Editor Note: Please replace XXXX with the number assigned to the RFC once this draft becomes an RFC. Please replace YYYY with the RFC numbers assigned to [I-D.ietf-ccamp-layer1-types]. Please replace ZZZZ with the RFC numbers assigned to [I-D.ietf-ccamp-otn-topo-yang]. Please replace KKKK with the RFC numbers assigned to [I-D.ietf-teas-yang-te]. Please replace JJJJ with the RFC numbers assigned to [I-D.ietf-ccamp-otn-tunnel-model]. Please remove this note.¶

1.6. Model Tree Diagrams

The tree diagrams extracted from the module(s) defined in this document are given in subsequent sections as per the syntax defined in [RFC8340].¶

2. Fine grain Optical Transport Network Scenarios Overview

FgOTN layer network is a service layer network of the OTN ODU layer network. In order to provide fgOTN capabilities, this document defines two extension YANG data models augmenting to TE topology and TE tunnel YANG model. The attributes related to fgOTN are augments from OTN topology data model, and fgOTN topology is not treated as a separate hierarchy. The fgOTN tunnel is defined as a separate tunnel hierarchy, and new fgOTN tunnels need to be pre-set and created during the service provisioning process.¶

The typical scenarios for fgOTN is to provide low bit rate private line or private network services for customers. Three scenarios that require special consideration are listed based on the characteristics of the fgOTN.¶

2.1. Private Line Service Provisioning Scenario of fgOTN

OTN network will cover a larger scope of networks, it may include the backbone network, metro core, metro aggregation, metro access, and even the OTN CPE in the customers' networks.¶

Figure 1 below shows an example of scenario to retrieve server tunnels. In this example, some small bandwidth fgOTN service are aggregated by the access ring (10G), and then aggregated into a bigger bandwidth in metro ring (100G). The allocation of TS maybe different in access ring and metro ring. E.g. there could be 3 timeslots allocated in the access ring while there could be 3 ODU2 are allocated in the metro ring.¶

      +-----+
      |     | \                                 |
      +-----+  \            Domain 1            |      Domain 2
         |      \                               |
         |  10G  \                              |
         |        \                             |
      +-----+       +-----+         +-----+     |     +-----+
      |     | \     |     |---------|     |-----------|     |---------
      +-----+  \  / +-----+         +-----+           +-----+
                \/    |      100G      |                 |    100G
                /\    |                |                 |
      +-----+  /  \ +-----+         +-----+           +-----+
      |     | /     |     |---------|     |-----------|     |---------
      +-----+       +-----+         +-----+           +-----+
         |         /
         |  10G   /
         |       /
      +-----+   /
      |     |  /
      +-----+

Figure 1: The Scenario to Retrieve Server Tunnels

2.2. Service Protection Scenario of fgOTN

As described in [ITU-T_G.709], the functional requirements of fgOTN include Support fgODUflex SNCP 1+1 protection. The protection of fgOTN service should rely on the protection of fgOTN tunnel. The server should provide all the hops of fgOTN tunnel, if the nodes cannot support fgOTN switching, the fg-ts in the LSP can be empty.¶

                   +-----+            +-----+
              -----|  f  |------------| N-f |-----
              |    +-----+            +-----+    |
              |                                  |
           +-----+                            +-----+
           |  f  |                            |  f  |
           +-----+                            +-----+
              |                                  |
              |    +-----+            +-----+    |
              -----| N-f |------------|  f  |-----
                   +-----+            +-----+

Figure 2: A New Protection Scenario of fgOTN

2.3. Hitless Resizing Scenario of fgOTN

[ITU-T_G.709] defines the data plane procedure to support fgODUflex hitless resizing. The support of management of hitless resizing of fgODUflex needs to be further considered. Firstly, the range of fgOTN service's Bandwidth on Demand (BoD) cannot exceed its server layer's bandwidth. Secondly, the client needs to know how many bandwidth of a link is allocated for fgOTN. From a management point of view, we only need to plan a portion of resources to support fgOTN, without having to allocate all resources for fgOTN to use. As shown in Figure 3, only resource 1 is planned for fgOTN.¶

   +--------+                           +-------------+
   |        |---------------------------|             |
   |        |  Resource 1               |             |
   | Source |---------------------------| destination |
   |  node  |  Resource 2               |    node     |
   |        |---------------------------|             |
   +--------+                           +-------------+
    | | |                                  | | |
    | | |            +----------+          | | |
    | | +------------|          |----------+ | |
    | |   Resource 1 |  Interm  |            | |
    | +--------------|  ediate  |------------+ |
    |     Resource 2 |   node   |              |
    +----------------|          |--------------+
                     +----------+

Figure 3: The Range of fgOTN service's BOD

4. Fine Grain OTN Topology Data Model Overview

This document aims to describe the data model for fine grain OTN topology. The YANG module presented in this document augments from OTN topology data model, i.e., the ietf-otn-topology, as specified in [I-D.ietf-ccamp-otn-topo-yang]. In section 6 of [I-D.ietf-ccamp-otn-topo-yang], the guideline for augmenting OTN topology model was provided, and in this draft, we augment the OTN topology model to describe the topology characteristics of fgOTN.¶

Common types, identities and groupings defined in [I-D.ietf-ccamp-layer1-types] is reused in this document.¶

[RFC8345] defines an abstract (generic, or base) YANG data model for network/service topologies and inventories, and provides the fundamental model for [RFC8795]. OTN topology module in [I-D.ietf-ccamp-otn-topo-yang] augments from the TE topology YANG model defined in [RFC8795]. This work is not directly augmenting [RFC8345]. Figure 4 shows the augmentation relationship.¶

    +--------------+      +-----------------------+
    | ietf-network |      | ietf-network-topology |
    +--------------+      +-----------------------+
                ^             ^
                |_____   _____|
                      | |
                      | | Augments
             +-------------------+
             | ietf-te-topology  |
             +-------------------+
                       ^
                       | Augments
                       |
             +-------------------+
             | ietf-otn-topology |
             +-------------------+
                       ^
                       | Augments
                       |
            +----------+----------+
            | ietf-fgotn-topology |
            +---------------------+

Figure 4: Relationship between fgOTN topology and OTN topology model

The entities, TE attributes and OTN attributes, such as node, termination points and links, are still applicable for describing an fgOTN topology and the model presented in this document only specifies technology-specific attributes/information. The fgOTN-specific attributes including the fgTS, can be used to represent the bandwidth and label information. At the same time, it is necessary to extend the encoding and switching-capability enumeration values in [I-D.busi-teas-te-types-update] to support fgOTN encapsulation and fgOTN switching.¶

4.1. Attributes Augmentation

There are a few characteristics augmenting to the OTN topology.¶

The fine grain tributary slot granularity (FGTSG) attribute defines the granularity, such as 10M, used by the TSs of a given OTN link.¶

A boolean value is specified to augment the generic TE link termination point to describe whether the point can support fgOTN switching capability.¶

augment /nw:networks/nw:network/nw:node/nt:termination-point/tet:te:
   +--rw supported-fgotn-tp?   boolean

The boolean value supported-fgodu-tp is used to indicate whether the termination point can support fgOTN switching capability.¶

4.2. Bandwidth Augmentation

Based on the OTN topology model, we augment the bandwidth information of fgOTN, including the max-link-bandwidth and unreserved-bandwidth. The augmented parameter fgotn-bandwidth is used to indicate how much of the bandwidth has been allocated for the usage of fgOTN.¶

augment /nw:networks/nw:network/nt:link/tet:te/tet:te-link-attributes
          /tet:max-link-bandwidth/tet:te-bandwidth/otnt:otn-bandwidth
          /otnt:odulist:
   +--rw fgotn-bandwidth?   string

The augmented fgotnlist structure is used to describe the unreserved TE bandwidth of fgOTN in the server ODUk. The odu-ts-number is used to indicate the index of server ODUk channel.¶

augment /nw:networks/nw:network/nt:link/tet:te/tet:te-link-attributes
          /tet:unreserved-bandwidth/tet:te-bandwidth
          /otnt:otn-bandwidth:
   +--rw fgotnlist* [odu-type odu-ts-number]
      +--rw odu-type           identityref
      +--rw odu-ts-number?     uint16
      +--rw fgotn-bandwidth?   string

4.3. Label Augmentation

The model augments the label-restriction list with fgOTN technology specific attributes using the otn-label-range-info grouping defined in [I-D.ietf-ccamp-layer1-types].¶

augment /nw:networks/tet:te/tet:templates/tet:link-template
        /tet:te-link-attributes/tet:label-restrictions
        /tet:label-restriction/otnt:otn-label-range:
   +--rw fgts-range* [odu-type odu-ts-number]
      +--rw odu-type           identityref
      +--rw odu-ts-number?     string
      +--rw fgts-reserved?     string
      +--rw fgts-unreserved?   string

The fgts-range list is used to describe the availability of fgOTN timeslot in the server ODUk, including the fgts-reserved and fgts-unreserved. The odu-ts-number is used to indicate the index of server ODUk channel.¶

5. Fine Grain OTN Tunnel Data Model Overview

This document aims to describe the data model for fgOTN tunnel. The fgOTN tunnel model augments to OTN tunnel [I-D.ietf-ccamp-otn-tunnel-model] with fgOTN-specific parameters, including the bandwidth information and label information. Figure 5 shows the augmentation relationship.¶

                +------------------+
                |      ietf-te     |
                +------------------+
                          ^
                          | Augments
                          |
                +-----------------+
                | ietf-otn-tunnel |
                +-----------------+
                          ^
                          | Augments
                          |
               +----------+--------+
               | ietf-fgotn-tunnel |
               +-------------------+

Figure 5: Relationship between fgOTN and OTN tunnel model

It's also worth noting that the fgOTN tunnel provisioning is usually based on the fgOTN topology. Therefore the fgOTN tunnel model is usually used together with fgOTN topology model specified in this document. The OTN tunnel model also imports a few type modules, including ietf-te-types and ietf-otn-types. A new enumeration value prot-fgoduflex in ietf-otn-types should be defined to indicate the fgotn tunnel.¶

5.1. Bandwidth Augmentation

The model augment TE bandwidth information of fgOTN tunnel.¶

augment /te:te/te:tunnels/te:tunnel/te:te-bandwidth/te:technology
        /otn-tnl:otn:
   +--rw fgoduflex-bandwidth?   string

The string value fgoduflex-bandwidth is used to indicate the bandwidth of this fgOTN tunnel.¶

5.2. Label Augmentation

The module augments TE label-hop for the explicit route objects included or excluded by the path computation of the primary paths and secondary-paths using the fgts-numbers. The fgts-numbers is used to specify fgTS information on inter-domain ports of the routing path. We also augment the TE label-hop for the record route of the LSP using the fgts-numbers.¶

6. YANG Tree for fgOTN topology

Figure 6 below shows the tree diagram of the YANG data model defined in module "ietf-fgotn-topology" (Figure 7).¶

module: ietf-fgotn-topology

  augment /nw:networks/nw:network/nw:node/nt:termination-point
            /tet:te:
    +--rw supported-fgotn-tp?   boolean
  augment /nw:networks/nw:network/nt:link/tet:te
            /tet:te-link-attributes/tet:max-link-bandwidth
            /tet:te-bandwidth/otnt:otn-bandwidth/otnt:odulist:
    +--rw fgotn-bandwidth?   string
  augment /nw:networks/nw:network/nt:link/tet:te
            /tet:te-link-attributes/tet:unreserved-bandwidth
            /tet:te-bandwidth/otnt:otn-bandwidth:
    +--rw fgotnlist* [odu-type odu-ts-number]
       +--rw odu-type           identityref
       +--rw odu-ts-number      uint16
       +--rw fgotn-bandwidth?   string
  augment /nw:networks/tet:te/tet:templates/tet:link-template
            /tet:te-link-attributes/tet:label-restrictions
            /tet:label-restriction/otnt:otn-label-range:
    +--rw fgts-range* [odu-type odu-ts-number]
       +--rw odu-type           identityref
       +--rw odu-ts-number      string
       +--rw fgts-reserved?     string
       +--rw fgts-unreserved?   string

Figure 6

7. YANG Data Model for fgOTN topology

<CODE BEGINS> file "ietf-fgotn-topology@2024-07-07.yang"

 module ietf-fgotn-topology {
   /* TODO: FIXME */
  yang-version 1.1;

  namespace "urn:ietf:params:xml:ns:yang:ietf-fgotn-topology";
  prefix "fgotnt";

  import ietf-network {
    prefix "nw";
    reference
      "RFC8345: A YANG Data Model for Network Topologies";
  }

  import ietf-network-topology {
    prefix "nt";
    reference
      "RFC8345: A YANG Data Model for Network Topologies";
  }

  import ietf-te-topology {
    prefix "tet";
    reference
      "RFC 8795: YANG Data Model for Traffic Engineering (TE)
                 Topologies";
  }

  import ietf-layer1-types {
    prefix "l1-types";
    reference
      "RFC YYYY: A YANG Data Model for Layer 1 Types";
  }

  /* Note: The RFC Editor will replace YYYY with the number assigned
     to the RFC once draft-ietf-ccamp-layer1-types becomes an RFC.*/

  import ietf-otn-topology {
    prefix "otnt";
    reference
      "RFC ZZZZ: A YANG Data Model for Optical Transport Network
                 Topology";
  }

  /* Note: The RFC Editor will replace ZZZZ with the number assigned
     to the RFC once draft-ietf-ccamp-otn-topo-yang becomes an RFC.*/

  organization
    "Internet Engineering Task Force (IETF) CCAMP WG";
  contact
    "
      ID-draft editor:
        Yanxia Tan (tanyx11@chinaunicom.cn);
        Yanlei Zheng (zhengyanlei@chinaunicom.cn);
        Italo Busi (italo.busi@huawei.com);
        Chaode Yu (yuchaode@huawei.com);
    ";

  description
    "This module defines a YANG data model for fgOTN-specific
     extension based on existing network topology models. The model
     fully conforms to the Network Management Datastore Architecture
     (NMDA).

     Copyright (c) 2024 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 Revised 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.";

  // RFC Ed.: replace XXXX with actual RFC number and remove this
  // note.
  // RFC Ed.: update the date below with the date of RFC publication
  // and remove this note.

  revision 2024-07-07 {
    description
      "initial version";
    reference
      "RFC XXXX: YANG Data Models for fine grain Optical Transport
                 Network";
  }

  augment "/nw:networks/nw:network/nw:node/nt:termination-point" +
          "/tet:te" {
    description
      "specific augmentation of fgOTN termination point";
    leaf supported-fgotn-tp {
      type boolean;
      description
        "It is used to indicate whether the TP can support fgOTN
         switching capability.";
    }
  }

  augment "/nw:networks/nw:network/nt:link/tet:te" +
          "/tet:te-link-attributes/tet:max-link-bandwidth" +
          "/tet:te-bandwidth/otnt:otn-bandwidth/otnt:odulist" {
    description
      "specific augmentation of fgOTN link on maximum link
      bandwidth";
    leaf fgotn-bandwidth {
      type string;
      description
        "It is used to indicate how much of the bandwidth has been
         allocated for the usage of fgOTN.";
    }
  }

  augment "/nw:networks/nw:network/nt:link/tet:te" +
          "/tet:te-link-attributes/tet:unreserved-bandwidth" +
          "/tet:te-bandwidth/otnt:otn-bandwidth" {
    description
      "specific augmentation of fgOTN link on unreserved link
      bandwidth";
    list fgotnlist {
      key "odu-type odu-ts-number";
      description
        "This structure is used to describe the unsreserved
         bandwidth of fgOTN in the server ODUk";
      leaf odu-type {
        type identityref {
          base l1-types:odu-type;
        }
        description
          "The granularity of server ODUk";
      }

      leaf odu-ts-number {
        type uint16;
        description
          "The index of server ODUk channel";
      }

      leaf fgotn-bandwidth {
        type string;
        description
          "The unsreserved bandwidth of fgOTN in this server ODUk";
      }
    }
  }

  augment "/nw:networks/tet:te/tet:templates/tet:link-template"+
          "/tet:te-link-attributes/tet:label-restrictions" +
          "/tet:label-restriction/otnt:otn-label-range" {
    description
      "specific augmentation of fgOTN label";
    list fgts-range {
      key "odu-type odu-ts-number";
      description
        "This structure is used to describe the availability of
         fgOTN timeslot in the server ODUk";
      leaf odu-type {
        type identityref {
          base l1-types:odu-type;
        }
        description
          "The granularity of server ODUk";
      }

      leaf odu-ts-number {
        type string;
        description
          "The index of server ODUk channel";
      }

      leaf fgts-reserved {
        type string;
        description
          "The reserved fgOTN timeslot in this server ODUk";
      }

      leaf fgts-unreserved {
        type string;
        description
          "The unreserved fgOTN timeslot in this server ODUk";
      }
    }
  }
}

<CODE ENDS>

Figure 7: fgOTN topology YANG module

8. YANG Tree for fgOTN tunnel

Figure 8 below shows the tree diagram of the YANG data model defined in module "ietf-fgotn-tunnel" (Figure 9).¶

module: ietf-fgotn-tunnel

  augment /te:te/te:tunnels/te:tunnel/te:te-bandwidth/te:technology
            /otn-tnl:otn:
    +--rw fgoduflex-bandwidth?   string
  augment /te:te/te:tunnels/te:tunnel/te:primary-paths
            /te:primary-path/te:explicit-route-objects
            /te:route-object-include-exclude/te:type/te:label
            /te:label-hop/te:te-label/te:technology/otn-tnl:otn
            /otn-tnl:otn-label:
    +--rw fgts-numbers?   uint16
  augment /te:te/te:tunnels/te:tunnel/te:primary-paths
            /te:primary-path/te:primary-reverse-path
            /te:explicit-route-objects
            /te:route-object-include-exclude/te:type/te:label
            /te:label-hop/te:te-label/te:technology/otn-tnl:otn
            /otn-tnl:otn-label:
    +--rw fgts-numbers?   uint16
  augment /te:te/te:tunnels/te:tunnel/te:secondary-paths
            /te:secondary-path/te:explicit-route-objects
            /te:route-object-include-exclude/te:type/te:label
            /te:label-hop/te:te-label/te:technology/otn-tnl:otn
            /otn-tnl:otn-label:
    +--rw fgts-numbers?   uint16
  augment /te:te/te:tunnels/te:tunnel/te:secondary-reverse-paths
            /te:secondary-reverse-path/te:explicit-route-objects
            /te:route-object-include-exclude/te:type/te:label
            /te:label-hop/te:te-label/te:technology/otn-tnl:otn
            /otn-tnl:otn-label:
    +--rw fgts-numbers?   uint16
  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/otn-tnl:otn
            /otn-tnl:otn-label:
    +--ro fgts-numbers?   uint16

Figure 8

9. YANG Data Model for fgOTN tunnel

<CODE BEGINS> file "ietf-fgotn-tunnel@2024-07-07.yang"

module ietf-fgotn-tunnel {
  /* TODO: FIXME */
  yang-version 1.1;

  namespace "urn:ietf:params:xml:ns:yang:ietf-fgotn-tunnel";
  prefix "fgotn-tnl";

  import ietf-te {
    prefix "te";
    reference
      "RFC KKKK: A YANG Data Model for Traffic Engineering Tunnels,
                 Label Switched Paths and Interfaces";
  }

  /* Note: The RFC Editor will replace KKKK with the number assigned
     to the RFC once draft-ietf-teas-yang-te becomes an RFC.*/

  import ietf-otn-tunnel {
    prefix "otn-tnl";
    reference  "RFC JJJJ: OTN Tunnel YANG Model";
  }

  /* Note: The RFC Editor will replace JJJJ with the number assigned
     to the RFC once draft-ietf-ccamp-otn-tunnel-model becomes
     an RFC.*/

  organization
    "Internet Engineering Task Force (IETF) CCAMP WG";
  contact
    "
      ID-draft editor:
        Yanxia Tan (tanyx11@chinaunicom.cn);
        Yanlei Zheng (zhengyanlei@chinaunicom.cn);
        Italo Busi (italo.busi@huawei.com);
        Chaode Yu (yuchaode@huawei.com);
    ";

  description
    "This module defines a YANG data model for fgOTN-specific
     extension based on existing network topology models. The model
     fully conforms to the Network Management Datastore Architecture
     (NMDA).

     Copyright (c) 2024 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 Revised 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.";

  // RFC Ed.: replace XXXX with actual RFC number and remove this
  // note.
  // RFC Ed.: update the date below with the date of RFC publication
  // and remove this note.

  revision 2024-07-07 {
    description
      "initial version";
    reference
      "RFC XXXX: YANG Data Models for fine grain Optical Transport
                 Network";
  }

  /**
  augment "/te:te/te:tunnels/te:tunnel/te:primary-paths" +
          "/te:primary-path/te:te-bandwidth/te:technology" +
          "/otn-tnl:otn/otn-tnl:otn-bandwidth" {
    leaf fgoduflex-bandwidth {
      type string;
      description
        "The bandwidth of this fgOTN tunnel";
    }
  }
**/

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:te-bandwidth/te:technology/otn-tnl:otn" {
    description
      "augmentation of fgOTN tunnel on bandwidth structure";
    leaf fgoduflex-bandwidth {
      type string;
      description
        "Augment TE bandwidth of the fgOTN tunnel";
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/"
        + "te:primary-paths/te:primary-path/"
        + "te:explicit-route-objects/"
        + "te:route-object-include-exclude/te:type/te:label/"
        + "te:label-hop/te:te-label/te:technology/otn-tnl:otn" +
          "/otn-tnl:otn-label" {
    description
      "augmentation of fgOTN label";
    leaf fgts-numbers {
      type uint16;
      description
        "Augment fgOTN timeslot information of this label hop";
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/te:primary-paths" +
          "/te:primary-path/te:primary-reverse-path" +
          "/te:explicit-route-objects" +
          "/te:route-object-include-exclude/te:type/te:label" +
          "/te:label-hop/te:te-label/te:technology/otn-tnl:otn" +
          "/otn-tnl:otn-label" {
    description
      "augmentation of fgOTN label";
    leaf fgts-numbers {
      type uint16;
      description
        "Augment fgOTN timeslot information of this label hop";
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/te:secondary-paths" +
          "/te:secondary-path/te:explicit-route-objects" +
          "/te:route-object-include-exclude/te:type/te:label" +
          "/te:label-hop/te:te-label/te:technology/otn-tnl:otn" +
          "/otn-tnl:otn-label" {
    description
      "augmentation of fgOTN label";
    leaf fgts-numbers {
      type uint16;
      description
        "fgOTN timeslot information of this label hop";
    }
  }

  augment "/te:te/te:tunnels/te:tunnel/te:secondary-reverse-paths" +
          "/te:secondary-reverse-path/te:explicit-route-objects" +
          "/te:route-object-include-exclude/te:type/te:label" +
          "/te:label-hop/te:te-label/te:technology/otn-tnl:otn" +
          "/otn-tnl:otn-label" {
    description
      "augmentation of fgOTN label";
    leaf fgts-numbers {
      type uint16;
      description
        "fgOTN timeslot information of this 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/otn-tnl:otn" +
          "/otn-tnl:otn-label" {
    description
      "augmentation of fgOTN label";
    leaf fgts-numbers {
      type uint16;
      description
        "fgOTN timeslot information of this label hop";
    }
  }
}

<CODE ENDS>

Figure 9: fgOTN tunnel YANG module

13. References

13.1. Normative References

[I-D.ietf-ccamp-layer1-types]: Zheng, H. and I. Busi, "Common YANG Data Types for Layer 1 Networks", Work in Progress, Internet-Draft, draft-ietf-ccamp-layer1-types-18, 23 February 2024, <https://datatracker.ietf.org/doc/html/draft-ietf-ccamp-layer1-types-18>.
[I-D.ietf-ccamp-otn-topo-yang]: Zheng, H., Busi, I., Liu, X., Belotti, S., and O. G. de Dios, "A YANG Data Model for Optical Transport Network Topology", Work in Progress, Internet-Draft, draft-ietf-ccamp-otn-topo-yang-19, 25 June 2024, <https://datatracker.ietf.org/doc/html/draft-ietf-ccamp-otn-topo-yang-19>.
[I-D.ietf-ccamp-otn-tunnel-model]: Zheng, H., Busi, I., Belotti, S., Lopez, V., and Y. Xu, "OTN Tunnel YANG Model", Work in Progress, Internet-Draft, draft-ietf-ccamp-otn-tunnel-model-21, 6 June 2024, <https://datatracker.ietf.org/doc/html/draft-ietf-ccamp-otn-tunnel-model-21>.
[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-37, 9 October 2024, <https://datatracker.ietf.org/doc/html/draft-ietf-teas-yang-te-37>.
[IANA_YANG]: IANA, "YANG Parameters", n.d., <https://www.iana.org/assignments/yang-parameters>.
[ITU-T_G.709]: ITU-T Recommendation G.709, "Interfaces for the optical transport network", ITU-T Recommendation G.709, Amendment 3 , March 2024, <https://www.itu.int/rec/T-REC-G.709/>.
[RFC2119]: Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, <https://www.rfc-editor.org/rfc/rfc2119>.
[RFC6241]: Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., and A. Bierman, Ed., "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011, <https://www.rfc-editor.org/rfc/rfc6241>.
[RFC7950]: Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016, <https://www.rfc-editor.org/rfc/rfc7950>.
[RFC8174]: Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.
[RFC8340]: Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018, <https://www.rfc-editor.org/rfc/rfc8340>.
[RFC8342]: Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K., and R. Wilton, "Network Management Datastore Architecture (NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018, <https://www.rfc-editor.org/rfc/rfc8342>.

13.2. Informative References

[I-D.busi-teas-te-types-update]: Busi, I., Guo, A., Liu, X., Saad, T., Gandhi, R., Beeram, V. P., and I. Bryskin, "Updated Common YANG Data Types for Traffic Engineering", Work in Progress, Internet-Draft, draft-busi-teas-te-types-update-02, 4 April 2022, <https://datatracker.ietf.org/doc/html/draft-busi-teas-te-types-update-02>.
[RFC8345]: Clemm, A., Medved, J., Varga, R., Bahadur, N., Ananthakrishnan, H., and X. Liu, "A YANG Data Model for Network Topologies", RFC 8345, DOI 10.17487/RFC8345, March 2018, <https://www.rfc-editor.org/rfc/rfc8345>.
[RFC8795]: Liu, X., Bryskin, I., Beeram, V., Saad, T., Shah, H., and O. Gonzalez de Dios, "YANG Data Model for Traffic Engineering (TE) Topologies", RFC 8795, DOI 10.17487/RFC8795, August 2020, <https://www.rfc-editor.org/rfc/rfc8795>.