



CCAMP Working Group                                              I. Busi
Internet-Draft                                       Huawei Technologies
Intended status: Standards Track                                  A. Guo
Expires: 15 October 2026                          Futurewei Technologies
                                                              S. Belotti
                                                                   Nokia
                                                           13 April 2026


    A YANG Data Model for requesting Path Computation in an Optical
                        Transport Network (OTN)
             draft-ietf-ccamp-otn-path-computation-yang-07

Abstract

   This document provides a mechanism to request path computation in an
   Optical Transport Network (OTN) by augmenting the Remote Procedure
   Calls (RPCs) defined in RFC YYYY.

   [RFC EDITOR NOTE: Please replace RFC YYYY with the RFC number of
   draft-ietf-teas-yang-path-computation once it has been published.

About This Document

   This note is to be removed before publishing as an RFC.

   The latest revision of this draft can be found at https://ietf-ccamp-
   wg.github.io/ietf-ccamp-otn-path-computation/draft-ietf-ccamp-otn-
   path-computation-yang.html.  Status information for this document may
   be found at https://datatracker.ietf.org/doc/draft-ietf-ccamp-otn-
   path-computation-yang/.

   Discussion of this document takes place on the Common Control and
   Measurement Plane Working Group mailing list (mailto:ccamp@ietf.org),
   which is archived at https://mailarchive.ietf.org/arch/browse/ccamp/.
   Subscribe at https://www.ietf.org/mailman/listinfo/ccamp/.

   Source for this draft and an issue tracker can be found at
   https://github.com/ietf-ccamp-wg/ietf-ccamp-otn-path-computation.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.







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Copyright Notice

   Copyright (c) 2026 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents (https://trustee.ietf.org/
   license-info) in effect on the date of publication of this document.
   Please review these documents carefully, as they describe your rights
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   extracted from this document must include Revised BSD License text as
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   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.1.  Terminology and Notations . . . . . . . . . . . . . . . .   3
     1.2.  Tree Diagram  . . . . . . . . . . . . . . . . . . . . . .   4
     1.3.  Prefix in Data Node Names . . . . . . . . . . . . . . . .   4
   2.  YANG Data Model for OTN Path Computation  . . . . . . . . . .   4
     2.1.  YANG Model Overview . . . . . . . . . . . . . . . . . . .   4
     2.2.  Bandwidth Augmentation  . . . . . . . . . . . . . . . . .   5
     2.3.  Label Augmentations . . . . . . . . . . . . . . . . . . .   5
   3.  OTN Path Computation Tree Diagram . . . . . . . . . . . . . .   5
   4.  YANG Model for OTN Path Computation . . . . . . . . . . . . .  10
   5.  Manageability Considerations  . . . . . . . . . . . . . . . .  16
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  16
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  17
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  17
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .  17
     8.2.  Informative References  . . . . . . . . . . . . . . . . .  18
   Appendix A.  Change Log . . . . . . . . . . . . . . . . . . . . .  19
   Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . .  19
   Contributors  . . . . . . . . . . . . . . . . . . . . . . . . . .  20
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  20



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1.  Introduction

   [I-D.ietf-teas-yang-path-computation] describes key use cases, where
   a client needs to request underlying SDN controllers for path
   computation.  In some of these use cases, the underlying SDN
   controller can control an Optical Transport Network (OTN).

   This document defines a YANG data model, which augment the generic
   Path Computation RPC defined in
   [I-D.ietf-teas-yang-path-computation], with OTN technology-specific
   augmentations required to request path computation to an underlying
   OTN SDN controller.  These models allow a client to delegate path
   computation tasks to the underlying SDN controller without having to
   obtain OTN detailed information from the controller and performing
   feasible path computation itself.

1.1.  Terminology and Notations

   Refer to [I-D.ietf-ccamp-otn-topo-yang] and
   [I-D.ietf-ccamp-layer1-types] for the OTN specific 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

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







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1.2.  Tree Diagram

   A simplified graphical representation of the data model is used in
   Section 3 of this document.  The meaning of the symbols in these
   diagrams is defined in [RFC8340].

1.3.  Prefix in Data Node Names

   In this document, names of data nodes and other data model objects
   are prefixed using the standard prefix associated with the
   corresponding YANG imported modules, as shown in Table 1.

           +==========+===========================+===========+
           | Prefix   | YANG module               | Reference |
           +==========+===========================+===========+
           | l1-types | ietf-layer1-types         | [RFCZZZZ] |
           +----------+---------------------------+-----------+
           | te       | ietf-te                   | [RFCKKKK] |
           +----------+---------------------------+-----------+
           | te-pc    | ietf-te-path-computation  | [RFCYYYY] |
           +----------+---------------------------+-----------+
           | otn-pc   | ietf-otn-path-computation | RFCXXXX   |
           +----------+---------------------------+-----------+

             Table 1: Prefixes and corresponding YANG modules

      RFC Editor Note: Please replace XXXX with the RFC number assigned
      to this document.  Please replace YYYY with the RFC number
      assigned to [I-D.ietf-teas-yang-path-computation].  Please replace
      ZZZZ with the RFC number assigned to
      [I-D.ietf-ccamp-layer1-types].  Please replace KKKK with the RFC
      number assigned to [I-D.ietf-teas-yang-te].  Please remove this
      note.

2.  YANG Data Model for OTN Path Computation

2.1.  YANG Model Overview

   The YANG data model for requesting OTN path computation is defined as
   an augmentation of the generic Path Computation RPC defined in
   [I-D.ietf-teas-yang-path-computation], as shown in Figure 1.










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                       +--------------------------+    o: augment
          TE generic   | ietf-te-path-computation |
                       +--------------------------+
                                    o
                                    |
                                    |
                                    |
                      +---------------------------+
          OTN         | ietf-otn-path-computation |
                      +---------------------------+

     Figure 1: Relationship between OTN and TE path computation models

   The entities and Traffic Engineering (TE) attributes, such as
   requested path and tunnel attributes, defined in
   [I-D.ietf-teas-yang-path-computation], are still applicable when
   requesting OTN path computation and the models defined in this
   document only specifies the additional OTN technology-specific
   attributes/information, using the attributes defined in
   [I-D.ietf-ccamp-layer1-types].

   The YANG module ietf-otn-path-computation defined in this document
   conforms to the Network Management Datastore Architecture (NMDA)
   defined in [RFC8342].

2.2.  Bandwidth Augmentation

   The OTN path computation model augments all the occurrences of the
   te-bandwidth container with the OTN technology-specific attributes
   using the otn-link-bandwidth and otn-path-bandwidth groupings defined
   in [I-D.ietf-ccamp-layer1-types].

2.3.  Label Augmentations

   The OTN path computation model augments all the occurrences of the
   label-restriction list with OTN technology-specific attributes using
   the otn-label-range-info grouping defined in
   [I-D.ietf-ccamp-layer1-types].

   Moreover, the model augments all the occurrences of the te-label
   container with the OTN technology-specific attributes using the otn-
   label-start-end, otn-label-hop and otn-label-step groupings defined
   in [I-D.ietf-ccamp-layer1-types].

3.  OTN Path Computation Tree Diagram

   Figure 2 below shows the tree diagram of the YANG data model defined
   in module ietf-otn-path-computation.yang.



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   module: ietf-otn-path-computation

     augment /te:tunnels-path-compute/te:input/te:path-compute-info
               /te-pc:path-request/te-pc:te-bandwidth/te-pc:technology:
       +--:(otn)
          +-- otn
             +-- odu-type?                     identityref
             +-- (oduflex-type)?
                +--:(generic)
                |  +-- nominal-bit-rate        union
                +--:(cbr)
                |  +-- client-type             identityref
                +--:(gfp-n-k)
                |  +-- gfp-n                   uint8
                |  +-- gfp-k?                  gfp-k
                +--:(flexe-client)
                |  +-- flexe-client            flexe-client-rate
                +--:(flexe-aware)
                |  +-- flexe-aware-n           uint16
                +--:(packet)
                   +-- opuflex-payload-rate    union
     augment /te:tunnels-path-compute/te:input/te:path-compute-info
               /te-pc:tunnel-attributes/te-pc:te-bandwidth
               /te-pc:technology:
       +--:(otn)
          +-- otn
             +-- odu-type?                     identityref
             +-- (oduflex-type)?
                +--:(generic)
                |  +-- nominal-bit-rate        union
                +--:(cbr)
                |  +-- client-type             identityref
                +--:(gfp-n-k)
                |  +-- gfp-n                   uint8
                |  +-- gfp-k?                  gfp-k
                +--:(flexe-client)
                |  +-- flexe-client            flexe-client-rate
                +--:(flexe-aware)
                |  +-- flexe-aware-n           uint16
                +--:(packet)
                   +-- opuflex-payload-rate    union
     augment /te:tunnels-path-compute/te:output/te:path-compute-result
               /te-pc:response/te-pc:computed-paths-properties
               /te-pc:computed-path-properties/te-pc:path-properties
               /te-pc:te-bandwidth/te-pc:technology:
       +--:(otn)
          +--ro otn
             +--ro odu-type?                     identityref



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             +--ro (oduflex-type)?
                +--:(generic)
                |  +--ro nominal-bit-rate        union
                +--:(cbr)
                |  +--ro client-type             identityref
                +--:(gfp-n-k)
                |  +--ro gfp-n                   uint8
                |  +--ro gfp-k?                  gfp-k
                +--:(flexe-client)
                |  +--ro flexe-client            flexe-client-rate
                +--:(flexe-aware)
                |  +--ro flexe-aware-n           uint16
                +--:(packet)
                   +--ro opuflex-payload-rate    union
     augment /te:tunnels-path-compute/te:input/te:path-compute-info
               /te-pc:path-request/te-pc:path-in-segment
               /te-pc:label-restrictions/te-pc:label-restriction:
       +-- otn-label-range
          +-- range-type?      otn-label-range-type
          +-- tsg?             identityref
          +-- odu-type-list*   identityref
          +-- priority?        uint8
     augment /te:tunnels-path-compute/te:input/te:path-compute-info
               /te-pc:path-request/te-pc:path-out-segment
               /te-pc:label-restrictions/te-pc:label-restriction:
       +-- otn-label-range
          +-- range-type?      otn-label-range-type
          +-- tsg?             identityref
          +-- odu-type-list*   identityref
          +-- priority?        uint8
     augment /te:tunnels-path-compute/te:input/te:path-compute-info
               /te-pc:path-request/te-pc:optimizations/te-pc:algorithm
               /te-pc:metric/te-pc:optimization-metric
               /te-pc:explicit-route-exclude-objects
               /te-pc:route-object-exclude-object/te-pc:type/te-pc:label
               /te-pc:label-hop/te-pc:te-label/te-pc:technology:
       +--:(otn)
          +-- otn
             +-- tpn?       otn-tpn
             +-- tsg?       identityref
             +-- ts-list?   string
     augment /te:tunnels-path-compute/te:input/te:path-compute-info
               /te-pc:path-request/te-pc:optimizations/te-pc:algorithm
               /te-pc:metric/te-pc:optimization-metric
               /te-pc:explicit-route-include-objects
               /te-pc:route-object-include-object/te-pc:type/te-pc:label
               /te-pc:label-hop/te-pc:te-label/te-pc:technology:
       +--:(otn)



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          +-- otn
             +-- tpn?       otn-tpn
             +-- tsg?       identityref
             +-- ts-list?   string
     augment /te:tunnels-path-compute/te:input/te:path-compute-info
               /te-pc:path-request/te-pc:explicit-route-objects-always
               /te-pc:route-object-exclude-always/te-pc:type/te-pc:label
               /te-pc:label-hop/te-pc:te-label/te-pc:technology:
       +--:(otn)
          +-- otn
             +-- tpn?       otn-tpn
             +-- tsg?       identityref
             +-- ts-list?   string
     augment /te:tunnels-path-compute/te:input/te:path-compute-info
               /te-pc:path-request/te-pc:explicit-route-objects-always
               /te-pc:route-object-include-exclude/te-pc:type
               /te-pc:label/te-pc:label-hop/te-pc:te-label
               /te-pc:technology:
       +--:(otn)
          +-- otn
             +-- tpn?       otn-tpn
             +-- tsg?       identityref
             +-- ts-list?   string
     augment /te:tunnels-path-compute/te:input/te:path-compute-info
               /te-pc:path-request/te-pc:path-in-segment
               /te-pc:label-restrictions/te-pc:label-restriction
               /te-pc:label-start/te-pc:te-label/te-pc:technology:
       +--:(otn)
          +-- otn
             +-- (range-type)?
                +--:(trib-port)
                |  +-- tpn?   otn-tpn
                +--:(trib-slot)
                   +-- ts?    otn-ts
     augment /te:tunnels-path-compute/te:input/te:path-compute-info
               /te-pc:path-request/te-pc:path-in-segment
               /te-pc:label-restrictions/te-pc:label-restriction
               /te-pc:label-end/te-pc:te-label/te-pc:technology:
       +--:(otn)
          +-- otn
             +-- (range-type)?
                +--:(trib-port)
                |  +-- tpn?   otn-tpn
                +--:(trib-slot)
                   +-- ts?    otn-ts
     augment /te:tunnels-path-compute/te:input/te:path-compute-info
               /te-pc:path-request/te-pc:path-in-segment
               /te-pc:label-restrictions/te-pc:label-restriction



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               /te-pc:label-step/te-pc:technology:
       +--:(otn)
          +-- otn
             +-- (range-type)?
                +--:(trib-port)
                |  +-- tpn?   otn-tpn
                +--:(trib-slot)
                   +-- ts?    otn-ts
     augment /te:tunnels-path-compute/te:input/te:path-compute-info
               /te-pc:path-request/te-pc:path-out-segment
               /te-pc:label-restrictions/te-pc:label-restriction
               /te-pc:label-start/te-pc:te-label/te-pc:technology:
       +--:(otn)
          +-- otn
             +-- (range-type)?
                +--:(trib-port)
                |  +-- tpn?   otn-tpn
                +--:(trib-slot)
                   +-- ts?    otn-ts
     augment /te:tunnels-path-compute/te:input/te:path-compute-info
               /te-pc:path-request/te-pc:path-out-segment
               /te-pc:label-restrictions/te-pc:label-restriction
               /te-pc:label-end/te-pc:te-label/te-pc:technology:
       +--:(otn)
          +-- otn
             +-- (range-type)?
                +--:(trib-port)
                |  +-- tpn?   otn-tpn
                +--:(trib-slot)
                   +-- ts?    otn-ts
     augment /te:tunnels-path-compute/te:input/te:path-compute-info
               /te-pc:path-request/te-pc:path-out-segment
               /te-pc:label-restrictions/te-pc:label-restriction
               /te-pc:label-step/te-pc:technology:
       +--:(otn)
          +-- otn
             +-- (range-type)?
                +--:(trib-port)
                |  +-- tpn?   otn-tpn
                +--:(trib-slot)
                   +-- ts?    otn-ts
     augment /te:tunnels-path-compute/te:input/te:path-compute-info
               /te-pc:synchronization/te-pc:exclude-objects
               /te-pc:excludes/te-pc:type/te-pc:label/te-pc:label-hop
               /te-pc:te-label/te-pc:technology:
       +--:(otn)
          +-- otn
             +-- tpn?       otn-tpn



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             +-- tsg?       identityref
             +-- ts-list?   string
     augment /te:tunnels-path-compute/te:output/te:path-compute-result
               /te-pc:response/te-pc:computed-paths-properties
               /te-pc:computed-path-properties/te-pc:path-properties
               /te-pc:path-route-objects/te-pc:path-route-object
               /te-pc:type/te-pc:label/te-pc:label-hop/te-pc:te-label
               /te-pc:technology:
       +--:(otn)
          +--ro otn
             +--ro tpn?       otn-tpn
             +--ro tsg?       identityref
             +--ro ts-list?   string

                Figure 2: OTN path computation tree diagram

4.  YANG Model for OTN Path Computation

   <CODE BEGINS> file "ietf-otn-path-computation@2022-07-10.yang"
   module ietf-otn-path-computation {
     yang-version 1.1;
     namespace "urn:ietf:params:xml:ns:yang:ietf-otn-path-computation";
     prefix "otn-pc";

     import ietf-te-path-computation {
       prefix "te-pc";
       revision-date "2021-09-06";
       reference
       "I-D.ietf-teas-yang-path-computation-14: Yang model
       for requesting Path Computation.";
     }

     import ietf-te {
       prefix "te";
       revision-date "2021-02-20";
       reference
         "I-D.ietf-teas-yang-te-19: A YANG Data Model for Traffic
         Engineering Tunnels and Interfaces. ";
     }

     import ietf-layer1-types {
       prefix "l1-types";
       reference
       "I-D.ietf-ccamp-layer1-types:
        A YANG Data Model for Layer 1 Types. ";
     }

     organization



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       "IETF CCAMP Working Group";
     contact
       "WG Web: <https://datatracker.ietf.org/wg/ccamp/>
        WG List:  <mailto:ccamp@ietf.org>

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

        Editor:   Italo Busi
                  <mailto:italo.busi@huawei.com>

        Editor:   Sergio Belotti
                  <mailto:sergio.belotti@nokia.com>";

     description
       "This module defines a model for requesting
       OTN Path Computation.

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

       Copyright (c) 2022 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.";

     revision "2022-09-12" {
       description
         "Initial version.";
       reference
         "RFC XXXX: A YANG Data Model for requesting Path Computation
         in an Optical Transport Network (OTN)";
       // RFC Ed.: replace XXXX with actual RFC number, update date
       // information and remove this note
     }

    /*
     * Data nodes
     */




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     /*
      * Augment TE bandwidth
      */

     augment "/te:tunnels-path-compute/te:input/te:path-compute-info/"
           + "te-pc:path-request/te-pc:te-bandwidth/te-pc:technology" {
       description
         "Augment TE bandwidth of the requested path.";
       case otn {
         uses l1-types:otn-path-bandwidth;
       }
     }

     augment "/te:tunnels-path-compute/te:input/te:path-compute-info/"
           + "te-pc:tunnel-attributes/te-pc:te-bandwidth/"
           + "te-pc:technology" {
       description
         "Augment TE bandwidth of the requested tunnel attributes.";
       case otn {
         uses l1-types:otn-path-bandwidth;
       }
     }

     augment "/te:tunnels-path-compute/te:output/"
           + "te:path-compute-result/te-pc:response/"
           + "te-pc:computed-paths-properties/"
           + "te-pc:computed-path-properties/te-pc:path-properties/"
           + "te-pc:te-bandwidth/te-pc:technology" {
       description
         "Augment TE bandwidth of the computed path properties.";
       case otn {
         uses l1-types:otn-path-bandwidth;
       }
     }

     /*
      * Augment TE label range information
      */

     augment "/te:tunnels-path-compute/te:input/te:path-compute-info/"
           + "te-pc:path-request/te-pc:path-in-segment/"
           + "te-pc:label-restrictions/te-pc:label-restriction" {
       description
         "Augment TE label range information for the ingress segment
         of the requested path.";
       uses l1-types:otn-label-range-info;
     }




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     augment "/te:tunnels-path-compute/te:input/te:path-compute-info/"
           + "te-pc:path-request/te-pc:path-out-segment/"
           + "te-pc:label-restrictions/te-pc:label-restriction" {
       description
         "Augment TE label range information for the egress segment
         of the requested path.";
       uses l1-types:otn-label-range-info;
     }

     /*
      * Augment TE label.
      */

     augment "/te:tunnels-path-compute/te:input/te:path-compute-info/"
           + "te-pc:path-request/te-pc:optimizations/te-pc:algorithm/"
           + "te-pc:metric/te-pc:optimization-metric/"
           + "te-pc:explicit-route-exclude-objects/"
           + "te-pc:route-object-exclude-object/te-pc:type/te-pc:label/"
           + "te-pc:label-hop/te-pc:te-label/te-pc:technology" {
       description
         "Augment TE label hop for the optimization of the explicit
         route objects excluded by the path computation of the requested
         path.";
       case otn {
         uses l1-types:otn-label-hop;
       }
     }

     augment "/te:tunnels-path-compute/te:input/te:path-compute-info/"
           + "te-pc:path-request/te-pc:optimizations/te-pc:algorithm/"
           + "te-pc:metric/te-pc:optimization-metric/"
           + "te-pc:explicit-route-include-objects/"
           + "te-pc:route-object-include-object/te-pc:type/te-pc:label/"
           + "te-pc:label-hop/te-pc:te-label/te-pc:technology" {
       description
         "Augment TE label hop for the optimization of the explicit
         route objects included by the path computation of the requested
         path.";
       case otn {
         uses l1-types:otn-label-hop;
       }
     }

     augment "/te:tunnels-path-compute/te:input/te:path-compute-info/"
           + "te-pc:path-request/te-pc:explicit-route-objects-always/"
           + "te-pc:route-object-exclude-always/te-pc:type/te-pc:label/"
           + "te-pc:label-hop/te-pc:te-label/te-pc:technology" {
       description



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         "Augment TE label hop for the explicit route objects always
         excluded by the path computation of the requested path.";
       case otn {
         uses l1-types:otn-label-hop;
       }
     }

     augment "/te:tunnels-path-compute/te:input/te:path-compute-info/"
           + "te-pc:path-request/te-pc:explicit-route-objects-always/"
           + "te-pc:route-object-include-exclude/te-pc:type/"
           + "te-pc:label/te-pc:label-hop/te-pc:te-label/"
           + "te-pc:technology" {
       description
         "Augment TE label hop for the explicit route objects included
         or excluded by the path computation of the requested path.";
       case otn {
         uses l1-types:otn-label-hop;
       }
     }

     augment "/te:tunnels-path-compute/te:input/te:path-compute-info/"
           + "te-pc:path-request/te-pc:path-in-segment/"
           + "te-pc:label-restrictions/te-pc:label-restriction/"
           + "te-pc:label-start/te-pc:te-label/te-pc:technology" {
       description
         "Augment TE label range start for the ingress segment
         of the requested path.";
       case otn {
         uses l1-types:otn-label-start-end;
       }
     }

     augment "/te:tunnels-path-compute/te:input/te:path-compute-info/"
           + "te-pc:path-request/te-pc:path-in-segment/"
           + "te-pc:label-restrictions/te-pc:label-restriction/"
           + "te-pc:label-end/te-pc:te-label/te-pc:technology" {
       description
         "Augment TE label range end for the ingress segment
         of the requested path.";
       case otn {
         uses l1-types:otn-label-start-end;
       }
     }

     augment "/te:tunnels-path-compute/te:input/te:path-compute-info/"
           + "te-pc:path-request/te-pc:path-in-segment/"
           + "te-pc:label-restrictions/te-pc:label-restriction/"
           + "te-pc:label-step/te-pc:technology" {



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       description
         "Augment TE label range step for the ingress segment
         of the requested path.";
       case otn {
         uses l1-types:otn-label-step;
       }
     }

     augment "/te:tunnels-path-compute/te:input/te:path-compute-info/"
           + "te-pc:path-request/te-pc:path-out-segment/"
           + "te-pc:label-restrictions/te-pc:label-restriction/"
           + "te-pc:label-start/te-pc:te-label/te-pc:technology" {
       description
         "Augment TE label range start for the egress segment
         of the requested path.";
       case otn {
         uses l1-types:otn-label-start-end;
       }
     }

     augment "/te:tunnels-path-compute/te:input/te:path-compute-info/"
           + "te-pc:path-request/te-pc:path-out-segment/"
           + "te-pc:label-restrictions/te-pc:label-restriction/"
           + "te-pc:label-end/te-pc:te-label/te-pc:technology" {
       description
         "Augment TE label range end for the egress segment
         of the requested path.";
       case otn {
         uses l1-types:otn-label-start-end;
       }
     }

     augment "/te:tunnels-path-compute/te:input/te:path-compute-info/"
           + "te-pc:path-request/te-pc:path-out-segment/"
           + "te-pc:label-restrictions/te-pc:label-restriction/"
           + "te-pc:label-step/te-pc:technology" {
       description
         "Augment TE label range end for the egress segment
         of the requested path.";
       case otn {
         uses l1-types:otn-label-step;
       }
     }

     augment "/te:tunnels-path-compute/te:input/te:path-compute-info/"
           + "te-pc:synchronization/te-pc:exclude-objects/"
           + "te-pc:excludes/te-pc:type/te-pc:label/te-pc:label-hop/"
           + "te-pc:te-label/te-pc:technology" {



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       description
         "Augment TE label hop for the explicit route objects to always
         exclude from synchronized path computation.";
       case otn {
         uses l1-types:otn-label-hop;
       }
     }

     augment "/te:tunnels-path-compute/te:output/"
           + "te:path-compute-result/te-pc:response/"
           + "te-pc:computed-paths-properties/"
           + "te-pc:computed-path-properties/te-pc:path-properties/"
           + "te-pc:path-route-objects/te-pc:path-route-object/"
           + "te-pc:type/te-pc:label/"
           + "te-pc:label-hop/te-pc:te-label/te-pc:technology" {
       description
         "Augment TE label hop for the route object of the computed
         path.";
       case otn {
         uses l1-types:otn-label-hop;
       }
     }
   }
   <CODE ENDS>

                 Figure 3: OTN path computation YANG module

5.  Manageability Considerations

   This document provides a method for requesting path computations for
   OTN tunnels.  Consideration of mechanisms to gather and collate
   information required for the path computations will be necessary.
   Furthermore, storing path computation requests and responses and
   triggering actions will also need to be carefully managed and
   secured.

   Future versions of this document will contain additional information.

6.  Security Considerations

   The YANG module defined in this document will be accessed via the
   NETCONF protocol [RFC6241] or RESTCONF protocol [RFC8040].  The
   lowest NETCONF layer is the secure transport layer, and the
   mandatory-to-implement secure transport is Secure Shell (SSH)
   [RFC6242].  The lowest RESTCONF layer is HTTPS and the mandatory-to-
   implement secure transport is TLS [RFC8446].





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   The Network Configuration Access Control Model (NACM) [RFC8341]
   provides the means to restrict access to particular NETCONF or
   RESTCONF users to a pre-configured subset of all available NETCONF or
   RESTCONF protocol operations and content.

   Some of the RPC operations defined in this YANG module may be
   considered sensitive or vulnerable in some network environments.  It
   is thus essential to control access to these operations.

   Operations defined in this document, and their sensitivities and
   possible vulnerabilities, will be discussed further in future
   versions of this document.

7.  IANA Considerations

   This document registers the following URIs in the "ns" subregistry
   within the "IETF XML registry" [RFC3688].

     URI: urn:ietf:params:xml:ns:yang:ietf-otn-path-computation
     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 [RFC7950].

     name:      ietf-otn-path-computation
     namespace: urn:ietf:params:xml:ns:yang:ietf-otn-path-computation
     prefix:    otn-pc
     reference: this document

8.  References

8.1.  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-teas-yang-path-computation]
              Busi, I., Belotti, S., de Dios, O. G., Sharma, A., and Y.
              Shi, "A YANG Data Model for requesting path computation",
              Work in Progress, Internet-Draft, draft-ietf-teas-yang-
              path-computation-26, 5 February 2026,
              <https://datatracker.ietf.org/doc/html/draft-ietf-teas-
              yang-path-computation-26>.



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   [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-44, 26
              March 2026, <https://datatracker.ietf.org/doc/html/draft-
              ietf-teas-yang-te-44>.

   [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
              DOI 10.17487/RFC3688, January 2004,
              <https://www.rfc-editor.org/rfc/rfc3688>.

   [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>.

   [RFC6242]  Wasserman, M., "Using the NETCONF Protocol over Secure
              Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
              <https://www.rfc-editor.org/rfc/rfc6242>.

   [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>.

   [RFC8040]  Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
              Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
              <https://www.rfc-editor.org/rfc/rfc8040>.

   [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>.

   [RFC8341]  Bierman, A. and M. Bjorklund, "Network Configuration
              Access Control Model", STD 91, RFC 8341,
              DOI 10.17487/RFC8341, March 2018,
              <https://www.rfc-editor.org/rfc/rfc8341>.

   [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>.

   [RFC8446]  Rescorla, E., "The Transport Layer Security (TLS) Protocol
              Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
              <https://www.rfc-editor.org/rfc/rfc8446>.

8.2.  Informative References



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   [I-D.draft-gbb-ccamp-optical-path-computation-yang]
              Busi, I., Guo, A., and S. Belotti, "YANG Data Models for
              requesting Path Computation in Optical Networks", Work in
              Progress, Internet-Draft, draft-gbb-ccamp-optical-path-
              computation-yang-02, 12 September 2022,
              <https://datatracker.ietf.org/doc/html/draft-gbb-ccamp-
              optical-path-computation-yang-02>.

   [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-20, 7 November 2024,
              <https://datatracker.ietf.org/doc/html/draft-ietf-ccamp-
              otn-topo-yang-20>.

   [I-D.ietf-teas-actn-poi-applicability]
              Peruzzini, F., Bouquier, J., Busi, I., King, D., and D.
              Ceccarelli, "Applicability of Abstraction and Control of
              Traffic Engineered Networks (ACTN) to Packet Optical
              Integration (POI)", Work in Progress, Internet-Draft,
              draft-ietf-teas-actn-poi-applicability-18, 14 March 2026,
              <https://datatracker.ietf.org/doc/html/draft-ietf-teas-
              actn-poi-applicability-18>.

Appendix A.  Change Log

   The initial YANG data model requesting path computation in optical
   networks was draft-gbb-ccamp-optical-path-computation-yang-00.  This
   document included path computation request capabilities for WSON,
   Flexi-Grid and OTN technologies.  However, it was proposed at IETF
   113 (March 25, 2022) to split the initial document into separate
   documents for WDM (WSON and Flexi-Grid) and OTN technologies, as each
   technology may be developed and implemented separately.

   The WDM technology capabilities were kept in
   [I-D.draft-gbb-ccamp-optical-path-computation-yang], and the OTN
   capabilities were moved into this document.

   Editors note, please remove this appendix before publication.

Acknowledgments

   The authors of this document would like to thank the authors of
   [I-D.ietf-teas-actn-poi-applicability] for having identified the gap
   and requirements to trigger this work.

   This document was prepared using kramdown.



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Contributors

   Daniel King
   Old Dog Consulting
   Email: daniel@olddog.co.uk


Authors' Addresses

   Italo Busi
   Huawei Technologies
   Email: italo.busi@huawei.com


   Aihua Guo
   Futurewei Technologies
   Email: aihuaguo.ietf@gmail.com


   Sergio Belotti
   Nokia
   Email: sergio.belotti@nokia.com





























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