TEAS Working Group T. Saad Internet-Draft R. Gandhi Intended status: Standards Track Cisco Systems Inc Expires: 28 August 2026 X. Liu Alef Edge V. P. Beeram Juniper Networks I. Bryskin Individual 24 February 2026 A YANG Data Model for Traffic Engineering Tunnels, Label Switched Paths, and Interfaces draft-ietf-teas-yang-te-42 Abstract This document defines a YANG data model for the provisioning and management of Traffic Engineering (TE) tunnels, Label Switched Paths (LSPs), and interfaces. The model covers data that is independent of any technology or dataplane encapsulation and is divided into two YANG modules that cover device-specific, and device independent data. This model covers data for configuration, operational state, remote procedural calls, and event notifications. 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 28 August 2026. Copyright Notice Copyright (c) 2026 IETF Trust and the persons identified as the document authors. All rights reserved. Saad, et al. Expires 28 August 2026 [Page 1] Internet-Draft TE YANG Data Model February 2026 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 and restrictions with respect to this document. Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terms and Conventions . . . . . . . . . . . . . . . . . . . . 3 2.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 2.2. Prefixes in Data Node Names . . . . . . . . . . . . . . . 4 2.3. Model Tree Diagrams . . . . . . . . . . . . . . . . . . . 4 3. Design Considerations . . . . . . . . . . . . . . . . . . . . 4 4. Model Overview . . . . . . . . . . . . . . . . . . . . . . . 5 4.1. Module Relationship . . . . . . . . . . . . . . . . . . . 6 5. TE YANG Model . . . . . . . . . . . . . . . . . . . . . . . . 7 5.1. Relationship Between TE Tunnel, LSP, and Path . . . . . . 7 5.2. Module Structure . . . . . . . . . . . . . . . . . . . . 8 5.2.1. TE Globals . . . . . . . . . . . . . . . . . . . . . 9 5.2.2. TE Tunnels . . . . . . . . . . . . . . . . . . . . . 13 5.2.3. TE LSPs . . . . . . . . . . . . . . . . . . . . . . . 23 5.3. Tree Diagram . . . . . . . . . . . . . . . . . . . . . . 23 5.4. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 25 6. TE Device YANG Model . . . . . . . . . . . . . . . . . . . . 59 6.1. Module Structure . . . . . . . . . . . . . . . . . . . . 60 6.1.1. TE Device Globals, Tunnels and LSPs . . . . . . . . . 60 6.1.2. TE Device Interfaces . . . . . . . . . . . . . . . . 62 6.2. Tree Diagram . . . . . . . . . . . . . . . . . . . . . . 67 6.3. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 69 7. Notifications . . . . . . . . . . . . . . . . . . . . . . . . 82 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 82 9. Security Considerations . . . . . . . . . . . . . . . . . . . 83 10. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 84 11. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 85 12. References . . . . . . . . . . . . . . . . . . . . . . . . . 85 12.1. Normative References . . . . . . . . . . . . . . . . . . 85 12.2. Informative References . . . . . . . . . . . . . . . . . 89 Appendix A. Data Tree Examples . . . . . . . . . . . . . . . . . 90 A.1. Basic Tunnel Setup . . . . . . . . . . . . . . . . . . . 90 A.2. Global Named Path Constraints . . . . . . . . . . . . . . 91 A.3. Tunnel with Global Path Constraint . . . . . . . . . . . 92 A.4. Tunnel with Per-tunnel Path Constraint . . . . . . . . . 93 A.5. Tunnel State . . . . . . . . . . . . . . . . . . . . . . 94 A.6. Example TE Tunnel with Primary and Secondary Paths . . . 96 Saad, et al. Expires 28 August 2026 [Page 2] Internet-Draft TE YANG Data Model February 2026 A.7. Example Multi-domain TE Tunnel with Primary and Secondary Paths . . . . . . . . . . . . . . . . . . . . . . . . . . 106 Appendix B. Full Model Tree Diagram . . . . . . . . . . . . . . 111 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 117 1. Introduction This document defines a YANG data model intended for the provisioning and management of point-to-point Traffic Engineering (TE) tunnels, Label Switched Paths (LSPs), and interfaces. The modeling of point- to-multipoint TE Tunnels [RFC4875] and Segment-Routing (SR) Policies [RFC9256] falls outside the scope of this document. The data model described herein is divided into two YANG modules. The 'ietf-te' module contains generic, device-independent data, and the 'ietf-te-device' module addresses device-specific data. This document outlines the high-level relationships between the YANG modules it defines and other external protocol YANG modules. The TE YANG data model intentionally excludes data specific to any signaling protocol, such as RSVP-TE ([RFC3209], [RFC3473]), or Segment-Routing TE (SR-TE) [RFC9256] with the expectation that such technology models will be defined in separate documents and will augment the generic TE model as needed. 2. Terms and Conventions 2.1. Terminology The following terms are defined in [RFC6241] and are used in this specification: * client * configuration data * state data This document also makes use of the following terminology introduced in the YANG Data Modeling Language [RFC7950]: * augment * data model * data node Saad, et al. Expires 28 August 2026 [Page 3] Internet-Draft TE YANG Data Model February 2026 2.2. Prefixes 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 | +============+===============+======================================+ | yang | ietf-yang- | [RFC9911] | | | types | | +------------+---------------+--------------------------------------+ | inet | ietf-inet- | [RFC9911] | | | types | | +------------+---------------+--------------------------------------+ | rt- | ietf-routing- | [RFC8294] | | types | types | | +------------+---------------+--------------------------------------+ | te- | ietf-te-types | [I-D.draft-ietf-teas-rfc8776-update] | | types | | | +------------+---------------+--------------------------------------+ | te- | ietf-te- | [I-D.draft-ietf-teas-rfc8776-update] | | packet- | packet-types | | | types | | | +------------+---------------+--------------------------------------+ | te | ietf-te | this document | +------------+---------------+--------------------------------------+ | te-dev | ietf-te- | this document | | | device | | +------------+---------------+--------------------------------------+ Table 1: Prefixes and corresponding YANG modules 2.3. Model Tree Diagrams The tree diagrams extracted from the modules defined in this document are given in subsequent sections as per the syntax defined in [RFC8340]. 3. Design Considerations This document describes a generic TE YANG data model that is independent of any dataplane technology. One of the design objectives is to allow specific data plane technology models to reuse the TE generic data model and possibly augment it with technology- specific data. Saad, et al. Expires 28 August 2026 [Page 4] Internet-Draft TE YANG Data Model February 2026 The elements of the generic TE YANG data model, including TE Tunnels, LSPs, and interfaces have leafs that identify the technology layer where they reside. For example, the LSP encoding type can identify the technology associated with a TE Tunnel or LSP. Also, the generic TE YANG data model does not cover signaling protocol data. The signaling protocols used to instantiate TE LSPs are outside the scope of this document and expected to be covered by augmentations defined in other documents. The following other design considerations are taken into account with respect to data organization: * The device independent TE data is defined in the 'ietf-te' module, and can be used to manage data off a device, such as a TE controller. When the model is used to manage a specific device, the model contains the TE Tunnels originating from the specific device. When the model is used to manage a TE controller, the 'tunnel' list contains all TE Tunnels and TE tunnel segments originating from devices that the TE controller manages. * The device-specific TE data is defined in the 'ietf-te-device' module. * Minimal elements in the model are designated as "mandatory" to allow freedom to vendors to adapt the data model to their specific product implementation. * Suitable defaults are specified for all configurable elements. * Where TE functions or features might be optional within the deployed TE network, the model declares them as optional. 4. Model Overview The data model defined in this document cover the core TE features that are commonly supported by different vendor implementations. The support of extended or vendor specific TE features is expected to either be in augmentations, or deviations to this model that are defined in separate documents. Saad, et al. Expires 28 August 2026 [Page 5] Internet-Draft TE YANG Data Model February 2026 4.1. Module Relationship The generic TE YANG data model, defined in the 'ietf-te' YANG module, provides device-independent building blocks that are agnostic of specific technologies or control plane instances. The TE device YANG data model, defined in the 'ietf-te-device' YANG module, augments the 'ietf-te' YANG module as illustrated in Figure 1 by including device- specific data such as TE interface attributes and local TE node timers. The TE data models for specific instances of data plane technology and signaling protocols are outside the scope of this document. They could be defined in separate YANG modules that augment the generic TE YANG data model. TE generic +---------+ module | ietf-te |o-------------+ +---------+ \ o o \ | \ \ | \ TE device module \ | +----------------+ \ | | ietf-te-device | \ | +----------------+ \ | o \ | | \ | | \ +---------------+ +---------------+ RSVP-TE module | ietf-rsvp-te^ |o | ietf-te-mpls^ | +---------------+ \ +---------------+ | \ | \ | \ | \ | \ o +-------------------+ +------------+ | ietf-rsvp-otn-te^ | RSVP module | ietf-rsvp^ | +-------------------+ +------------+ RSVP-TE with OTN extensions X---oY indicates that module X augments module Y ^ indicates a module defined in other documents Figure 1: Relationship of TE modules with signaling protocol modules Saad, et al. Expires 28 August 2026 [Page 6] Internet-Draft TE YANG Data Model February 2026 5. TE YANG Model The generic TE YANG data model defined in the 'ietf-te' module supports the management and operation of a TE network. This includes creating, modifying, and retrieving information about TE Tunnels, LSPs, and interfaces and their associated attributes (e.g. Administrative-Groups (AGs), Shared Risk Link Groups (SRLGs), etc.). A full tree diagram of the TE YANG data model is shown in Appendix B. 5.1. Relationship Between TE Tunnel, LSP, and Path The TE YANG model is built around several core constructs: TE tunnel, TE path, and LSP. These concepts are central to the model's structure and functionality. TE Tunnel: In this context, a TE tunnel represents a logical construct that defines an engineered connectivity service between two endpoints in the network, typically an ingress (source) and an egress (destination). A tunnel is characterized by its attributes (such as name, encoding, and constraints) and serves as the container for the forwarding resources used to realize the desired connectivity. TE Path: A path refers to a specific sequence of nodes and links through the network that traffic will follow to traverse the TE tunnel from source to destination. A TE tunnel may have one or more associated TE paths, such as a primary TE path (the preferred path) and secondary TE paths (used for protection or restoration). Each path specifies the constraints, preferences, and optimization criteria that guide its computation and selection. LSP: An LSP is an actual, instantiated connection in the data plane that follows a computed TE path through the network. It is the result of signaling protocols (such as RSVP-TE or Segment Routing) setting up forwarding state along the TE path, enabling the tunnel to carry traffic. The relationship among these concepts is as follows: Saad, et al. Expires 28 August 2026 [Page 7] Internet-Draft TE YANG Data Model February 2026 A TE tunnel is the high-level logical object that defines the desired connectivity and its properties. Each TE tunnel can have one or more TE paths, which define candidate or active routes through the network that may be used to realize the tunnel's connectivity, subject to certain constraints and preferences. For each TE path selected for use, one or more LSPs are instantiated in the network to realize the forwarding state necessary to carry traffic along the specified TE path. In summary, a TE tunnel defines the service, a TE path defines how to achieve the service, and an LSP is the instantiated mechanism that actually provides the service in the forwarding plane. 5.2. Module Structure The 'te' container is the top level container in the 'ietf-te' module. The presence of the 'te' container enables TE function system-wide. Further descriptions of containers that exist under the 'te' top level container are provided in the following sections. The three containers grouped under the 'te' container are shown in Figure 2 and described below. globals: The 'globals' container maintains the set of global TE attributes that can be applicable to TE Tunnels and interfaces. Refer to Section 5.2.1 for further details. tunnels: The 'tunnels' container includes the list of TE Tunnels that are instantiated. Refer to Section 5.2.2 for further details on the properties of a TE Tunnel. lsps: The 'lsps' container includes the list of TE LSPs that are instantiated for TE Tunnels. Refer to Section 5.2.3 for further details on the properties of a TE LSP. The model also contains two Remote Procedure Calls (RPCs) as shown in Appendix B and described below. tunnels-path-compute: Saad, et al. Expires 28 August 2026 [Page 8] Internet-Draft TE YANG Data Model February 2026 An RPC to request path computation for a specific TE Tunnel. The RPC allows requesting path computation using atomic and stateless operation. A tunnel may also be configured in 'compute-only' mode to provide stateful path updates - see Section 5.2.2 for further details. tunnels-action: An RPC to request a specific action (e.g. reoptimize, or tear-and- setup) to be taken on a specific tunnel or all tunnels. module: ietf-te +--rw te! +--rw globals | ... +--rw tunnels | ... +--ro lsps ... rpcs: +---x tunnels-path-compute | +---w input | | ... | +--ro output | ... +---x tunnels-actions +---w input | ... +--ro output ... Figure 2: TE Tunnel model high-level YANG tree view 5.2.1. TE Globals The 'globals' container covers properties that control a TE feature's behavior system-wide, and its respective state as shown in Figure 3 and described in the text that follows. Saad, et al. Expires 28 August 2026 [Page 9] Internet-Draft TE YANG Data Model February 2026 +--rw globals | +--rw named-admin-groups | | +--rw named-admin-group* [name] | | ... | +--rw named-srlgs | | +--rw named-srlg* [name] | | ... | +--rw named-path-constraints | +--rw named-path-constraint* [name] Figure 3: TE globals YANG subtree high-level structure named-admin-groups: A YANG container for the list of named (extended) administrative groups that may be applied to TE links. named-srlgs: A YANG container for the list of named SRLGs that may be applied to TE links. named-path-constraints: A YANG container for a list of named path constraints. Each named path constraint is composed of a set of constraints that can be applied during path computation. A named path constraint can be applied to multiple TE Tunnels. Path constraints may also be specified directly under the TE Tunnel. The path constraints specified under the TE Tunnel take precedence over the path constraints derived from the referenced named path constraint. A named path constraint entry can be formed of the path constraints shown in Figure 4: Saad, et al. Expires 28 August 2026 [Page 10] Internet-Draft TE YANG Data Model February 2026 | +--rw named-path-constraints | +--rw named-path-constraint* [name] | {te-types:named-path-constraints}? | +--rw name string | +--rw te-bandwidth | | ... | +--rw link-protection? identityref | +--rw setup-priority? uint8 | +--rw hold-priority? uint8 | +--rw signaling-type? identityref | +--rw path-metric-bounds | | ... | +--rw path-affinities-values | | ... | +--rw path-affinity-names | | ... | +--rw path-srlgs-lists | | ... | +--rw path-srlgs-names | | ... | +--rw disjointness? | | te-path-disjointness | +--rw explicit-route-objects | | ... | +--rw path-in-segment! | | ... | +--rw path-out-segment! | ... Figure 4: Named path constraints YANG subtree - name: A YANG leaf that holds the named path constraint entry. This is unique in the list and used as a key. - te-bandwidth: A YANG container that holds the technology- agnostic TE bandwidth constraint. - link-protection: A YANG leaf that holds the link protection type constraint required for the links to be included in the computed path. - setup/hold priority: YANG leafs that hold the LSP setup and hold admission priority as defined in [RFC3209]. - signaling-type: A YANG leaf that holds the LSP setup type, such as RSVP-TE or SR. Saad, et al. Expires 28 August 2026 [Page 11] Internet-Draft TE YANG Data Model February 2026 - path-metric-bounds: A YANG container that holds the set of metric bounds applicable on the computed TE tunnel path. - path-affinities-values: A YANG container that holds the set of affinity values and mask to be used during path computation. - path-affinity-names: A YANG container that holds the set of named affinity constraints and corresponding inclusion or exclusion instructions for each to be used during path computation. - path-srlgs-lists: A YANG container that holds the set of SRLG values and corresponding inclusion or exclusion instructions to be used during path computation. - path-srlgs-names: A YANG container that holds the set of named SRLG constraints and corresponding inclusion or exclusion instructions for each to be used during path computation. - disjointness: The level of resource disjointness constraint that the secondary path of a TE tunnel has to adhere to. - explicit-route-objects: A YANG container that holds path constraints in the form of route entries present in the following two lists: o 'route-object-exclude-always': a list of route entries that are always excluded from the path computation. The exclusion of a route entry in this list during path computation is not order sensitive. The route entries in this list have a 'strict' hop-type as described in [RFC4874] section 3.1. o 'route-object-include-exclude': a list of route entries to include or exclude for the path computation. For route entries in this list that are to be excluded, the hop-type is only allowed to be 'strict' as described in [RFC4874] section 3.1. The constraint type (include or exclude) is specified with each route entry. The path computation considers route entry constraints in the order they appear in this list. Once a route entry constraint is consumed from this list, it is not considered any further in the computation of the TE path. The 'route-object-include-exclude' is used to configure constraints on which route objects (e.g., nodes, links) are included or excluded in the path computation. The interpretation of an empty 'route-object-include- Saad, et al. Expires 28 August 2026 [Page 12] Internet-Draft TE YANG Data Model February 2026 exclude' list depends on the TE Tunnel (end-to-end or Tunnel Segment) and on the specific path, according to the following rules: 1. An empty 'route-object-include-exclude' list for the primary path of an end-to-end TE Tunnel indicates that there are no route objects to be included or excluded in the path computation. 2. An empty 'route-object-include-exclude' list for the primary path of a TE Tunnel Segment indicates that no primary LSP is required for that TE Tunnel Segment. 3. An empty 'route-object-include-exclude' list for a reverse path means it always follows the forward path (i.e., the TE Tunnel is co-routed). When the 'route- object-include-exclude' list is not empty, the reverse path is routed independently of the forward path. 4. An empty 'route-object-include-exclude' list for the secondary (forward) path of a TE Tunnel segment indicates that the secondary path has the same endpoints as the primary path. - path-in-segment: A YANG container that contains a list of label restrictions that have to be taken into consideration when stitching to another tunnel segment such as at a domain boundary. The TE tunnel segment in this case is being stitched to the upstream TE tunnel segment. - path-out-segment: A YANG container that contains a list of label restrictions that have to be taken into consideration when stitching to another tunnel segment such as at a domain boundary. The TE tunnel segment in this case is being stitched to the downstream TE tunnel segment. 5.2.2. TE Tunnels The 'tunnels' container holds the list of TE Tunnels that are provisioned on ingress router devices in the network as shown in Figure 5. module: ietf-te +--rw te +--rw tunnels +--rw tunnel* [name] +--rw name string +--rw alias? string Saad, et al. Expires 28 August 2026 [Page 13] Internet-Draft TE YANG Data Model February 2026 +--rw identifier? uint32 +--rw color? uint32 +--rw description? string +--rw admin-state? identityref +--ro operational-state? identityref +--rw encoding? identityref +--rw switching-type? identityref +--rw source | ... +--rw destination | ... +--rw bidirectional? boolean +--rw controller | ... +--rw reoptimize-timer? uint16 +--rw association-objects | ... +--rw protection | ... +--rw restoration | ... +--rw network-id? nw:network-id +--rw te-topology-identifier | ... +--rw te-bandwidth | ... +--rw link-protection? identityref +--rw setup-priority? uint8 +--rw hold-priority? uint8 +--rw signaling-type? identityref +--rw hierarchy | ... +--rw primary-paths | ... +--rw secondary-paths | ... +--rw secondary-reverse-paths | ... +---x tunnel-action | ... +---x protection-external-commands ... Figure 5: TE Tunnel YANG subtree structure Saad, et al. Expires 28 August 2026 [Page 14] Internet-Draft TE YANG Data Model February 2026 When the model is used to manage a specific device, the 'tunnel' list contains the TE Tunnels originating from the specific device. When the model is used to manage a TE controller, the 'tunnel' list contains all TE Tunnels and TE tunnel segments originating from devices that the TE controller manages. The TE Tunnel model allows the configuration and management of the following TE tunnel objects: TE Tunnel: A YANG container of one or more TE LSPs established between the source and destination TE Tunnel termination points. TE Path: An engineered path that once instantiated in the forwarding plane can be used to forward traffic from the source to the destination TE Tunnel termination points. TE LSP: A TE LSP is a connection-oriented service established over a TE Path and that allows the delivery of traffic between the TE Tunnel source and destination termination points. TE Tunnel Segment: A segment of a TE Tunnel that is stitched with other segments in order to provision an end-to-end tunnel. The TE Tunnel has a number of attributes that are set directly under the tunnel (as shown in Figure 5). The main attributes of a TE Tunnel are described below: name: A YANG leaf that holds the name of a TE Tunnel. The name of the TE Tunnel uniquely identifies the tunnel within the TE tunnel list. The name of the TE Tunnel can be formatted as a Uniform Resource Indicator (URI) by including the namespace to ensure uniqueness of the name among all the TE Tunnels present on devices and controllers. The configured TE Tunnels can be reported with the name of the device embedded within the TE Tunnel name. For TE Tunnels initiated by the controller, the controller is responsible to ensure that TE Tunnel names are unique. alias: Saad, et al. Expires 28 August 2026 [Page 15] Internet-Draft TE YANG Data Model February 2026 A YANG leaf that holds an alternate name to the TE tunnel. Unlike the TE tunnel name, the alias can be modified at any time during the lifetime of the TE tunnel. identifier: A YANG leaf that holds an identifier of the tunnel. This identifier is unique among tunnels originated from the same ingress device. color: A YANG leaf that holds the color associated with the TE tunnel. The color is used to map or steer services that carry matching color onto the TE tunnel as described in [RFC9012]. admin-state: A YANG leaf that holds the tunnel administrative state. operational-state: A YANG leaf that holds the tunnel operational state. encoding/switching: The 'encoding' and 'switching-type' are YANG leafs that define the specific technology in which the tunnel operates in as described in [RFC3945]. source/destination: YANG containers that hold the tunnel source and destination node endpoint identities, including: - te-node-id: A YANG leaf that holds the TE node identifier (as defined in [I-D.draft-ietf-teas-rfc8776-update]) of the source or destination of the TE Tunnel. - node-id: A YANG leaf that holds the node identifier (as defined in [RFC8345]) of the source or destination of the TE Tunnel. - tunnel-tp-id: A YANG leaf that holds the identifier of the source or destination of the TE Tunnel Termination Points (TTPs) as defined in [RFC8795]. The TTP identifiers are optional on nodes that have a single TTP per node. For example, TTP identifiers are optional for packet (IP/MPLS) routers. Saad, et al. Expires 28 August 2026 [Page 16] Internet-Draft TE YANG Data Model February 2026 bidirectional: A YANG leaf that when present indicates the LSP of a TE Tunnel is bidirectional as defined in [rfc3473]. controller: A YANG container that holds tunnel data relevant to an optional external TE controller that may initiate or control a tunnel. This target node may be augmented by external modules, for example, to add data for Path Computation Element Protocol (PCEP) initiated and/or delegated tunnels. reoptimize-timer: A YANG leaf to set the interval period for tunnel reoptimization. association-objects: A YANG container that holds the set of associations of the TE Tunnel to other TE Tunnels. Associations at the TE Tunnel level apply to all paths of the TE Tunnel. The TE tunnel associations can be overridden by associations configured directly under the TE Tunnel path. protection: A YANG container that holds the TE Tunnel protection properties. restoration: A YANG container that holds the TE Tunnel restoration properties. te-topology-identifier: A YANG container that holds the topology identifier associated with the topology where paths for the TE tunnel are computed as defined in [RFC8795]. network-id: A YANG leaf that can optionally be used to identify the network topology where paths for the TE tunnel are computed as defined in [RFC8345]. hierarchy: Saad, et al. Expires 28 August 2026 [Page 17] Internet-Draft TE YANG Data Model February 2026 A YANG container that holds hierarchy related properties of the TE Tunnel. A TE LSP can be set up in MPLS or Generalized MPLS (GMPLS) networks to be used as a TE link to carry traffic in other (client) networks [RFC6107]. In this case, the model introduces the TE Tunnel hierarchical link endpoint parameters to identify the specific link in the client layer that the underlying TE Tunnel is associated with. The hierarchy container includes the following: - dependency-tunnels: A hierarchical set of TE Tunnels either provisioned or to be provisioned in the immediate lower layer, upon which the current TE Tunnel relies for multi-layer path computation. A dependency TE Tunnel is provisioned if it has been selected by path computation to support at least one client-layer TE Tunnel. When a dependency TE Tunnel is provisioned, it makes the TE link operational in the client layer's network topology, enabling the provisioning of TE Tunnels in the client layer. - hierarchical-link: A YANG container that holds the identity of the hierarchical link (in the client layer) that is supported by this TE Tunnel. The endpoints of the hierarchical link are defined by TE tunnel source and destination node endpoints. The hierarchical link can be identified by its source and destination link termination point identifiers. primary-paths: A YANG container that holds the list of primary paths. A primary path is identified by 'name'. A primary path is selected from the list to instantiate a primary forwarding LSP for the tunnel. The list of primary paths is visited by order of preference. A primary path has the following attributes: - primary-reverse-path: A YANG container that holds properties of the primary reverse path. The reverse path is applicable to bidirectional TE Tunnels. - candidate-secondary-paths: A YANG container that holds a list of candidate secondary paths which may be used for the primary path to support path protection. The candidate secondary paths reference paths from the tunnel secondary paths list. The preference of the secondary paths is specified within the list and dictates the order of visiting the secondary path from the list. The attributes of a secondary path can be defined separately from the primary path. The attributes of a secondary path will be inherited from the associated 'active' primary when not explicitly defined for the secondary path. Saad, et al. Expires 28 August 2026 [Page 18] Internet-Draft TE YANG Data Model February 2026 secondary-paths: A YANG container that holds the set of secondary paths. A secondary path is identified by 'name'. A secondary path can be referenced from the TE Tunnel's 'candidate-secondary-path' list. secondary-reverse-paths: A YANG container that holds the set of secondary reverse paths. A secondary reverse path is identified by 'name'. A secondary reverse path can be referenced from the TE Tunnel's 'candidate- secondary-reverse-paths' list. A secondary reverse path is modeled with the same data attributes as those of the primary path. The following set of common path attributes are shared for primary (forward and reverse) and secondary paths: path-computation-method: A YANG leaf that specifies the method used for computing the TE path. path-computation-server: A YANG container that holds the path computation server properties when the path is externally queried. compute-only: A path of a TE Tunnel is, by default, provisioned so that it can be instantiated in the forwarding plane so that it can carry traffic. In some cases, a TE path may be configured only for the purpose of computing a path and reporting it without the need to instantiate the LSP or commit any resources. In such a case, the path is configured in 'compute-only' mode to distinguish it from the default behavior. A 'compute-only' path is configured as usual with the associated per-path constraints and properties on a device or TE controller. The device or TE controller computes the feasible paths subject to configured constraints. A client may query the 'compute-only' computed path properties 'on-demand', or alternatively, can subscribe to be notified of computed paths and whenever the path properties change. use-path-computation: A YANG leaf that indicates whether or not path computation is to be used for a specified path. Saad, et al. Expires 28 August 2026 [Page 19] Internet-Draft TE YANG Data Model February 2026 lockdown: A YANG leaf that when set indicates the existing path should not be globally repaired or reoptimized. path-scope: A YANG leaf that specifies whether the path is a segment or an end-to-end path. preference: A YANG leaf that specifies the preference for the path, used to choose between paths in a list. The lower the number, the higher the preference. Paths with the same preference are treated as equal and other methods are used to choose between them. k-requested-paths: A YANG leaf that specifies the number of k-shortest paths requested from the path computation server, which are returned in order based on their computed optimization objective costs. association-objects: A YANG container that holds a list of tunnel association properties. optimizations: A YANG container that holds the optimization objectives that path computation will use to select a path. named-path-constraint: A YANG leafref that references an entry from the global list of named path constraints. te-bandwidth: A YANG container that holds the path bandwidth (see [I-D.draft-ietf-teas-rfc8776-update]). link-protection: A YANG leaf that specifies the link protection type required for the links to be included in the computed path (see [I-D.draft-ietf-teas-rfc8776-update]). Saad, et al. Expires 28 August 2026 [Page 20] Internet-Draft TE YANG Data Model February 2026 setup/hold-priority: see description provided in Section 5.2.1. These values override those provided in the referenced named-path-constraint. signaling-type: see description provided in Section 5.2.1. This value overrides the provided one in the referenced named-path-constraint. path-metric-bounds: see description provided in Section 5.2.1. These values override those provided in the referenced named-path-constraint. path-affinities-values: see description provided in Section 5.2.1. These values override those provided in the referenced named-path-constraint. path-affinity-names: see description provided in Section 5.2.1. These values override those provided in the referenced named-path-constraint. path-srlgs-lists: see description provided in Section 5.2.1. These values override those provided in the referenced named-path-constraint. path-srlgs-names: see description provided in Section 5.2.1. These values override those provided in the referenced named-path-constraint. disjointness: see description provided in Section 5.2.1. These values override those provided in the referenced named-path-constraint. explicit-route-objects: see description provided in Section 5.2.1. These values override those provided in the referenced named-path-constraint. path-in-segment: Saad, et al. Expires 28 August 2026 [Page 21] Internet-Draft TE YANG Data Model February 2026 see description provided in Section 5.2.1. These values override those provided in the referenced named-path-constraint. path-out-segment: see description provided in Section 5.2.1. These values override those provided in the referenced named-path-constraint. computed-paths-properties: A YANG container that holds properties for the list of computed paths. computed-path-error-infos: A YANG container that holds the list of path computation error information. The TE system populates entries in this list whenever an error is encountered during the computation of the TE path. path-compute-info: A YANG grouping that contains leafs representing the path attributes that are passed to the TE path computation engine to be considered during the path computation. This includes: - path constraints, - path optimization objectives, and - path associations Note, unless overridden under a specific path of the TE tunnel, the TE tunnel's primary path constraints, optimization objectives, and associations are inherited by the primary reverse path, secondary path and secondary reverse path. lsps: A YANG container that holds a list of LSPs that have been instantiated for this specific path. In addition to the path common attributes, the primary path has the following attributes that are not present in the secondary path: * Only the primary path contains the list of 'candidate-secondary- paths' that can protect the primary path. Saad, et al. Expires 28 August 2026 [Page 22] Internet-Draft TE YANG Data Model February 2026 * Only the primary path can contain a primary-reverse-path associated with the primary path (and its associated list of 'candidate-secondary-reverse-path'). lsp-provisioning-error-infos: A YANG container that holds the list of LSP provisioning error information. The TE system populates entries in this list whenever an error is encountered during the LSP provisioning. 5.2.3. TE LSPs The 'lsps' container includes the set of TE LSPs that have been instantiated. A TE LSP is identified by a 3-tuple ('tunnel-name', 'lsp-id', 'node'). When the model is used to manage a specific device, the 'lsps' list contains all TE LSPs that traverse the device (including ingressing, transiting and egressing the device). When the model is used to manage a TE controller, the 'lsps' list contains the TE LSPs on devices managed by the controller that act as ingress, and may optionally include TE LSPs on devices managed by the controller that act as transit or egress role. 5.3. Tree Diagram Figure 6 shows the tree diagram of depth=4 for the generic TE YANG data model defined in the 'ietf-te' module. The full tree diagram is shown in Appendix B. module: ietf-te +--rw te +--rw enable? boolean +--rw globals | +--rw named-admin-groups | | +--rw named-admin-group* [name] | | {te-types:extended-admin-groups, | | te-types:named-extended-admin-groups}? | | ... | +--rw named-srlgs | | +--rw named-srlg* [name] {te-types:named-srlg-groups}? | | ... | +--rw named-path-constraints | +--rw named-path-constraint* [name] | {te-types:named-path-constraints}? | ... +--rw tunnels Saad, et al. Expires 28 August 2026 [Page 23] Internet-Draft TE YANG Data Model February 2026 | +--rw tunnel* [name] | +--rw name string | +--rw alias? string | +--rw identifier? uint32 | +--rw color? uint32 | +--rw description? string | +--rw admin-state? identityref | +--ro operational-state? identityref | +--rw encoding? identityref | +--rw switching-type? identityref | +--rw source | | ... | +--rw destination | | ... | +--rw bidirectional? boolean | +--rw controller | | ... | +--rw reoptimize-timer? uint16 | +--rw association-objects | | ... | +--rw protection | | ... | +--rw restoration | | ... | +--rw network-id? nw:network-id | +--rw te-topology-identifier | | ... | +--rw te-bandwidth | | ... | +--rw link-protection? identityref | +--rw setup-priority? uint8 | +--rw hold-priority? uint8 | +--rw signaling-type? identityref | +--rw hierarchy | | ... | +--rw primary-paths | | ... | +--rw secondary-paths | | ... | +--rw secondary-reverse-paths | | ... | +---x tunnel-action | | ... | +---x protection-external-commands | ... +--ro lsps +--ro lsp* [tunnel-name lsp-id node] +--ro tunnel-name string Saad, et al. Expires 28 August 2026 [Page 24] Internet-Draft TE YANG Data Model February 2026 +--ro lsp-id uint16 +--ro node | te-types:te-node-id +--ro source? | te-types:te-node-id +--ro destination? | te-types:te-node-id +--ro tunnel-id? uint16 +--ro extended-tunnel-id? | yang:dotted-quad +--ro operational-state? identityref +--ro signaling-type? identityref +--ro origin-type? enumeration +--ro lsp-resource-status? enumeration +--ro lockout-of-normal? boolean +--ro freeze? boolean +--ro lsp-protection-role? enumeration +--ro lsp-protection-state? identityref +--ro ingress-node-id? | te-types:te-node-id +--ro egress-node-id? | te-types:te-node-id +--ro lsp-actual-route-information ... rpcs: +---x tunnels-path-compute | +---w input | | +---w path-compute-info | +--ro output | +--ro path-compute-result +---x tunnels-actions +---w input | +---w tunnel-info | | +---w (filter-type) | | ... | +---w action-info | +---w action? identityref | +---w disruptive? empty +--ro output +--ro action-result? identityref Figure 6: Tree diagram of depth-4 of TE Tunnel YANG data model 5.4. YANG Module The generic TE YANG module 'ietf-te' imports the following modules: Saad, et al. Expires 28 August 2026 [Page 25] Internet-Draft TE YANG Data Model February 2026 * ietf-te-types defined in [I-D.draft-ietf-teas-rfc8776-update] * ietf-yang-types and ietf-inet-types defined in [RFC9911] * ietf-network and ietf-network-topology defined in [RFC8345] This module references the following documents: [RFC4206], [RFC4427], [RFC4872], [RFC3209], [RFC6780], [RFC7471], [RFC9012], [RFC8570], [RFC8232], [RFC7271], [RFC8234], [RFC4655], [RFC8231], [RFC7308], [RFC8345], [RFC9256], and [ITU_G.808.1]. file "ietf-te@2026-02-24.yang" yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-te"; prefix te; /* Import TE generic types */ import ietf-te-types { prefix te-types; reference "draft-ietf-teas-rfc8776-update: Common YANG Data Types for Traffic Engineering."; } import ietf-yang-types { prefix yang; reference "RFC 9911: Common YANG Data Types."; } import ietf-network { prefix "nw"; reference "RFC 8345: A YANG Data Model for Network Topologies"; } import ietf-network-topology { prefix "nt"; reference "RFC 8345: A YANG Data Model for Network Topologies"; } organization "IETF Traffic Engineering Architecture and Signaling (TEAS) Working Group."; contact "WG Web: WG List: Saad, et al. Expires 28 August 2026 [Page 26] Internet-Draft TE YANG Data Model February 2026 Editor: Tarek Saad Editor: Rakesh Gandhi Editor: Vishnu Pavan Beeram Editor: Xufeng Liu Editor: Igor Bryskin "; description "YANG data module for TE configuration, state, and RPCs. Copyright (c) 2025 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). All revisions of IETF and IANA published modules can be found at the "YANG Parameters" registry group: https://www.iana.org/assignments/yang-parameters. 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 2025-02-24 { description "Initial revision for the TE generic YANG module."; reference "RFCXXXX: A YANG Data Model for Traffic Engineering Tunnels, Label Switched Paths, and Interfaces."; } Saad, et al. Expires 28 August 2026 [Page 27] Internet-Draft TE YANG Data Model February 2026 typedef tunnel-ref { type leafref { path "/te:te/te:tunnels/te:tunnel/te:name"; require-instance false; } description "This type is used by data models that need to reference a configured TE tunnel."; } /** * TE tunnel generic groupings */ grouping path-common-properties { description "Common path attributes."; leaf name { type string; description "TE path name."; } leaf symbolic-name { type string; description "The symbolic path name is a human-readable string that identifies an LSP in the network. The symbolic path name must remain constant throughout an LSP's lifetime."; reference "RFC 8231: Path Computation Element Communication Protocol (PCEP) Extensions for Stateful PCE, Section 7.3.2"; } leaf path-computation-method { type identityref { base te-types:path-computation-method; } default "te-types:path-locally-computed"; description "The method used for computing the path, either locally computed, queried from a server or not computed at all (explicitly configured)."; } container path-computation-server { when "derived-from-or-self(../path-computation-method, " + "'te-types:path-externally-queried')" { description "The IP address or the TE identifier of the external Saad, et al. Expires 28 August 2026 [Page 28] Internet-Draft TE YANG Data Model February 2026 path computation server."; } uses te-types:te-generic-node-id; description "Address of the external path computation server."; } leaf compute-only { when "../use-path-computation = 'true'" { description "Applicable when path computation is requested."; } type empty; description "When present, the path is computed, but no resources are committed or reserved in the network. The path may be recomputed upon topology changes."; } leaf use-path-computation { when "derived-from-or-self(../path-computation-method, " + "'te-types:path-locally-computed')"; type boolean; default "true"; description "When 'true' indicates the path is dynamically computed and/or validated against the Traffic-Engineering Database (TED), and when 'false' indicates no path expansion or validation against the TED is required."; } leaf lockdown { type empty; description "When present, indicates the existing path should not be globally repaired or reoptimized."; } leaf path-scope { type identityref { base te-types:path-scope-type; } default "te-types:path-scope-end-to-end"; config false; description "Indicates whether the path is a segment or portion of the full path, or is an end-to-end path for the TE Tunnel."; } } Saad, et al. Expires 28 August 2026 [Page 29] Internet-Draft TE YANG Data Model February 2026 grouping path-compute-info { description "Attributes used for path computation request."; uses tunnel-associations-properties; uses te-types:generic-path-optimization; leaf named-path-constraint { if-feature "te-types:named-path-constraints"; type leafref { path "/te:te/te:globals/te:named-path-constraints/" + "te:named-path-constraint/te:name"; } description "Reference to a globally defined named path constraint set."; } uses path-constraints-common; } grouping path-forward-properties { description "The path preference."; leaf preference { type uint8 { range "1..255"; } default "1"; description "Specifies a preference for this path. The lower the number higher the preference."; } leaf co-routed { when "/te:te/te:tunnels/te:tunnel/te:bidirectional = 'true'" { description "Applicable to bidirectional tunnels only."; } type boolean; default "false"; description "When set to true, indicates whether the reverse path must be co-routed with the primary."; } } grouping k-requested-paths { description "The k-shortest paths requests."; leaf k-requested-paths { type uint8; default "1"; Saad, et al. Expires 28 August 2026 [Page 30] Internet-Draft TE YANG Data Model February 2026 description "The number of k-shortest paths requested from the path computation server, which are returned in order based on their computed optimization objective costs."; } } grouping path-state { description "TE per path state parameters."; uses path-computation-response; container lsp-provisioning-error-infos { config false; description "LSP provisioning error information."; list lsp-provisioning-error-info { description "List of LSP provisioning error info entries."; leaf error-reason { type identityref { base te-types:lsp-provisioning-error-reason; } description "LSP provision error type."; } leaf error-description { type string; description "The textual representation of the error that occurred during LSP provisioning."; } leaf error-timestamp { type yang:date-and-time; description "Timestamp of when the reported error occurred."; } leaf error-node-id { type te-types:te-node-id; description "Node identifier of node where error occurred."; } leaf error-link-id { type te-types:te-tp-id; description "Link ID where the error occurred."; } leaf lsp-id { type uint16; Saad, et al. Expires 28 August 2026 [Page 31] Internet-Draft TE YANG Data Model February 2026 description "The LSP-ID for which LSP provisioning error was returned."; } } } container lsps { config false; description "The TE LSPs container."; list lsp { key "node lsp-id"; description "List of LSPs associated with the tunnel."; leaf tunnel-name { type leafref { path "/te:te/te:lsps/te:lsp/te:tunnel-name"; } description "TE tunnel name."; } leaf node { type leafref { path "/te:te/te:lsps/te:lsp[tunnel-name=" + "current()/../te:tunnel-name][lsp-id=" + "current()/../te:lsp-id]/te:node"; } description "The node where the LSP state resides."; } leaf lsp-id { type leafref { path "/te:te/te:lsps/te:lsp[tunnel-name=" + "current()/../tunnel-name]/te:lsp-id"; } description "The TE LSP identifier."; } leaf state-change-timestamp { type yang:date-and-time; description "Indicates the time at which the LSP operational state was last updated."; } } } } grouping path-computation-response { description "Attributes reported by path computation response."; Saad, et al. Expires 28 August 2026 [Page 32] Internet-Draft TE YANG Data Model February 2026 container computed-paths-properties { config false; description "Computed path properties container."; list computed-path-properties { key "k-index"; description "List of computed paths."; leaf k-index { type uint8; description "The k-th path returned from the computation server. A lower k value path is more optimal than higher k value paths"; } uses te-types:generic-path-properties { augment "path-properties" { description "additional path properties returned by path computation."; uses te-types:te-bandwidth; leaf disjointness-type { type te-types:te-path-disjointness; description "The type of resource disjointness. When reported for a primary path, it represents the minimum level of disjointness of all the secondary paths. When reported for a secondary path, it represents the disjointness of the secondary path."; } leaf last-computed-timestamp { type yang:date-and-time; description "Timestamp of when the path was last computed."; } } } } } container computed-path-error-infos { config false; description "Path computation information container."; list computed-path-error-info { description "List of path computation info entries."; leaf error-description { type string; Saad, et al. Expires 28 August 2026 [Page 33] Internet-Draft TE YANG Data Model February 2026 description "Textual representation of the error that occurred during path computation."; } leaf error-timestamp { type yang:date-and-time; description "Timestamp of last path computation attempt."; } leaf error-reason { type identityref { base te-types:path-computation-error-reason; } description "Reason for the path computation error."; } } } } grouping protection-restoration-properties { description "Protection and restoration parameters."; container protection { description "Protection parameters."; leaf protection-type { type identityref { base te-types:lsp-protection-type; } default "te-types:lsp-protection-unprotected"; description "LSP protection type."; } leaf protection-reversion-disable { type boolean; default "false"; description "Disable protection reversion to working path."; } leaf hold-off-time { type uint32; units "milliseconds"; description "The time between the declaration of an SF or SD condition and the initialization of the protection switching algorithm."; reference Saad, et al. Expires 28 August 2026 [Page 34] Internet-Draft TE YANG Data Model February 2026 "RFC 4427: Recovery (Protection and Restoration) Terminology for Generalized Multi-Protocol Label Switching (GMPLS)."; } leaf wait-to-revert { type uint16; units "seconds"; description "Time to wait before attempting LSP reversion."; reference "RFC 4427: Recovery (Protection and Restoration) Terminology for Generalized Multi-Protocol Label Switching (GMPLS)."; } leaf aps-signal-id { type uint8 { range "1..255"; } default "1"; description "The Automatic Protection Switching (APS) signal number used to reference the traffic of this tunnel. The default value for normal traffic is 1. The default value for extra-traffic is 255. If not specified, non-default values can be assigned by the server, if and only if, the server controls both endpoints."; reference "ITU_G.808.1: Generic protection switching - Linear trail and subnetwork protection."; } } container restoration { description "Restoration parameters."; leaf restoration-type { type identityref { base te-types:lsp-restoration-type; } description "LSP restoration type."; } leaf restoration-scheme { type identityref { base te-types:restoration-scheme-type; } description "LSP restoration scheme."; Saad, et al. Expires 28 August 2026 [Page 35] Internet-Draft TE YANG Data Model February 2026 } leaf restoration-reversion-disable { type boolean; default "false"; description "When 'true', disables restoration reversion to the working path."; } leaf hold-off-time { type uint32; units "milliseconds"; description "The time between the declaration of an SF or SD condition and the initialization of the protection switching algorithm."; reference "RFC 4427: Recovery (Protection and Restoration) Terminology for Generalized Multi-Protocol Label Switching (GMPLS)."; } leaf wait-to-restore { type uint16; units "seconds"; description "Time to wait before attempting LSP restoration."; reference "RFC 4427: Recovery (Protection and Restoration) Terminology for Generalized Multi-Protocol Label Switching (GMPLS)."; } leaf wait-to-revert { type uint16; units "seconds"; description "Time to wait before attempting LSP reversion."; reference "RFC 4427: Recovery (Protection and Restoration) Terminology for Generalized Multi-Protocol Label Switching (GMPLS)."; } } } grouping tunnel-associations-properties { description "TE tunnel association grouping."; container association-objects { description Saad, et al. Expires 28 August 2026 [Page 36] Internet-Draft TE YANG Data Model February 2026 "TE tunnel associations."; list association-object { key "association-key"; unique "type id source/id source/type"; description "List of association base objects."; reference "RFC 4872: RSVP-TE Extensions in Support of End-to-End Generalized Multi-Protocol Label Switching (GMPLS) Recovery."; leaf association-key { type string; description "Association key used to identify a specific association in the list"; } leaf type { type identityref { base te-types:association-type; } description "Association type."; reference "RFC 4872: RSVP-TE Extensions in Support of End-to-End Generalized Multi-Protocol Label Switching (GMPLS) Recovery."; } leaf id { type uint16; description "Association identifier."; reference "RFC 4872: RSVP-TE Extensions in Support of End-to-End Generalized Multi-Protocol Label Switching (GMPLS) Recovery."; } container source { uses te-types:te-generic-node-id; description "Association source."; reference "RFC 4872: RSVP-TE Extensions in Support of End-to-End Generalized Multi-Protocol Label Switching (GMPLS) Recovery."; } } list association-object-extended { key "association-key"; Saad, et al. Expires 28 August 2026 [Page 37] Internet-Draft TE YANG Data Model February 2026 unique "type id source/id source/type global-source extended-id"; description "List of extended association objects."; reference "RFC 6780: RSVP ASSOCIATION Object Extensions"; leaf association-key { type string; description "Association key used to identify a specific association in the list"; } leaf type { type identityref { base te-types:association-type; } description "Association type."; reference "RFC 4427: Recovery (Protection and Restoration) Terminology for Generalized Multi-Protocol Label Switching (GMPLS) RFC 6780: RSVP ASSOCIATION Object Extensions"; } leaf id { type uint16; description "Association identifier."; reference "RFC 4427: Recovery (Protection and Restoration) Terminology for Generalized Multi-Protocol Label Switching (GMPLS) RFC 6780: RSVP ASSOCIATION Object Extensions"; } container source { uses te-types:te-generic-node-id; description "Association source."; reference "RFC 4427: Recovery (Protection and Restoration) Terminology for Generalized Multi-Protocol Label Switching (GMPLS) RFC 6780: RSVP ASSOCIATION Object Extensions"; } leaf global-source { type uint32; description "Association global source."; Saad, et al. Expires 28 August 2026 [Page 38] Internet-Draft TE YANG Data Model February 2026 reference "RFC 6780: RSVP ASSOCIATION Object Extensions"; } leaf extended-id { type yang:hex-string; description "Association extended identifier."; reference "RFC 6780: RSVP ASSOCIATION Object Extensions"; } } } } grouping tunnel-end-point { description "Common grouping used to specify the tunnel source and destination end-points."; leaf node-id { type nw:node-id; description "The TE tunnel end-point node identifier"; } leaf te-node-id { type te-types:te-node-id; description "The TE tunnel end-point TE node identifier"; } leaf tunnel-tp-id { when "../node-id or ../te-node-id" { description "The TE tunnel termination point identifier is local to a node"; } type binary; description "The TE tunnel end-point TE tunnel termination point identifier"; } } /* Some of the groupings defined in this module are re-used * in path-computation YANG model * defined in [I-D.ietf-teas-yang-path-computation] */ grouping tunnel-common-attributes { description "Common grouping to define the TE tunnel parameters"; container source { Saad, et al. Expires 28 August 2026 [Page 39] Internet-Draft TE YANG Data Model February 2026 description "TE tunnel source end-point."; uses tunnel-end-point; } container destination { description "TE tunnel destination end-point."; uses tunnel-end-point; } leaf bidirectional { type boolean; default "false"; description "When 'true', it indicates a bidirectional tunnel"; } } /* This grouping is re-used in path-computation YANG * model defined in [I-D.ietf-teas-yang-path-computation] */ grouping tunnel-hierarchy-properties { description "A grouping for TE tunnel hierarchy information."; container hierarchy { description "Container for TE hierarchy related information."; container dependency-tunnels { description "List of tunnels that this tunnel can be potentially dependent on."; list dependency-tunnel { key "name"; description "A tunnel entry that this tunnel can potentially depend on."; leaf name { type tunnel-ref; description "Dependency tunnel name. The tunnel may not have been instantiated yet."; } uses te-types:encoding-and-switching-type; } } container hierarchical-link { description "Identifies a hierarchical link (in client layer) that this tunnel is associated with. By default, the topology of the hierarchical link is the same topology of Saad, et al. Expires 28 August 2026 [Page 40] Internet-Draft TE YANG Data Model February 2026 the tunnel;"; reference "RFC 4206: Label Switched Paths (LSP) Hierarchy with Generalized Multi-Protocol Label Switching (GMPLS) Traffic Engineering (TE)"; leaf enable { type boolean; default "false"; description "When 'true', enables the hierarchical link properties supported by this tunnel"; } leaf local-node-id { type nw:node-id; description "The local node identifier."; } leaf local-te-node-id { type te-types:te-node-id; description "The local TE node identifier."; } leaf local-link-tp-id { type nt:tp-id; description "The local link termination point identifier."; reference "RFC 8345: A YANG Data Model for Network Topologies"; } leaf local-te-link-tp-id { type te-types:te-tp-id; description "The local TE link termination point identifier."; } leaf remote-node-id { type nw:node-id; description "The remote node identifier."; } leaf remote-link-tp-id { type nt:tp-id; description "The remote link termination point identifier."; reference "RFC 8345: A YANG Data Model for Network Topologies"; } leaf remote-te-link-tp-id { type te-types:te-tp-id; Saad, et al. Expires 28 August 2026 [Page 41] Internet-Draft TE YANG Data Model February 2026 description "The remote TE link termination point identifier."; } leaf remote-te-node-id { type te-types:te-node-id; description "Remote TE node identifier."; } leaf link-id { type nt:link-id; description "A network topology assigned identifier to the link"; reference "RFC 8345: A YANG Data Model for Network Topologies"; } leaf network-id { type nw:network-id; description "The network topology identifier where the hierarchical link supported by this TE tunnel is instantiated."; } uses te-types:te-topology-identifier { description "The TE topology identifier where the hierarchical link supported by this TE tunnel is instantiated."; } } } } grouping path-constraints-common { description "Global named path constraints configuration grouping."; uses te-types:common-path-constraints-attributes; uses te-types:generic-path-disjointness; uses te-types:path-constraints-route-objects; container path-in-segment { presence "The end-to-end tunnel starts in a previous domain; this tunnel is a segment in the current domain."; description "If an end-to-end tunnel crosses multiple domains using the same technology, some additional constraints have to be taken in consideration in each domain. This TE tunnel segment is stitched to the upstream TE tunnel segment."; uses te-types:label-set-info; } Saad, et al. Expires 28 August 2026 [Page 42] Internet-Draft TE YANG Data Model February 2026 container path-out-segment { presence "The end-to-end tunnel is not terminated in this domain; this tunnel is a segment in the current domain."; description "If an end-to-end tunnel crosses multiple domains using the same technology, some additional constraints have to be taken in consideration in each domain. This TE tunnel segment is stitched to the downstream TE tunnel segment."; uses te-types:label-set-info; } } /** * TE container */ container te { description "TE global container."; leaf enable { type boolean; description "When 'true', the TE component features are enabled."; } /* TE Global Data */ container globals { description "Globals TE system-wide configuration data container."; container named-admin-groups { description "TE named admin groups container."; list named-admin-group { if-feature "te-types:extended-admin-groups"; if-feature "te-types:named-extended-admin-groups"; key "name"; description "List of named TE admin-groups."; leaf name { type string; description "A name that uniquely identifies a TE interface named admin-group."; } leaf bit-position { type uint32; Saad, et al. Expires 28 August 2026 [Page 43] Internet-Draft TE YANG Data Model February 2026 description "Bit-position value for a named Administrative Group (AG). The value is an integer that represents one of the bit positions in the administrative group bitmask. Values for bit-positions between 0 and 31 are inter- preted as the original 32 bit AGs. Values of bit- positions >=32 are interpreted as Extended Administrative Group (EAG) values as per RFC 7308."; reference "RFC 3209: RSVP-TE: Extensions to RSVP for LSP Tunnels RFC 7308: Extended Administrative Groups in MPLS Traffic Engineering (MPLS-TE)"; } } } container named-srlgs { description "TE named SRLGs container."; list named-srlg { if-feature "te-types:named-srlg-groups"; key "name"; description "A list of named SRLG groups."; leaf name { type string; description "A name that uniquely identifies a TE interface named SRLG."; } leaf value { type te-types:srlg; description "An SRLG value."; } leaf cost { type uint32; description "The cost associated with an SRLG. This is used as a penalty during path computation when the TE path traverses a link with this SRLG."; } } } container named-path-constraints { description "TE named path constraints container."; Saad, et al. Expires 28 August 2026 [Page 44] Internet-Draft TE YANG Data Model February 2026 list named-path-constraint { if-feature "te-types:named-path-constraints"; key "name"; leaf name { type string; description "A name that uniquely identifies a path constraint set."; } uses path-constraints-common; description "A list of named path constraints."; } } } /* TE Tunnel Data */ container tunnels { description "Tunnels TE configuration data container."; list tunnel { key "name"; description "The list of TE tunnels."; leaf name { type string; description "TE tunnel name."; } leaf alias { type string; description "An alternate name of the TE tunnel that can be modified anytime during its lifetime."; } leaf identifier { type uint32; description "A numeric identifier for the tunnel, unique within the scope of the ingress node. While the 'name' leaf serves as a human-readable management key, this 'identifier' corresponds to the Tunnel ID used in control plane signaling (e.g., the RSVP-TE SESSION object as defined in RFC 3209), allowing for correlation between management state and network-wide signaling."; reference "RFC 3209: RSVP-TE: Extensions to RSVP for LSP Tunnels"; Saad, et al. Expires 28 August 2026 [Page 45] Internet-Draft TE YANG Data Model February 2026 } leaf color { type uint32; description "A TE Tunnel [RFC3209] can be associated with an intent or objective (e.g., low latency) by tagging it with a color. This color attribute is used as a guiding criterion for mapping services onto the TE Tunnel [RFC9012][RFC9256]."; reference "RFC 9012: The BGP Tunnel Encapsulation Attribute"; } leaf description { type string; default "None"; description "Textual description for this TE tunnel."; } leaf admin-state { type identityref { base te-types:tunnel-admin-state-type; } default "te-types:tunnel-admin-state-up"; description "TE tunnel administrative state."; } leaf operational-state { type identityref { base te-types:tunnel-state-type; } config false; description "TE tunnel operational state."; } leaf state-change-timestamp { type yang:date-and-time; description "Indicates the time at which the TE tunnel's operational state was last updated."; } uses te-types:encoding-and-switching-type; uses tunnel-common-attributes; container controller { description "Contains tunnel data relevant to external controllers. This target node may be augmented by external modules, for example, to add data for PCEP initiated and/or delegated tunnels."; Saad, et al. Expires 28 August 2026 [Page 46] Internet-Draft TE YANG Data Model February 2026 leaf protocol-origin { type identityref { base te-types:protocol-origin-type; } description "The protocol origin for instantiating the tunnel."; } leaf controller-entity-id { type string; description "An identifier that is associated with the entity that controls the tunnel as defined in RFC 8232."; reference "RFC 8232: Optimizations of Label Switched Path State Synchronization Procedures for a Stateful PCE"; } } leaf reoptimize-timer { type uint16; units "seconds"; description "Frequency of reoptimization of a traffic-engineered LSP. A value of 0 means that the LSP is never reoptimized"; } uses tunnel-associations-properties; uses protection-restoration-properties; uses te-types:tunnel-constraints; uses tunnel-hierarchy-properties; container primary-paths { description "The set of primary paths."; reference "RFC 4872: RSVP-TE Extensions in Support of End-to-End Generalized Multi-Protocol Label Switching (GMPLS) Recovery."; list primary-path { key "name"; description "List of primary paths for this tunnel."; leaf active { type boolean; config false; description "When 'true', indicates an active path has been selected from the primary paths list."; } Saad, et al. Expires 28 August 2026 [Page 47] Internet-Draft TE YANG Data Model February 2026 uses path-common-properties; uses path-forward-properties; uses k-requested-paths; uses path-compute-info; uses path-state; container primary-reverse-path { when "../../../te:bidirectional = 'true'"; description "The reverse primary path properties."; uses path-common-properties; uses path-compute-info; uses path-state; container candidate-secondary-reverse-paths { description "The set of referenced candidate reverse secondary paths from the full set of secondary reverse paths which may be used for this primary path."; list candidate-secondary-reverse-path { key "secondary-reverse-path"; ordered-by user; description "List of candidate secondary reverse paths"; leaf secondary-reverse-path { type leafref { path "../../../../../../" + "te:secondary-reverse-paths/" + "te:secondary-reverse-path/te:name"; } description "A reference to the secondary reverse path that may be utilized when the containing primary reverse path is in use."; } leaf active { type boolean; config false; description "When 'true', indicates an active path has been selected from the secondary reverse paths list."; } } } } container candidate-secondary-paths { description "The set of candidate secondary paths which may be used for this primary path. When secondary paths are Saad, et al. Expires 28 August 2026 [Page 48] Internet-Draft TE YANG Data Model February 2026 specified in the list the path of the secondary LSP in use must be restricted to those paths referenced. The priority of the secondary paths is specified within the list. Higher priority values are less preferred - that is to say that a path with priority 0 is the most preferred path. In the case that the list is empty, any secondary path may be utilized when the current primary path is in use."; list candidate-secondary-path { key "secondary-path"; ordered-by user; description "List of candidate secondary paths for this tunnel."; leaf secondary-path { type leafref { path "../../../../../te:secondary-paths/" + "te:secondary-path/te:name"; } description "A reference to the secondary path that may be utilized when the containing primary path is in use."; } leaf active { type boolean; config false; description "When 'true', indicates an active path has been selected from the candidate secondary paths."; } } } } } container secondary-paths { description "The set of secondary paths."; reference "RFC 4872: RSVP-TE Extensions in Support of End-to-End Generalized Multi-Protocol Label Switching (GMPLS) Recovery."; list secondary-path { key "name"; description "List of secondary paths for this tunnel."; uses path-common-properties; Saad, et al. Expires 28 August 2026 [Page 49] Internet-Draft TE YANG Data Model February 2026 leaf preference { type uint8 { range "1..255"; } default "1"; description "Specifies a preference for this path. The lower the number, the higher the preference."; } leaf secondary-reverse-path { type leafref { path "../../../" + "te:secondary-reverse-paths/" + "te:secondary-reverse-path/te:name"; } description "A reference to the reverse secondary path when co-routed with the secondary path."; } uses path-compute-info; uses protection-restoration-properties; uses path-state; } } container secondary-reverse-paths { description "The set of secondary reverse paths."; list secondary-reverse-path { key "name"; description "List of secondary paths for this tunnel."; uses path-common-properties; leaf preference { type uint8 { range "1..255"; } default "1"; description "Specifies a preference for this path. The lower the number higher the preference. Paths that have the same preference will be activated together."; } uses path-compute-info; uses protection-restoration-properties; uses path-state; } } action tunnel-action { Saad, et al. Expires 28 August 2026 [Page 50] Internet-Draft TE YANG Data Model February 2026 description "Action commands to manipulate the TE tunnel state."; reference "RFC 3209: RSVP-TE: Extensions to RSVP for LSP Tunnels, Section 2.5"; input { leaf action-type { type identityref { base te-types:tunnel-action-type; } description "The action to be invoked on the TE tunnel."; } } output { leaf action-result { type identityref { base te-types:te-action-result; } description "The result of the tunnel action operation."; } } } action protection-external-commands { description "Actions to manipulate the protection external commands of the TE tunnel."; reference "RFC 4427: Recovery (Protection and Restoration) Terminology for Generalized Multi-Protocol Label Switching (GMPLS)"; input { leaf protection-external-command { type identityref { base te-types:protection-external-commands; } description "Protection external command."; } leaf ingress-node { type boolean; default "true"; description "When 'true', indicates that the action is applied on the ingress node. By default, the action applies to the ingress node"; Saad, et al. Expires 28 August 2026 [Page 51] Internet-Draft TE YANG Data Model February 2026 } leaf egress-node { type boolean; default "false"; description "When 'true', indicates that the action is applied on the egress node. By default, the action applies to the ingress node."; } leaf path-name { type string; description "The name of the path that the external command applies to."; } leaf path-type { type te-types:path-type; description "The type of the path that the external command applies to."; } leaf traffic-type { type enumeration { enum normal-traffic { description "The manual-switch or forced-switch command applies to the normal traffic (this Tunnel)."; } enum null-traffic { description "The manual-switch or forced-switch command applies to the null traffic."; } enum extra-traffic { description "The manual-switch or forced-switch command applies to the extra traffic (the extra-traffic Tunnel sharing protection bandwidth with this Tunnel)."; } } description "Indicates whether the manual-switch or forced-switch commands applies to the normal traffic, the null traffic or the extra-traffic."; reference "RFC 4427: Recovery (Protection and Restoration) Terminology for Generalized Multi-Protocol Saad, et al. Expires 28 August 2026 [Page 52] Internet-Draft TE YANG Data Model February 2026 Label Switching (GMPLS)."; } leaf extra-traffic-tunnel-ref { type tunnel-ref; description "In case there are multiple extra-traffic tunnels sharing protection bandwidth with this Tunnel (m:n protection), represents which extra-traffic Tunnel the manual-switch or forced-switch to extra-traffic command applies to."; } } } } } /* TE LSPs Data */ container lsps { config false; description "TE LSPs state container."; list lsp { key "tunnel-name lsp-id node"; unique "source destination tunnel-id lsp-id " + "extended-tunnel-id"; description "List of LSPs associated with the tunnel."; leaf tunnel-name { type string; description "The TE tunnel name."; } leaf lsp-id { type uint16; description "An identifier unique in the context of the LSP head-end. For example, as used in the RSVP-TE SENDER_TEMPLATE and FILTER_SPEC objects. The value can be changed to allow a sender to share resources with itself."; reference "RFC 3209"; } leaf node { type te-types:te-node-id; description "The node where the LSP state is retrieved."; } leaf source { type te-types:te-node-id; Saad, et al. Expires 28 August 2026 [Page 53] Internet-Draft TE YANG Data Model February 2026 description "The address of the ingress LSP endpoint that identifies the start of the tunnel. This typically corresponds to the Tunnel Sender Address extracted from the RSVP-TE SENDER_TEMPLATE object."; reference "RFC 3209: RSVP-TE: Extensions to RSVP for LSP Tunnels"; } leaf destination { type te-types:te-node-id; description "The address of the egress LSP endpoint that identifies the end of the tunnel. This typically corresponds to the Tunnel Endpoint Address extracted from the RSVP-TE SESSION object."; reference "RFC 3209: RSVP-TE: Extensions to RSVP for LSP Tunnels"; } leaf tunnel-id { type uint16; description "An identifier of the tunnel that remains constant over the life of the tunnel. For example, this may be the Tunnel ID extracted from RSVP-TE SESSION object."; reference "RFC 3209"; } leaf extended-tunnel-id { type yang:dotted-quad; description "A qualifier used to ensure the global uniqueness of the tunnel identifier. It carries a 4-byte or 16-byte value, typically corresponding to the Extended Tunnel ID extracted from the RSVP-TE SESSION object as defined in RFC 3209."; reference "RFC 3209"; } leaf operational-state { type identityref { base te-types:lsp-state-type; } description "The LSP operational state."; } leaf signaling-type { type identityref { base te-types:path-signaling-type; Saad, et al. Expires 28 August 2026 [Page 54] Internet-Draft TE YANG Data Model February 2026 } description "The signaling protocol used to set up this LSP."; } leaf origin-type { type enumeration { enum ingress { description "Origin ingress."; } enum egress { description "Origin egress."; } enum transit { description "Origin transit."; } } description "The origin of the LSP relative to the location of the local switch in the path."; } leaf lsp-resource-status { type enumeration { enum primary { description "A primary LSP is a fully established LSP for which the resource allocation has been committed at the data plane."; } enum secondary { description "A secondary LSP is an LSP that has been provisioned in the control plane only; e.g. resource allocation has not been committed at the data plane."; } } description "LSP resource allocation state."; reference "RFC 4872, section 4.2.1"; } leaf lockout-of-normal { type boolean; description "When set to 'true', it represents a lockout of normal traffic external command. When set to 'false', it Saad, et al. Expires 28 August 2026 [Page 55] Internet-Draft TE YANG Data Model February 2026 represents a clear lockout of normal traffic external command. The lockout of normal traffic command applies to this Tunnel."; reference "RFC 4427"; } leaf freeze { type boolean; description "When set to 'true', it represents a freeze external command. When set to 'false', it represents a clear freeze external command. The freeze command applies to all the Tunnels which are sharing the protection resources with this Tunnel."; reference "RFC 4427"; } leaf lsp-protection-role { type enumeration { enum working { description "A working LSP must be a primary LSP whilst a protecting LSP can be either a primary or a secondary LSP. Also, known as protected LSPs when working LSPs are associated with protecting LSPs."; } enum protecting { description "A secondary LSP is an LSP that has been provisioned in the control plane only; e.g. resource allocation has not been committed at the data plane."; } } description "LSP role type."; reference "RFC 4872, section 4.2.1"; } leaf lsp-protection-state { type identityref { base te-types:lsp-protection-state; } config false; description "The reported protection state controlling which tunnel is using the resources of the protecting LSP."; } leaf ingress-node-id { Saad, et al. Expires 28 August 2026 [Page 56] Internet-Draft TE YANG Data Model February 2026 type te-types:te-node-id; description "Indicates the te-node-id of the ingress node of the TE tunnel or tunnel segment when the protection action is applied to the ingress node or the Wait To Restore (WTR) timer is active. This is set to '0.0.0.0' when the controller is not aware of the te-node-id of ingress-node."; } leaf egress-node-id { type te-types:te-node-id; description "Indicates the te-node-id of the egress node of the TE tunnel or tunnel segment when the protection action is applied to the ingress node or the WTR timer is active. This is set to '0.0.0.0' when the controller is not aware of the te-node-id of ingress-node."; } container lsp-actual-route-information { description "RSVP recorded route object information."; list lsp-actual-route-information { when "../../origin-type = 'ingress'" { description "Applicable on ingress LSPs only."; } key "index"; description "Record route list entry."; uses te-types:record-route-state; } } } } } /* TE Tunnel RPCs/execution Data */ rpc tunnels-path-compute { description "This RPC is a generic API whose input and output parameters are expected to be provided by augments to this module."; reference "RFC 4655: A Path Computation Element (PCE)-Based Architecture."; input { container path-compute-info { Saad, et al. Expires 28 August 2026 [Page 57] Internet-Draft TE YANG Data Model February 2026 /* * An external path compute module may augment this * target. */ description "RPC input information."; } } output { container path-compute-result { /* * An external path compute module may augment this * target. */ description "RPC output information."; } } } rpc tunnels-actions { description "RPC that manipulates the state of a TE tunnel."; reference "RFC 3209: RSVP-TE: Extensions to RSVP for LSP Tunnels, Section 2.5"; input { container tunnel-info { description "TE tunnel information."; choice filter-type { mandatory true; description "Filter choice."; case all-tunnels { leaf all { type empty; mandatory true; description "When present, applies the action on all TE tunnels."; } } case one-tunnel { leaf tunnel { type tunnel-ref; description "Apply action on the specific TE tunnel."; Saad, et al. Expires 28 August 2026 [Page 58] Internet-Draft TE YANG Data Model February 2026 } } } } container action-info { description "TE tunnel action information."; leaf action { type identityref { base te-types:tunnel-action-type; } description "The action type."; } leaf disruptive { when "derived-from-or-self(../action, " + "'te-types:tunnel-action-reoptimize')"; type empty; description "Specifies whether reoptimization operations, particularly when multiple tunnels are involved, are permitted to cause traffic disruption on some TE tunnels."; } } } output { leaf action-result { type identityref { base te-types:te-action-result; } description "The result of the tunnel action operation."; } } } } 6. TE Device YANG Model The device TE YANG module 'ietf-te-device' models data that is specific to managing a TE device. This module augments the generic TE YANG module. Saad, et al. Expires 28 August 2026 [Page 59] Internet-Draft TE YANG Data Model February 2026 6.1. Module Structure The 'ietf-te-device' module defines the configuration and operational state data that is specific to the device, including those related to the TE subsystem, tunnels, LSPs, and interfaces. 6.1.1. TE Device Globals, Tunnels and LSPs The 'ietf-te-device' module augments the generic 'ietf-te' module at the 'globals', 'tunnels', and 'lsps' levels to include the device- specific configurations and operational state. Figure 7 shows the 'ietf-te-device' subtree generated with depth=4 that describes those augmentations. module: ietf-te-device augment /te:te/te:globals: +--rw lsp-install-interval? uint32 +--rw lsp-cleanup-interval? uint32 +--rw lsp-invalidation-interval? uint32 augment /te:te/te:tunnels/te:tunnel: +--rw path-invalidation-action? identityref +--rw lsp-install-interval? uint32 +--rw lsp-cleanup-interval? uint32 +--rw lsp-invalidation-interval? uint32 augment /te:te/te:lsps/te:lsp: +--ro lsp-timers | +--ro uptime? uint32 | +--ro time-to-install? uint32 | +--ro time-to-destroy? uint32 +--ro downstream-info | .. +--ro upstream-info .. Figure 7: TE Device Augmentations to Globals, Tunnels, and LSPs YANG Subtree The following is the description of the augmented data at each level. Global Timers (Augmenting /te:te/te:globals): These are device-specific global configuration parameters related to LSP timers, applied system-wide. lsp-install-interval Saad, et al. Expires 28 August 2026 [Page 60] Internet-Draft TE YANG Data Model February 2026 : An optional leaf that specifies the delay time, in seconds, before a newly provisioned LSP is installed into the forwarding plane to carry traffic. lsp-cleanup-interval : An optional leaf that specifies the delay time, in seconds, before an LSP is completely removed from the system after it is no longer in use. lsp-invalidation-interval : An optional leaf that specifies the delay time, in seconds, during which a TE LSP's path is considered invalid before any corrective action is taken. Tunnel Device-Dependent Attributes (Augmenting /te:te/te:tunnels/ te:tunnel). These are device-specific configuration parameters that apply to individual TE Tunnels: path-invalidation-action : An optional identityref that specifies the action to be taken when a TE Tunnel's path is deemed invalid (e.g., tear down, recompute). lsp-install-interval : An optional leaf that specifies the delay time, in seconds, for this specific TE Tunnel before its LSPs are installed into the forwarding plane. This value can override the global lsp-install- interval. lsp-cleanup-interval : An optional leaf that specifies the delay time, in seconds, for this specific TE Tunnel before its LSPs are cleaned up. This value can override the global lsp-cleanup-interval. lsp-invalidation-interval : An optional leaf that specifies the delay time, in seconds, for this specific TE Tunnel during which its path is considered invalid before action is taken. This value can override the global lsp-invalidation-interval. LSP Device-Dependent State (Augmenting /te:te/te:lsps/te:lsp). Saad, et al. Expires 28 August 2026 [Page 61] Internet-Draft TE YANG Data Model February 2026 These are read-only operational state parameters providing device- specific details for individual LSPs: lsp-timers : A container that holds various timer-related operational state for an LSP, applicable primarily to ingress LSPs. uptime : An optional leaf that indicates the total time, in seconds, that the LSP has been operational. time-to-install : An optional leaf that indicates the remaining time, in seconds, for a new LSP to be fully instantiated and ready to carry traffic. time-to-destroy : An optional leaf that indicates the remaining time, in seconds, before an existing LSP is torn down. downstream-info : A container that holds information about the downstream neighbor and label for the LSP, applicable when the LSP is not at its egress. upstream-info : A container that holds information about the upstream neighbor and label for the LSP, applicable when the LSP is not at its ingress. 6.1.2. TE Device Interfaces Figure 8 shows the TE interface subtree from the TE device module 'ietf-te-device' with depth=4. The full tree diagram is shown in Appendix B. Saad, et al. Expires 28 August 2026 [Page 62] Internet-Draft TE YANG Data Model February 2026 module: ietf-te-device augment /te:te: +--rw interfaces +--rw threshold-type? enumeration +--rw delta-percentage? rt-types:percentage +--rw threshold-specification? enumeration +--rw up-thresholds* rt-types:percentage +--rw down-thresholds* rt-types:percentage +--rw up-down-thresholds* rt-types:percentage +--rw interface* [name] +--rw name if:interface-ref +--rw te-metric? | te-types:te-metric +--rw (admin-group-type)? | +--:(value-admin-groups) | | ... | +--:(named-admin-groups) | ... +--rw (srlg-type)? | +--:(value-srlgs) | | ... | +--:(named-srlgs) | ... +--rw threshold-type? enumeration +--rw delta-percentage? | rt-types:percentage +--rw threshold-specification? enumeration +--rw up-thresholds* | rt-types:percentage +--rw down-thresholds* | rt-types:percentage +--rw up-down-thresholds* | rt-types:percentage +--rw switching-capabilities* [switching-capability] | +--rw switching-capability identityref | +--rw encoding? identityref +--ro te-advertisements-state +--ro flood-interval? uint32 +--ro last-flooded-time? uint32 +--ro next-flooded-time? uint32 +--ro last-flooded-trigger? enumeration +--ro advertised-level-areas* [level-area] ... Figure 8: TE interfaces YANG subtree from the TE device YANG data model Saad, et al. Expires 28 August 2026 [Page 63] Internet-Draft TE YANG Data Model February 2026 The main elements under the interfaces container are: threshold-type: An optional enumeration that specifies the type of thresholding mechanism used for flooding bandwidth updates for all TE interfaces on the device. Options include 'delta' (flooding on a change greater than a specified delta) or 'threshold-crossed' (flooding when bandwidth crosses a defined threshold). delta-percentage: An optional percentage value, used when threshold-type is 'delta', indicating the change in reservable bandwidth that triggers an IGP update for all TE interfaces. threshold-specification: An optional enumeration, used when threshold-type is 'threshold- crossed', to define whether a single set of 'mirrored-up-down' thresholds or separate 'separate-up-down' thresholds are used for increasing and decreasing bandwidth. This applies globally to all TE interfaces. up-thresholds: A list of percentage values, used with 'separate-up-down' thresholding, that define the points at which bandwidth updates are triggered when the reservable bandwidth is increasing across all TE interfaces. down-thresholds: A list of percentage values, used with 'separate-up-down' thresholding, that define the points at which bandwidth updates are triggered when the reservable bandwidth is decreasing across all TE interfaces. up-down-thresholds: A list of percentage values, used with 'mirrored-up-down' thresholding, that define the points at which bandwidth updates are triggered for both increasing and decreasing reservable bandwidth across all TE interfaces. interface: Saad, et al. Expires 28 August 2026 [Page 64] Internet-Draft TE YANG Data Model February 2026 A list of individual TE interfaces configured on the device. Each entry represents a network interface enabled for Traffic Engineering and contains its specific attributes and state. A TE interface is identified by the 'name' leaf, which references an existing network interface on the device. name: A leaf that uniquely identifies the TE interface, referencing an existing network interface. te-metric: An optional leaf that holds the TE metric value associated with this specific interface, used during path computation. admin-group-type: A choice node that allows configuring administrative groups for the interface using either direct values or named references. value-admin-groups: A choice for defining administrative groups using direct bitmask values. named-admin-groups: A list of named administrative groups applied to this TE interface, referencing globally defined named administrative groups. srlg-type: A choice node that allows configuring SRLGs for the interface using either direct values or named references. value-srlgs: A list of direct SRLG values that this link is a part of. named-srlgs: A list of named SRLGs applied to this interface, referencing globally defined named SRLGs. threshold-type: Saad, et al. Expires 28 August 2026 [Page 65] Internet-Draft TE YANG Data Model February 2026 An optional enumeration, similar to the global threshold-type, but specifically for this individual TE interface, allowing per-interface override of the global bandwidth flooding behavior. delta-percentage: An optional percentage value, specific to this interface, used when its threshold-type is 'delta'. threshold-specification: An optional enumeration, specific to this interface, used when its threshold-type is 'threshold-crossed'. up-thresholds: A list of percentage values, specific to this interface, used with 'separate-up-down' thresholding for increasing bandwidth. down-thresholds: A list of percentage values, specific to this interface, used with 'separate-up-down' thresholding for decreasing bandwidth. up-down-thresholds: A list of percentage values, specific to this interface, used with 'mirrored-up-down' thresholding for both increasing and decreasing bandwidth. switching-capabilities: A list of switching capabilities supported by this interface. switching-capability: An identityref indicating a specific switching capability (e.g., Packet, Lambda, Fiber). encoding: An optional identityref indicating the LSP encoding type supported by this capability on the interface. te-advertisements-state: Saad, et al. Expires 28 August 2026 [Page 66] Internet-Draft TE YANG Data Model February 2026 A read-only container that provides operational state information related to how this TE interface's attributes are advertised. flood-interval: An optional leaf indicating the configured periodic flooding interval for this interface. last-flooded-time: An optional leaf showing the time elapsed since the last advertisement flood for this interface. next-flooded-time: An optional leaf showing the time remaining until the next scheduled advertisement flood for this interface. last-flooded-trigger: An optional enumeration indicating the event that triggered the last advertisement flood (e.g., link-up, bandwidth- change, periodic-timer). advertised-level-areas: A list of IGP level-areas in which this TE interface's link state information is advertised. 6.2. Tree Diagram Figure 9 shows the tree diagram of the device TE YANG data model defined in the 'ietf-te-device' module. module: ietf-te-device augment /te:te: +--rw interfaces +--rw threshold-type? enumeration +--rw delta-percentage? rt-types:percentage +--rw threshold-specification? enumeration +--rw up-thresholds* rt-types:percentage +--rw down-thresholds* rt-types:percentage +--rw up-down-thresholds* rt-types:percentage +--rw interface* [name] +--rw name if:interface-ref +--rw te-metric? Saad, et al. Expires 28 August 2026 [Page 67] Internet-Draft TE YANG Data Model February 2026 | te-types:te-metric +--rw (admin-group-type)? | +--:(value-admin-groups) | | +--rw (value-admin-group-type)? | | +--:(admin-groups) | | | +--rw admin-group? | | | te-types:admin-group | | +--:(extended-admin-groups) | | {te-types:extended-admin-groups}? | | +--rw extended-admin-group? | | te-types:extended-admin-group | +--:(named-admin-groups) | +--rw named-admin-groups* [named-admin-group] | {te-types:extended-admin-groups, | te-types:named-extended-admin-groups}? | +--rw named-admin-group leafref +--rw (srlg-type)? | +--:(value-srlgs) | | +--rw values* [value] | | +--rw value uint32 | +--:(named-srlgs) | +--rw named-srlgs* [named-srlg] | {te-types:named-srlg-groups}? | +--rw named-srlg leafref +--rw threshold-type? enumeration +--rw delta-percentage? | rt-types:percentage +--rw threshold-specification? enumeration +--rw up-thresholds* | rt-types:percentage +--rw down-thresholds* | rt-types:percentage +--rw up-down-thresholds* | rt-types:percentage +--rw switching-capabilities* [switching-capability] | +--rw switching-capability identityref | +--rw encoding? identityref +--ro te-advertisements-state +--ro flood-interval? uint32 +--ro last-flooded-time? uint32 +--ro next-flooded-time? uint32 +--ro last-flooded-trigger? enumeration +--ro advertised-level-areas* [level-area] +--ro level-area uint32 augment /te:te/te:globals: +--rw lsp-install-interval? uint32 +--rw lsp-cleanup-interval? uint32 +--rw lsp-invalidation-interval? uint32 Saad, et al. Expires 28 August 2026 [Page 68] Internet-Draft TE YANG Data Model February 2026 augment /te:te/te:tunnels/te:tunnel: +--rw path-invalidation-action? identityref +--rw lsp-install-interval? uint32 +--rw lsp-cleanup-interval? uint32 +--rw lsp-invalidation-interval? uint32 augment /te:te/te:lsps/te:lsp: +--ro lsp-timers | +--ro uptime? uint32 | +--ro time-to-install? uint32 | +--ro time-to-destroy? uint32 +--ro downstream-info | +--ro nhop? te-types:te-tp-id | +--ro outgoing-interface? if:interface-ref | +--ro neighbor | | +--ro id? te-gen-node-id | | +--ro type? enumeration | +--ro label? rt-types:generalized-label +--ro upstream-info +--ro phop? te-types:te-tp-id +--ro neighbor | +--ro id? te-gen-node-id | +--ro type? enumeration +--ro label? rt-types:generalized-label rpcs: +---x link-state-update +---w input +---w (filter-type) +--:(match-all) | +---w all empty +--:(match-one-interface) +---w interface? if:interface-ref Figure 9: TE Tunnel device model YANG tree diagram 6.3. YANG Module The 'ietf-te-device' module imports the following modules: * ietf-interfaces defined in [RFC8343] * ietf-routing-types defined in [RFC8294] * ietf-te-types defined in [I-D.draft-ietf-teas-rfc8776-update] * ietf-te defined in this document Saad, et al. Expires 28 August 2026 [Page 69] Internet-Draft TE YANG Data Model February 2026 file "ietf-te-device@2026-02-24.yang" module ietf-te-device { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-te-device"; prefix te-dev; /* Import TE module */ import ietf-te { prefix te; reference "RFCXXXX: A YANG Data Model for Traffic Engineering Tunnels, Label Switched Paths, and Interfaces."; } /* Import TE types */ import ietf-te-types { prefix te-types; reference "draft-ietf-teas-rfc8776-update: Common YANG Data Types for Traffic Engineering."; } import ietf-interfaces { prefix if; reference "RFC8343: A YANG Data Model for Interface Management"; } import ietf-routing-types { prefix rt-types; reference "RFC8294: Common YANG Data Types for the Routing Area"; } organization "IETF Traffic Engineering Architecture and Signaling (TEAS) Working Group"; contact "WG Web: WG List: Editor: Tarek Saad Editor: Rakesh Gandhi Saad, et al. Expires 28 August 2026 [Page 70] Internet-Draft TE YANG Data Model February 2026 Editor: Vishnu Pavan Beeram Editor: Himanshu Shah Editor: Xufeng Liu Editor: Igor Bryskin "; description "This module defines a data model for TE device configurations, state, and RPCs. Copyright (c) 2025 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 (https://www.rfc-editor.org/info/rfcXXXX); 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 2025-02-24 { description "Initial revision for the TE device YANG module."; reference "RFCXXXX: A YANG Data Model for Traffic Engineering Tunnels and Interfaces"; } grouping lsp-device-timers { description "Device TE LSP timers configs."; leaf lsp-install-interval { type uint32; Saad, et al. Expires 28 August 2026 [Page 71] Internet-Draft TE YANG Data Model February 2026 units "seconds"; description "TE LSP installation delay time."; } leaf lsp-cleanup-interval { type uint32; units "seconds"; description "TE LSP cleanup delay time."; } leaf lsp-invalidation-interval { type uint32; units "seconds"; description "TE LSP path invalidation before taking action delay time."; } } grouping te-igp-flooding-bandwidth-config { description "Configurable items for igp flooding bandwidth threshold configuration."; leaf threshold-type { type enumeration { enum delta { description "'delta' indicates that the local system should flood IGP updates when a change in reserved bandwidth >= the specified delta occurs on the interface."; } enum threshold-crossed { description "THRESHOLD-CROSSED indicates that the local system should trigger an update (and hence flood) the reserved bandwidth when the reserved bandwidth changes such that it crosses, or becomes equal to one of the threshold values."; } } description "The type of threshold that should be used to specify the values at which bandwidth is flooded. 'delta' indicates that the local system should flood IGP updates when a change in reserved bandwidth >= the specified delta occurs on the interface. Where 'threshold-crossed' is specified, the local system should trigger an update (and hence flood) the reserved bandwidth when the reserved bandwidth changes such Saad, et al. Expires 28 August 2026 [Page 72] Internet-Draft TE YANG Data Model February 2026 that it crosses, or becomes equal to one of the threshold values."; } leaf delta-percentage { when "../threshold-type = 'delta'" { description "The percentage delta can only be specified when the threshold type is specified to be a percentage delta of the reserved bandwidth."; } type rt-types:percentage; description "The percentage of the maximum-reservable-bandwidth considered as the delta that results in an IGP update being flooded."; } leaf threshold-specification { when "../threshold-type = 'threshold-crossed'" { description "The selection of whether mirrored or separate threshold values are to be used requires user-specified thresholds to be set."; } type enumeration { enum mirrored-up-down { description "mirrored-up-down indicates that a single set of threshold values should be used for both increasing and decreasing bandwidth when determining whether to trigger updated bandwidth values to be flooded in the IGP TE extensions."; } enum separate-up-down { description "separate-up-down indicates that a separate threshold values should be used for the increasing and decreasing bandwidth when determining whether to trigger updated bandwidth values to be flooded in the IGP TE extensions."; } } description "This value specifies whether a single set of threshold values should be used for both increasing and decreasing bandwidth when determining whether to trigger updated bandwidth values to be flooded in the IGP TE extensions. 'mirrored-up-down' indicates that a single value (or set of values) should be used for both increasing and decreasing Saad, et al. Expires 28 August 2026 [Page 73] Internet-Draft TE YANG Data Model February 2026 values, where 'separate-up-down' specifies that the increasing and decreasing values will be separately specified."; } leaf-list up-thresholds { when "../threshold-type = 'threshold-crossed'" + "and ../threshold-specification = 'separate-up-down'" { description "A list of up-thresholds can only be specified when the bandwidth update is triggered based on crossing a threshold and separate up and down thresholds are required."; } type rt-types:percentage; description "The thresholds (expressed as a percentage of the maximum reservable bandwidth) at which bandwidth updates are to be triggered when the bandwidth is increasing."; } leaf-list down-thresholds { when "../threshold-type = 'threshold-crossed'" + "and ../threshold-specification = 'separate-up-down'" { description "A list of down-thresholds can only be specified when the bandwidth update is triggered based on crossing a threshold and separate up and down thresholds are required."; } type rt-types:percentage; description "The thresholds (expressed as a percentage of the maximum reservable bandwidth) at which bandwidth updates are to be triggered when the bandwidth is decreasing."; } leaf-list up-down-thresholds { when "../threshold-type = 'threshold-crossed'" + "and ../threshold-specification = 'mirrored-up-down'" { description "A list of thresholds corresponding to both increasing and decreasing bandwidths can be specified only when an update is triggered based on crossing a threshold, and the same up and down thresholds are required."; } type rt-types:percentage; description "The thresholds (expressed as a percentage of the maximum reservable bandwidth of the interface) at which bandwidth updates are flooded - used both when the bandwidth is Saad, et al. Expires 28 August 2026 [Page 74] Internet-Draft TE YANG Data Model February 2026 increasing and decreasing."; } } /** * TE device augmentations */ augment "/te:te" { description "TE global container."; /* TE Interface Configuration Data */ container interfaces { description "Configuration data model for TE interfaces."; uses te-igp-flooding-bandwidth-config; list interface { key "name"; description "The list of interfaces enabled for TE."; leaf name { type if:interface-ref; description "The reference to interface enabled for TE."; } /* TE interface parameters */ leaf te-metric { type te-types:te-metric; description "TE interface metric."; } choice admin-group-type { description "TE interface administrative groups representation type."; case value-admin-groups { choice value-admin-group-type { description "The type of admin-groups."; case admin-groups { description "Administrative group/Resource class."; leaf admin-group { type te-types:admin-group; description "TE interface administrative group."; } } Saad, et al. Expires 28 August 2026 [Page 75] Internet-Draft TE YANG Data Model February 2026 case extended-admin-groups { if-feature "te-types:extended-admin-groups"; description "Extended administrative group/Resource class."; leaf extended-admin-group { type te-types:extended-admin-group; description "TE interface extended administrative group."; } } } } case named-admin-groups { list named-admin-groups { if-feature "te-types:extended-admin-groups"; if-feature "te-types:named-extended-admin-groups"; key "named-admin-group"; description "A list of named admin-group entries."; leaf named-admin-group { type leafref { path "../../../../te:globals/" + "te:named-admin-groups/te:named-admin-group/" + "te:name"; } description "A named admin-group entry."; } } } } choice srlg-type { description "Choice of SRLG configuration."; case value-srlgs { list values { key "value"; description "List of SRLG values that this link is part of."; leaf value { type uint32 { range "0..4294967295"; } description "Value of the SRLG"; } Saad, et al. Expires 28 August 2026 [Page 76] Internet-Draft TE YANG Data Model February 2026 } } case named-srlgs { list named-srlgs { if-feature "te-types:named-srlg-groups"; key "named-srlg"; description "A list of named SRLG entries."; leaf named-srlg { type leafref { path "../../../../te:globals/" + "te:named-srlgs/te:named-srlg/te:name"; } description "A named SRLG entry."; } } } } uses te-igp-flooding-bandwidth-config; list switching-capabilities { key "switching-capability"; description "List of interface capabilities for this interface."; leaf switching-capability { type identityref { base te-types:switching-capabilities; } description "Switching Capability for this interface."; } leaf encoding { type identityref { base te-types:lsp-encoding-types; } description "Encoding supported by this interface."; } } container te-advertisements-state { config false; description "TE interface advertisements state container."; leaf flood-interval { type uint32; description "The periodic flooding interval."; } Saad, et al. Expires 28 August 2026 [Page 77] Internet-Draft TE YANG Data Model February 2026 leaf last-flooded-time { type uint32; units "seconds"; description "Time elapsed since last flooding in seconds."; } leaf next-flooded-time { type uint32; units "seconds"; description "Time remained for next flooding in seconds."; } leaf last-flooded-trigger { type enumeration { enum link-up { description "Link-up flooding trigger."; } enum link-down { description "Link-down flooding trigger."; } enum threshold-up { description "Bandwidth reservation up threshold."; } enum threshold-down { description "Bandwidth reservation down threshold."; } enum bandwidth-change { description "Bandwidth capacity change."; } enum user-initiated { description "Initiated by user."; } enum srlg-change { description "SRLG property change."; } enum periodic-timer { description "Periodic timer expired."; } } default "periodic-timer"; Saad, et al. Expires 28 August 2026 [Page 78] Internet-Draft TE YANG Data Model February 2026 description "Trigger for the last flood."; } list advertised-level-areas { key "level-area"; description "List of level-areas that the TE interface is advertised in."; leaf level-area { type uint32; description "The IGP area or level where the TE interface link state is advertised in."; } } } } } } /* TE globals device augmentation */ augment "/te:te/te:globals" { description "Global TE device specific configuration parameters."; uses lsp-device-timers; } /* TE tunnels device configuration augmentation */ augment "/te:te/te:tunnels/te:tunnel" { description "Tunnel device dependent augmentation."; leaf path-invalidation-action { type identityref { base te-types:path-invalidation-action-type; } description "Tunnel path invalidation action."; } uses lsp-device-timers; } /* TE LSPs device state augmentation */ augment "/te:te/te:lsps/te:lsp" { description "TE LSP device dependent augmentation."; Saad, et al. Expires 28 August 2026 [Page 79] Internet-Draft TE YANG Data Model February 2026 container lsp-timers { when "../te:origin-type = 'ingress'" { description "Applicable to ingress LSPs only."; } description "Ingress LSP timers."; leaf uptime { type uint32; units "seconds"; description "The LSP uptime."; } leaf time-to-install { type uint32; units "seconds"; description "The time remaining for a new LSP to be instantiated in forwarding to carry traffic."; } leaf time-to-destroy { type uint32; units "seconds"; description "The time remaining for an existing LSP to be torn down."; } } container downstream-info { when "../te:origin-type != 'egress'" { description "Downstream information of the LSP."; } description "Downstream information."; leaf nhop { type te-types:te-tp-id; description "Downstream next-hop address."; } leaf outgoing-interface { type if:interface-ref; description "Downstream interface."; } container neighbor { uses te-types:te-generic-node-id; description "Downstream neighbor address."; Saad, et al. Expires 28 August 2026 [Page 80] Internet-Draft TE YANG Data Model February 2026 } leaf label { type rt-types:generalized-label; description "Downstream label."; } } container upstream-info { when "../te:origin-type != 'ingress'" { description "Upstream information of the LSP."; } description "Upstream information."; leaf phop { type te-types:te-tp-id; description "Upstream next-hop or previous-hop address."; } container neighbor { uses te-types:te-generic-node-id; description "Upstream neighbor address."; } leaf label { type rt-types:generalized-label; description "Upstream label."; } } } /* TE interfaces RPCs/execution Data */ rpc link-state-update { description "Triggers a link state update for the specific interface."; input { choice filter-type { mandatory true; description "Filter choice."; case match-all { leaf all { type empty; mandatory true; description "Match all TE interfaces."; Saad, et al. Expires 28 August 2026 [Page 81] Internet-Draft TE YANG Data Model February 2026 } } case match-one-interface { leaf interface { type if:interface-ref; description "Match a specific TE interface."; } } } } } } 7. Notifications Notifications are a key component of any topology data model. [RFC8639] and [RFC8641] define a subscription mechanism and a push mechanism for YANG datastores. These mechanisms currently allow the user to: * Subscribe to notifications on a per-client basis. * Specify subtree filters or XML Path Language (XPath) filters so that only contents of interest will be sent. * Specify either periodic or on-demand notifications. 8. IANA Considerations This document registers the following URIs in the IETF XML registry [RFC3688]. Following the format in [RFC3688], the following registrations are requested to be made. URI: urn:ietf:params:xml:ns:yang:ietf-te Registrant Contact: The IESG. XML: N/A, the requested URI is an XML namespace. URI: urn:ietf:params:xml:ns:yang:ietf-te-device Registrant Contact: The IESG. XML: N/A, the requested URI is an XML namespace. This document registers two YANG modules in the YANG Module Names registry [RFC6020]. Saad, et al. Expires 28 August 2026 [Page 82] Internet-Draft TE YANG Data Model February 2026 Name: ietf-te Namespace: urn:ietf:params:xml:ns:yang:ietf-te Prefix: te Reference: RFCXXXX Maintained by IANA: N Name: ietf-te-device Namespace: urn:ietf:params:xml:ns:yang:ietf-te-device Prefix: te-device Reference: RFCXXXX Maintained by IANA: N 9. Security Considerations The YANG module specified in this document defines a schema for data that is designed to be accessed via YANG-based management protocols, such as NETCONF [RFC6241] and RESTCONF [RFC8040]. These YANG-based management protocols (1) have to use a secure transport layer (e.g., SSH [RFC6242], TLS [RFC8446], and QUIC [RFC9000]) and (2) have to use mutual authentication. The Network Configuration Access Control Model (NACM) [RFC8341] provides the means to restrict access for particular NETCONF or RESTCONF users to a preconfigured subset of all available NETCONF or RESTCONF 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/globals": This module specifies the global TE configurations on a device. Unauthorized access to this container could cause the device to ignore packets it should receive and process. "/te/tunnels": This list specifies the configuration and state of TE Tunnels present on the device or controller. Unauthorized access to this list could cause the device to ignore packets it should receive and process. An attacker may also use state to derive information about the network topology, and subsequently orchestrate further attacks. "/te/interfaces": This list specifies the configuration and state TE interfaces on a device. Unauthorized access to this list could cause the device to ignore packets it should receive and process. Saad, et al. Expires 28 August 2026 [Page 83] Internet-Draft TE YANG Data Model February 2026 Some of the readable data nodes in this YANG module may be considered sensitive or vulnerable in some network environments. It is thus important to control read access (e.g., via get, get-config, or notification) to these data nodes. These are the subtrees and data nodes and their sensitivity/vulnerability: "/te/lsps": this list contains information state about established LSPs in the network. An attacker can use this information to derive information about the network topology, and subsequently orchestrate further attacks. Some of the RPC operations in this YANG module may be considered sensitive or vulnerable in some network environments. It is thus important to control access to these operations. These are the operations and their sensitivity/vulnerability: "/te/tunnels-actions": using this RPC, an attacker can modify existing paths that may be carrying live traffic, and hence result in interruption to services carried over the network. "/te/tunnels-path-compute": using this RPC, an attacker can retrieve sensitive information about the network provider which can be used to orchestrate further attacks. The YANG module defines a set of identities, types, and groupings. These nodes are intended to be reused by other YANG modules. The module by itself does not expose any data nodes that are writable, data nodes that contain read-only state, or RPCs. As such, there are no additional security issues related to the YANG module that need to be considered. Modules that use the groupings that are defined in this document should identify the corresponding security considerations. For example, reusing some of these groupings will expose privacy-related information (e.g., 'node-example'). 10. Acknowledgement The authors would like to thank the members of the multivendor YANG design team who are involved in the definition of this model. The authors would like to thank Tom Petch and Adrian Farrel for reviewing and providing useful feedback about the document. The authors would also like to thank Loa Andersson, Lou Berger, Sergio Belotti, Italo Busi, Carlo Perocchio, Francesco Lazzeri, Aihua Guo, Dhruv Dhody, and Raqib Jones for providing feedback on this document. Saad, et al. Expires 28 August 2026 [Page 84] Internet-Draft TE YANG Data Model February 2026 11. Contributors Oscar Gonzalez de Dios Telefonica Email: oscar.gonzalezdedios@telefonica.com Himanshu Shah Ciena Email: hshah@ciena.com Xia Chen Huawei Technologies Email: jescia.chenxia@huawei.com Bin Wen Comcast Email: Bin_Wen@cable.comcast.com 12. References 12.1. Normative References [I-D.draft-ietf-teas-rfc8776-update] Busi, I., Guo, A., Liu, X., Saad, T., and I. Bryskin, "Common YANG Data Types for Traffic Engineering", Work in Progress, Internet-Draft, draft-ietf-teas-rfc8776-update- 22, 18 February 2026, . [ITU_G.808.1] ITU-T Recommendation G.808.1, "Generic protection switching - Linear trail and subnetwork protection", https://www.itu.int/rec/T-REC-G.808.1-201405-I , May 2014. [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V., and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001, . Saad, et al. Expires 28 August 2026 [Page 85] Internet-Draft TE YANG Data Model February 2026 [RFC3473] Berger, L., Ed., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource ReserVation Protocol- Traffic Engineering (RSVP-TE) Extensions", RFC 3473, DOI 10.17487/RFC3473, January 2003, . [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004, . [RFC4206] Kompella, K. and Y. Rekhter, "Label Switched Paths (LSP) Hierarchy with Generalized Multi-Protocol Label Switching (GMPLS) Traffic Engineering (TE)", RFC 4206, DOI 10.17487/RFC4206, October 2005, . [RFC4655] Farrel, A., Vasseur, J.-P., and J. Ash, "A Path Computation Element (PCE)-Based Architecture", RFC 4655, DOI 10.17487/RFC4655, August 2006, . [RFC4872] Lang, J.P., Ed., Rekhter, Y., Ed., and D. Papadimitriou, Ed., "RSVP-TE Extensions in Support of End-to-End Generalized Multi-Protocol Label Switching (GMPLS) Recovery", RFC 4872, DOI 10.17487/RFC4872, May 2007, . [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010, . [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, . [RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011, . [RFC6780] Berger, L., Le Faucheur, F., and A. Narayanan, "RSVP ASSOCIATION Object Extensions", RFC 6780, DOI 10.17487/RFC6780, October 2012, . Saad, et al. Expires 28 August 2026 [Page 86] Internet-Draft TE YANG Data Model February 2026 [RFC7271] Ryoo, J., Ed., Gray, E., Ed., van Helvoort, H., D'Alessandro, A., Cheung, T., and E. Osborne, "MPLS Transport Profile (MPLS-TP) Linear Protection to Match the Operational Expectations of Synchronous Digital Hierarchy, Optical Transport Network, and Ethernet Transport Network Operators", RFC 7271, DOI 10.17487/RFC7271, June 2014, . [RFC7308] Osborne, E., "Extended Administrative Groups in MPLS Traffic Engineering (MPLS-TE)", RFC 7308, DOI 10.17487/RFC7308, July 2014, . [RFC7471] Giacalone, S., Ward, D., Drake, J., Atlas, A., and S. Previdi, "OSPF Traffic Engineering (TE) Metric Extensions", RFC 7471, DOI 10.17487/RFC7471, March 2015, . [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016, . [RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017, . [RFC8231] Crabbe, E., Minei, I., Medved, J., and R. Varga, "Path Computation Element Communication Protocol (PCEP) Extensions for Stateful PCE", RFC 8231, DOI 10.17487/RFC8231, September 2017, . [RFC8232] Crabbe, E., Minei, I., Medved, J., Varga, R., Zhang, X., and D. Dhody, "Optimizations of Label Switched Path State Synchronization Procedures for a Stateful PCE", RFC 8232, DOI 10.17487/RFC8232, September 2017, . [RFC8234] Ryoo, J., Cheung, T., van Helvoort, H., Busi, I., and G. Wen, "Updates to MPLS Transport Profile (MPLS-TP) Linear Protection in Automatic Protection Switching (APS) Mode", RFC 8234, DOI 10.17487/RFC8234, August 2017, . [RFC8294] Liu, X., Qu, Y., Lindem, A., Hopps, C., and L. Berger, "Common YANG Data Types for the Routing Area", RFC 8294, DOI 10.17487/RFC8294, December 2017, . Saad, et al. Expires 28 August 2026 [Page 87] Internet-Draft TE YANG Data Model February 2026 [RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018, . [RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration Access Control Model", STD 91, RFC 8341, DOI 10.17487/RFC8341, March 2018, . [RFC8343] Bjorklund, M., "A YANG Data Model for Interface Management", RFC 8343, DOI 10.17487/RFC8343, March 2018, . [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, . [RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018, . [RFC8570] Ginsberg, L., Ed., Previdi, S., Ed., Giacalone, S., Ward, D., Drake, J., and Q. Wu, "IS-IS Traffic Engineering (TE) Metric Extensions", RFC 8570, DOI 10.17487/RFC8570, March 2019, . [RFC8639] Voit, E., Clemm, A., Gonzalez Prieto, A., Nilsen-Nygaard, E., and A. Tripathy, "Subscription to YANG Notifications", RFC 8639, DOI 10.17487/RFC8639, September 2019, . [RFC8641] Clemm, A. and E. Voit, "Subscription to YANG Notifications for Datastore Updates", RFC 8641, DOI 10.17487/RFC8641, September 2019, . [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, . [RFC9000] Iyengar, J., Ed. and M. Thomson, Ed., "QUIC: A UDP-Based Multiplexed and Secure Transport", RFC 9000, DOI 10.17487/RFC9000, May 2021, . Saad, et al. Expires 28 August 2026 [Page 88] Internet-Draft TE YANG Data Model February 2026 [RFC9012] Patel, K., Van de Velde, G., Sangli, S., and J. Scudder, "The BGP Tunnel Encapsulation Attribute", RFC 9012, DOI 10.17487/RFC9012, April 2021, . [RFC9256] Filsfils, C., Talaulikar, K., Ed., Voyer, D., Bogdanov, A., and P. Mattes, "Segment Routing Policy Architecture", RFC 9256, DOI 10.17487/RFC9256, July 2022, . [RFC9911] Schönwälder, J., Ed., "Common YANG Data Types", RFC 9911, DOI 10.17487/RFC9911, December 2025, . 12.2. Informative References [rfc3473] Berger, L., Ed., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource ReserVation Protocol- Traffic Engineering (RSVP-TE) Extensions", RFC 3473, DOI 10.17487/RFC3473, January 2003, . [RFC3945] Mannie, E., Ed., "Generalized Multi-Protocol Label Switching (GMPLS) Architecture", RFC 3945, DOI 10.17487/RFC3945, October 2004, . [RFC4427] Mannie, E., Ed. and D. Papadimitriou, Ed., "Recovery (Protection and Restoration) Terminology for Generalized Multi-Protocol Label Switching (GMPLS)", RFC 4427, DOI 10.17487/RFC4427, March 2006, . [RFC4874] Lee, CY., Farrel, A., and S. De Cnodder, "Exclude Routes - Extension to Resource ReserVation Protocol-Traffic Engineering (RSVP-TE)", RFC 4874, DOI 10.17487/RFC4874, April 2007, . [RFC4875] Aggarwal, R., Ed., Papadimitriou, D., Ed., and S. Yasukawa, Ed., "Extensions to Resource Reservation Protocol - Traffic Engineering (RSVP-TE) for Point-to- Multipoint TE Label Switched Paths (LSPs)", RFC 4875, DOI 10.17487/RFC4875, May 2007, . Saad, et al. Expires 28 August 2026 [Page 89] Internet-Draft TE YANG Data Model February 2026 [RFC6107] Shiomoto, K., Ed. and A. Farrel, Ed., "Procedures for Dynamically Signaled Hierarchical Label Switched Paths", RFC 6107, DOI 10.17487/RFC6107, February 2011, . Appendix A. Data Tree Examples This section contains examples of use of the model with RESTCONF [RFC8040] and JSON encoding. For the example we will use a 4-node MPLS network where RSVP-TE MPLS Tunnels can be setup. The loopbacks of each router are shown. The network in Figure 10 will be used in the examples described in the following sections. 2001:db8::1 2001:db8::2 2001:db8::4 192.0.2.1 192.0.2.2 192.0.2.4 +-------+ +-------+ +-------+ | | | | | | | A +--------+ B +------+ D | +---+---+ +-------+ +---+---+ | | | +-------+ | | | | | +------------+ C +----------+ | | +-------+ 192.0.2.3 2001:db8::3 Figure 10: TE network used in data tree examples A.1. Basic Tunnel Setup This example uses the TE Tunnel YANG data model defined in this document to create an RSVP-TE signaled Tunnel of packet LSP encoding type. First, the TE Tunnel is created with no specific restrictions or constraints (e.g., protection or restoration). The TE Tunnel ingresses on router A and egresses on router D. In this case, the TE Tunnel is created without specifying additional information about the primary paths. Saad, et al. Expires 28 August 2026 [Page 90] Internet-Draft TE YANG Data Model February 2026 POST /restconf/data/ietf-te:te/tunnels HTTP/1.1 Host: example.com Accept: application/yang-data+json Content-Type: application/yang-data+json { "ietf-te:tunnel": [ { "name": "Example_LSP_Tunnel_A_2", "admin-state": "ietf-te-types:tunnel-admin-state-up", "encoding": "ietf-te-types:lsp-encoding-packet", "source": { "te-node-id": "192.0.2.1" }, "destination": { "te-node-id": "192.0.2.4" }, "bidirectional": false, "signaling-type": "ietf-te-types:path-setup-rsvp" } ] } { "ietf-te:tunnel": [ { "name": "Example_LSP_Tunnel_A_2 (IPv6)", "admin-state": "ietf-te-types:tunnel-admin-state-up", "encoding": "ietf-te-types:lsp-encoding-packet", "source": { "te-node-id": "2001:db8::1" }, "destination": { "te-node-id": "2001:db8::4" }, "bidirectional": false, "signaling-type": "ietf-te-types:path-setup-rsvp" } ] } A.2. Global Named Path Constraints This example uses the YANG data model to create a 'named path constraint' that can be referenced by TE Tunnels. The path constraint, in this case, limits the TE Tunnel hops for the computed path. Saad, et al. Expires 28 August 2026 [Page 91] Internet-Draft TE YANG Data Model February 2026 POST /restconf/data/ietf-te:te/globals/named-path-constraints HTTP/1.1 Host: example.com Accept: application/yang-data+json Content-Type: application/yang-data+json { "ietf-te:named-path-constraint": [ { "name": "max-hop-3", "path-metric-bounds": { "path-metric-bound": [ { "metric-type": "ietf-te-types:path-metric-hop", "upper-bound": "3" } ] } } ] } A.3. Tunnel with Global Path Constraint In this example, the previously created 'named path constraint' is applied to the TE Tunnel created in Appendix A.1. Saad, et al. Expires 28 August 2026 [Page 92] Internet-Draft TE YANG Data Model February 2026 POST /restconf/data/ietf-te:te/tunnels HTTP/1.1 Host: example.com Accept: application/yang-data+json Content-Type: application/yang-data+json { "ietf-te:tunnel": [ { "name": "Example_LSP_Tunnel_A_4_1", "description": "Simple_LSP_with_named_path", "admin-state": "ietf-te-types:tunnel-admin-state-up", "encoding": "ietf-te-types:lsp-encoding-packet", "source": { "te-node-id": "192.0.2.1" }, "destination": { "te-node-id": "192.0.2.4" }, "signaling-type": "ietf-te-types:path-setup-rsvp", "primary-paths": { "primary-path": [ { "name": "Simple_LSP_1", "use-path-computation": true, "path-scope": "ietf-te-types:path-scope-end-to-end", "named-path-constraint": "max-hop-3" } ] } } ] } A.4. Tunnel with Per-tunnel Path Constraint In this example, the per-tunnel path constraint is explicitly indicated under the TE Tunnel created in Appendix A.1 to constrain the computed path for the tunnel. Saad, et al. Expires 28 August 2026 [Page 93] Internet-Draft TE YANG Data Model February 2026 POST /restconf/data/ietf-te:te/tunnels HTTP/1.1 Host: example.com Accept: application/yang-data+json Content-Type: application/yang-data+json { "ietf-te:tunnel": [ { "name": "Example_LSP_Tunnel_A_4_2", "admin-state": "ietf-te-types:tunnel-admin-state-up", "encoding": "ietf-te-types:lsp-encoding-packet", "source": { "te-node-id": "192.0.2.1" }, "destination": { "te-node-id": "192.0.2.4" }, "bidirectional": false, "signaling-type": "ietf-te-types:path-setup-rsvp", "primary-paths": { "primary-path": [ { "name": "path1", "path-scope": "ietf-te-types:path-scope-end-to-end", "path-metric-bounds": { "path-metric-bound": [ { "metric-type": "ietf-te-types:path-metric-hop", "upper-bound": "3" } ] } } ] } } ] } A.5. Tunnel State In this example, the 'GET' query is sent to return the state stored about the tunnel. Saad, et al. Expires 28 August 2026 [Page 94] Internet-Draft TE YANG Data Model February 2026 GET /restconf/data/ietf-te:te/tunnels + /tunnel="Example_LSP_Tunnel_A_4_1" /primary-paths/ HTTP/1.1 Host: example.com Accept: application/yang-data+json The request, with status code 200 would include, for example, the following json: Saad, et al. Expires 28 August 2026 [Page 95] Internet-Draft TE YANG Data Model February 2026 { "ietf-te:primary-path": [ { "name": "path1", "path-computation-method": "ietf-te-types:path-locally-computed", "path-scope": "ietf-te-types:path-scope-end-to-end", "computed-paths-properties": { "computed-path-properties": [ { "k-index": 1, "path-properties": { "path-route-objects": { "path-route-object": [ { "index": 1, "numbered-node-hop": { "node-id": "192.0.2.2", "hop-type": "strict" } }, { "index": 2, "numbered-node-hop": { "node-id": "192.0.2.4", "hop-type": "strict" } } ] } } } ] }, "lsps": { "lsp": [ { "node": "192.0.2.1", "lsp-id": 25356, "tunnel-name": "Example_LSP_Tunnel_A_4_1" } ] } } ] } A.6. Example TE Tunnel with Primary and Secondary Paths Saad, et al. Expires 28 August 2026 [Page 96] Internet-Draft TE YANG Data Model February 2026 +----------+ +----------+ +-|192.0.2.9 |---+ |192.0.2.10| | +----------+ | +----------+ | | | | +----------+ +----------+ +----------+ | | |192.0.2.8 |----|192.0.2.3 |-----|192.0.2.4 |----+ | +----------+ +----------+ +----------+ | | | | | +----------+ | | | |192.0.2.1 |---------+ | +----------+ +----------+ +-----------|192.0.2.5 | | | +----------+ | | +----------+ | | | +--------------|192.0.2.2 |---------------------+ | | +----------+ | | | | | +----------+ | | +----------+ |192.0.2.6 |----------------+ +-------------------|192.0.2.7 | +----------+ +----------+ Figure 11: TE network used in data tree examples Below is the state retrieved for a TE tunnel from source 192.0.2.1 to 192.0.2.5 with primary, secondary, reverse, and secondary reverse paths as shown in Figure 11. { "ietf-te:te": { "tunnels": { "tunnel": [ { "name": "example-1", "description": "Example in slide 1", "source": { "te-node-id": "192.0.2.1" }, "destination": { "te-node-id": "192.0.2.5" }, "bidirectional": true, "primary-paths": { "primary-path": [ { "name": "primary-1 (fwd)", "path-scope": "ietf-te-types:path-scope-end-to-end", "co-routed": false, "explicit-route-objects": { "route-object-include-exclude": [ Saad, et al. Expires 28 August 2026 [Page 97] Internet-Draft TE YANG Data Model February 2026 { "index": 1, "explicit-route-usage": "ietf-te-types:route-include-object", "numbered-node-hop": { "node-id": "192.0.2.2", "hop-type": "loose" } } ] }, "primary-reverse-path": { "name": "primary-2 (rev)", "path-scope": "ietf-te-types:path-scope-end-to-end", "explicit-route-objects": { "route-object-include-exclude": [ { "index": 1, "explicit-route-usage": "ietf-te-types:route-include-object", "numbered-node-hop": { "node-id": "192.0.2.3", "hop-type": "loose" } } ] }, "candidate-secondary-reverse-paths": { "candidate-secondary-reverse-path": [ { "secondary-reverse-path": "secondary-3 (rev)" }, { "secondary-reverse-path": "secondary-4 (rev)" }, { "secondary-reverse-path": "secondary-5 (rev)" } ] } }, "candidate-secondary-paths": { "candidate-secondary-path": [ { "secondary-path": "secondary-1 (fwd)" }, { "secondary-path": "secondary-2 (fwd)" Saad, et al. Expires 28 August 2026 [Page 98] Internet-Draft TE YANG Data Model February 2026 } ] } } ] }, "secondary-paths": { "secondary-path": [ { "name": "secondary-1 (fwd)", "path-scope": "ietf-te-types:path-scope-end-to-end", "explicit-route-objects": { "route-object-include-exclude": [ { "index": 1, "explicit-route-usage": "ietf-te-types:route-include-object", "numbered-node-hop": { "node-id": "192.0.2.1" } }, { "index": 2, "numbered-node-hop": { "node-id": "192.0.2.2", "hop-type": "loose" } } ] } }, { "name": "secondary-2 (fwd)", "path-scope": "ietf-te-types:path-scope-end-to-end", "explicit-route-objects": { "route-object-include-exclude": [ { "index": 1, "explicit-route-usage": "ietf-te-types:route-include-object", "numbered-node-hop": { "node-id": "192.0.2.2" } }, { "index": 2, "numbered-node-hop": { "node-id": "192.0.2.5", Saad, et al. Expires 28 August 2026 [Page 99] Internet-Draft TE YANG Data Model February 2026 "hop-type": "loose" } } ] } } ] }, "secondary-reverse-paths": { "secondary-reverse-path": [ { "name": "secondary-3 (rev)", "path-scope": "ietf-te-types:path-scope-end-to-end", "explicit-route-objects": { "route-object-include-exclude": [ { "index": 1, "explicit-route-usage": "ietf-te-types:route-include-object", "numbered-node-hop": { "node-id": "192.0.2.5" } }, { "index": 2, "numbered-node-hop": { "node-id": "192.0.2.4", "hop-type": "loose" } } ] } }, { "name": "secondary-4 (rev)", "path-scope": "ietf-te-types:path-scope-end-to-end", "explicit-route-objects": { "route-object-include-exclude": [ { "index": 1, "explicit-route-usage": "ietf-te-types:route-include-object", "numbered-node-hop": { "node-id": "192.0.2.4" } }, { "index": 2, Saad, et al. Expires 28 August 2026 [Page 100] Internet-Draft TE YANG Data Model February 2026 "numbered-node-hop": { "node-id": "192.0.2.3", "hop-type": "loose" } } ] } }, { "name": "secondary-5 (rev)", "path-scope": "ietf-te-types:path-scope-end-to-end", "explicit-route-objects": { "route-object-include-exclude": [ { "index": 1, "explicit-route-usage": "ietf-te-types:route-include-object", "numbered-node-hop": { "node-id": "192.0.2.3" } }, { "index": 2, "numbered-node-hop": { "node-id": "192.0.2.1", "hop-type": "loose" } } ] } } ] } }, { "name": "example-3", "description": "Example in slide 3", "source": { "te-node-id": "192.0.2.1" }, "destination": { "te-node-id": "192.0.2.5" }, "bidirectional": true, "primary-paths": { "primary-path": [ { "name": "primary-1 (bidir)", Saad, et al. Expires 28 August 2026 [Page 101] Internet-Draft TE YANG Data Model February 2026 "path-scope": "ietf-te-types:path-scope-end-to-end", "co-routed": true, "explicit-route-objects": { "route-object-include-exclude": [ { "index": 1, "explicit-route-usage": "ietf-te-types:route-include-object", "numbered-node-hop": { "node-id": "192.0.2.2", "hop-type": "loose" } } ] }, "primary-reverse-path": { "path-scope": "ietf-te-types:path-scope-end-to-end" }, "candidate-secondary-paths": { "candidate-secondary-path": [ { "secondary-path": "secondary-1 (bidir)" }, { "secondary-path": "secondary-2 (bidir)" } ] } } ] }, "secondary-paths": { "secondary-path": [ { "name": "secondary-1 (bidir)", "path-scope": "ietf-te-types:path-scope-end-to-end", "explicit-route-objects": { "route-object-include-exclude": [ { "index": 1, "explicit-route-usage": "ietf-te-types:route-include-object", "numbered-node-hop": { "node-id": "192.0.2.1" } }, { "index": 2, Saad, et al. Expires 28 August 2026 [Page 102] Internet-Draft TE YANG Data Model February 2026 "numbered-node-hop": { "node-id": "192.0.2.2", "hop-type": "loose" } } ] } }, { "name": "secondary-2 (bidir)", "path-scope": "ietf-te-types:path-scope-end-to-end", "explicit-route-objects": { "route-object-include-exclude": [ { "index": 1, "explicit-route-usage": "ietf-te-types:route-include-object", "numbered-node-hop": { "node-id": "192.0.2.2" } }, { "index": 2, "numbered-node-hop": { "node-id": "192.0.2.5", "hop-type": "loose" } } ] } } ] } }, { "name": "example-4", "description": "Example in slide 4", "source": { "te-node-id": "192.0.2.1" }, "destination": { "te-node-id": "192.0.2.5" }, "bidirectional": true, "primary-paths": { "primary-path": [ { "name": "primary-1 (fwd)", Saad, et al. Expires 28 August 2026 [Page 103] Internet-Draft TE YANG Data Model February 2026 "path-scope": "ietf-te-types:path-scope-end-to-end", "co-routed": true, "explicit-route-objects": { "route-object-include-exclude": [ { "index": 1, "explicit-route-usage": "ietf-te-types:route-include-object", "numbered-node-hop": { "node-id": "192.0.2.2", "hop-type": "loose" } } ] }, "primary-reverse-path": { "name": "primary-2 (rev)", "path-scope": "ietf-te-types:path-scope-end-to-end", "candidate-secondary-reverse-paths": { "candidate-secondary-reverse-path": [ { "secondary-reverse-path": "secondary-3 (rev)" }, { "secondary-reverse-path": "secondary-4 (rev)" } ] } }, "candidate-secondary-paths": { "candidate-secondary-path": [ { "secondary-path": "secondary-1 (fwd)" }, { "secondary-path": "secondary-2 (fwd)" } ] } } ] }, "secondary-paths": { "secondary-path": [ { "name": "secondary-1 (fwd)", "path-scope": "ietf-te-types:path-scope-end-to-end", "explicit-route-objects": { Saad, et al. Expires 28 August 2026 [Page 104] Internet-Draft TE YANG Data Model February 2026 "route-object-include-exclude": [ { "index": 1, "explicit-route-usage": "ietf-te-types:route-include-object", "numbered-node-hop": { "node-id": "192.0.2.1" } }, { "index": 2, "numbered-node-hop": { "node-id": "192.0.2.2", "hop-type": "loose" } } ] } }, { "name": "secondary-2 (fwd)", "path-scope": "ietf-te-types:path-scope-end-to-end", "explicit-route-objects": { "route-object-include-exclude": [ { "index": 1, "explicit-route-usage": "ietf-te-types:route-include-object", "numbered-node-hop": { "node-id": "192.0.2.2" } }, { "index": 2, "numbered-node-hop": { "node-id": "192.0.2.5", "hop-type": "loose" } } ] } } ] }, "secondary-reverse-paths": { "secondary-reverse-path": [ { "name": "secondary-3 (rev)", Saad, et al. Expires 28 August 2026 [Page 105] Internet-Draft TE YANG Data Model February 2026 "path-scope": "ietf-te-types:path-scope-end-to-end" }, { "name": "secondary-4 (rev)", "path-scope": "ietf-te-types:path-scope-end-to-end" } ] } } ] } } } A.7. Example Multi-domain TE Tunnel with Primary and Secondary Paths XXXXXXX XXX XXX XX XX X X X Domain 2 X XXXXXXX X X XXXXXXXX XXX +-----------+ +-----------+ XXX XX | 192.0.2.1 | | 192.0.2.2 | XX X +-----------+ +-----------+ X X X XXXXXX X X +-----------+ X X +-----------+ |192.0.2.100| Domain 1 X X Domain 3 |192.0.2.200| +-----------+ X XXXXXX X +-----------+ X +-----------+ +-----------+ X X | 192.0.2.3 | | 192.0.2.4 | X XX +-----------+ +-----------+ XX XXX X X XXX XXX XXXXXXX X X XXXXXXX X X X Domain 4 X XX XX XXX XXX XXXXXXX Figure 12: TE network used in the multi-domain TE Tunnel example Saad, et al. Expires 28 August 2026 [Page 106] Internet-Draft TE YANG Data Model February 2026 The following state is retrieved for a multi-domain TE tunnel, where both the primary and secondary paths consist of TE tunnel segments, as shown in Figure 12. In each domain, a TE tunnel segment is established to form the complete end-to-end TE path. The nodes (192.0.2.100) and (192.0.2.200) form the multi-domain end-to-end source and destination respectively. The nodes (192.0.2.1), (192.0.2.2), (192.0.2.3), and (192.0.2.4) act as domain border nodes and transit nodes for the end-to-end TE tunnel LSPs. { "ietf-te:te": { "tunnels": { "tunnel": [ { "name": "Example_Head_End_Tunnel_Segment", "admin-state": "ietf-te-types:tunnel-admin-state-up", "encoding": "ietf-te-types:lsp-encoding-packet", "source": { "te-node-id": "192.0.2.100" }, "bidirectional": true, "signaling-type": "ietf-te-types:path-setup-rsvp", "primary-paths": { "primary-path": [ { "name": "primary-path-1", "path-scope": "ietf-te-types:path-scope-end-to-end", "co-routed": true, "explicit-route-objects": { "route-object-include-exclude": [ { "index": 1, "explicit-route-usage": "ietf-te-types:route-include-object", "numbered-link-hop": { "link-tp-id": "192.0.2.1" } } ] }, "primary-reverse-path": { "path-scope": "ietf-te-types:path-scope-end-to-end" }, "candidate-secondary-paths": { "candidate-secondary-path": [ { "secondary-path": "secondary-path-1" } Saad, et al. Expires 28 August 2026 [Page 107] Internet-Draft TE YANG Data Model February 2026 ] } } ] }, "secondary-paths": { "secondary-path": [ { "name": "secondary-path-1", "path-scope": "ietf-te-types:path-scope-end-to-end", "explicit-route-objects": { "route-object-include-exclude": [ { "index": 1, "explicit-route-usage": "ietf-te-types:route-include-object", "numbered-link-hop": { "link-tp-id": "192.0.2.3" } } ] } } ] } }, { "name": "Example_Primary_Transit_Tunnel_Segment", "admin-state": "ietf-te-types:tunnel-admin-state-up", "encoding": "ietf-te-types:lsp-encoding-packet", "bidirectional": true, "signaling-type": "ietf-te-types:path-setup-rsvp", "primary-paths": { "primary-path": [ { "name": "primary-path-2", "path-scope": "ietf-te-types:path-scope-end-to-end", "co-routed": true, "explicit-route-objects": { "route-object-include-exclude": [ { "index": 1, "explicit-route-usage": "ietf-te-types:route-include-object", "numbered-link-hop": { "link-tp-id": "192.0.2.1" } }, Saad, et al. Expires 28 August 2026 [Page 108] Internet-Draft TE YANG Data Model February 2026 { "index": 2, "explicit-route-usage": "ietf-te-types:route-include-object", "numbered-link-hop": { "link-tp-id": "192.0.2.2" } } ] }, "primary-reverse-path": { "path-scope": "ietf-te-types:path-scope-end-to-end" } } ] } }, { "name": "Example_Secondary_Transit_Tunnel_Segment", "admin-state": "ietf-te-types:tunnel-admin-state-up", "encoding": "ietf-te-types:lsp-encoding-packet", "bidirectional": true, "signaling-type": "ietf-te-types:path-setup-rsvp", "primary-paths": { "primary-path": [ { "name": "primary-path-4", "path-scope": "ietf-te-types:path-scope-end-to-end", "co-routed": true, "primary-reverse-path": { "path-scope": "ietf-te-types:path-scope-end-to-end" }, "candidate-secondary-paths": { "candidate-secondary-path": [ { "secondary-path": "secondary-path-4" } ] } } ] }, "secondary-paths": { "secondary-path": [ { "name": "secondary-path-4", "path-scope": "ietf-te-types:path-scope-end-to-end", "explicit-route-objects": { Saad, et al. Expires 28 August 2026 [Page 109] Internet-Draft TE YANG Data Model February 2026 "route-object-include-exclude": [ { "index": 1, "explicit-route-usage": "ietf-te-types:route-include-object", "numbered-link-hop": { "link-tp-id": "192.0.2.3" } }, { "index": 2, "explicit-route-usage": "ietf-te-types:route-include-object", "numbered-link-hop": { "link-tp-id": "192.0.2.4" } } ] } } ] } }, { "name": "Example_Tail_End_Tunnel_Segment", "admin-state": "ietf-te-types:tunnel-admin-state-up", "encoding": "ietf-te-types:lsp-encoding-packet", "destination": { "te-node-id": "192.0.2.200" }, "bidirectional": true, "signaling-type": "ietf-te-types:path-setup-rsvp", "primary-paths": { "primary-path": [ { "name": "primary-path-3", "path-scope": "ietf-te-types:path-scope-end-to-end", "co-routed": true, "explicit-route-objects": { "route-object-include-exclude": [ { "index": 1, "explicit-route-usage": "ietf-te-types:route-include-object", "numbered-link-hop": { "link-tp-id": "192.0.2.2" } } Saad, et al. Expires 28 August 2026 [Page 110] Internet-Draft TE YANG Data Model February 2026 ] }, "primary-reverse-path": { "path-scope": "ietf-te-types:path-scope-end-to-end" }, "candidate-secondary-paths": { "candidate-secondary-path": [ { "secondary-path": "secondary-path-3" } ] } } ] }, "secondary-paths": { "secondary-path": [ { "name": "secondary-path-3", "path-scope": "ietf-te-types:path-scope-end-to-end", "explicit-route-objects": { "route-object-include-exclude": [ { "index": 1, "explicit-route-usage": "ietf-te-types:route-include-object", "numbered-link-hop": { "link-tp-id": "192.0.2.4" } } ] } } ] } } ] } } } Appendix B. Full Model Tree Diagram The full tree diagram of the TE YANG data model defined in module 'ietf-te' is shown below. Saad, et al. Expires 28 August 2026 [Page 111] Internet-Draft TE YANG Data Model February 2026 module: ietf-te +--rw te +--rw enable? boolean +--rw globals | +--rw named-admin-groups | | +--rw named-admin-group* [name] | | {te-types:extended-admin-groups, | | te-types:named-extended-admin-groups}? | | +--rw name string | | +--rw bit-position? uint32 | +--rw named-srlgs | | +--rw named-srlg* [name] {te-types:named-srlg-groups}? | | +--rw name string | | +--rw value? te-types:srlg | | +--rw cost? uint32 | +--rw named-path-constraints | +--rw named-path-constraint* [name] | {te-types:named-path-constraints}? | +--rw name string | +---u path-constraints-common +--rw tunnels | +--rw tunnel* [name] | +--rw name string | +--rw alias? string | +--rw identifier? uint32 | +--rw color? uint32 | +--rw description? string | +--rw admin-state? identityref | +--ro operational-state? identityref | +--rw state-change-timestamp? | | yang:date-and-time | +---u te-types:encoding-and-switching-type | +---u tunnel-common-attributes | +--rw controller | | +--rw protocol-origin? identityref | | +--rw controller-entity-id? string | +--rw reoptimize-timer? uint16 | +---u tunnel-associations-properties | +---u protection-restoration-properties | +---u te-types:tunnel-constraints | +---u tunnel-hierarchy-properties | +--rw primary-paths | | +--rw primary-path* [name] | | +--ro active? boolean | | +---u path-common-properties | | +---u path-forward-properties | | +---u k-requested-paths | | +---u path-compute-info Saad, et al. Expires 28 August 2026 [Page 112] Internet-Draft TE YANG Data Model February 2026 | | +---u path-state | | +--rw primary-reverse-path | | | +---u path-common-properties | | | +---u path-compute-info | | | +---u path-state | | | +--rw candidate-secondary-reverse-paths | | | +--rw candidate-secondary-reverse-path* | | | [secondary-reverse-path] | | | +--rw secondary-reverse-path leafref | | | +--ro active? boolean | | +--rw candidate-secondary-paths | | +--rw candidate-secondary-path* [secondary-path] | | +--rw secondary-path leafref | | +--ro active? boolean | +--rw secondary-paths | | +--rw secondary-path* [name] | | +---u path-common-properties | | +--rw preference? uint8 | | +--rw secondary-reverse-path? leafref | | +---u path-compute-info | | +---u protection-restoration-properties | | +---u path-state | +--rw secondary-reverse-paths | | +--rw secondary-reverse-path* [name] | | +---u path-common-properties | | +--rw preference? uint8 | | +---u path-compute-info | | +---u protection-restoration-properties | | +---u path-state | +---x tunnel-action | | +---w input | | | +---w action-type? identityref | | +--ro output | | +--ro action-result? identityref | +---x protection-external-commands | +---w input | +---w protection-external-command? identityref | +---w ingress-node? boolean | +---w egress-node? boolean | +---w path-name? string | +---w path-type? | | te-types:path-type | +---w traffic-type? enumeration | +---w extra-traffic-tunnel-ref? tunnel-ref +--ro lsps +--ro lsp* [tunnel-name lsp-id node] +--ro tunnel-name string +--ro lsp-id uint16 Saad, et al. Expires 28 August 2026 [Page 113] Internet-Draft TE YANG Data Model February 2026 +--ro node te-types:te-node-id +--ro source? te-types:te-node-id +--ro destination? te-types:te-node-id +--ro tunnel-id? uint16 +--ro extended-tunnel-id? yang:dotted-quad +--ro operational-state? identityref +--ro signaling-type? identityref +--ro origin-type? enumeration +--ro lsp-resource-status? enumeration +--ro lockout-of-normal? boolean +--ro freeze? boolean +--ro lsp-protection-role? enumeration +--ro lsp-protection-state? identityref +--ro ingress-node-id? te-types:te-node-id +--ro egress-node-id? te-types:te-node-id +--ro lsp-actual-route-information +--ro lsp-actual-route-information* [index] +---u te-types:record-route-state rpcs: +---x tunnels-path-compute | +---w input | | +---w path-compute-info | +--ro output | +--ro path-compute-result +---x tunnels-actions +---w input | +---w tunnel-info | | +---w (filter-type) | | +--:(all-tunnels) | | | +---w all empty | | +--:(one-tunnel) | | +---w tunnel? tunnel-ref | +---w action-info | +---w action? identityref | +---w disruptive? empty +--ro output +--ro action-result? identityref grouping path-common-properties: +-- name? string +-- path-computation-method? identityref +-- path-computation-server | +---u te-types:te-generic-node-id +-- compute-only? empty +-- use-path-computation? boolean +-- lockdown? empty +--ro path-scope? identityref Saad, et al. Expires 28 August 2026 [Page 114] Internet-Draft TE YANG Data Model February 2026 grouping path-compute-info: +---u tunnel-associations-properties +---u te-types:generic-path-optimization +-- named-path-constraint? leafref | {te-types:named-path-constraints}? +---u path-constraints-common grouping path-forward-properties: +-- preference? uint8 +-- co-routed? boolean grouping k-requested-paths: +-- k-requested-paths? uint8 grouping path-state: +---u path-computation-response +--ro lsp-provisioning-error-infos | +--ro lsp-provisioning-error-info* [] | +--ro error-reason? identityref | +--ro error-description? string | +--ro error-timestamp? yang:date-and-time | +--ro error-node-id? te-types:te-node-id | +--ro error-link-id? te-types:te-tp-id | +--ro lsp-id? uint16 +--ro lsps +--ro lsp* [node lsp-id] +--ro tunnel-name? -> /te/lsps/lsp/tunnel-name +--ro node? leafref +--ro lsp-id? leafref +--ro state-change-timestamp? yang:date-and-time grouping path-computation-response: +--ro computed-paths-properties | +--ro computed-path-properties* [k-index] | +--ro k-index? uint8 | +---u te-types:generic-path-properties +--ro computed-path-error-infos +--ro computed-path-error-info* [] +--ro error-description? string +--ro error-timestamp? yang:date-and-time +--ro error-reason? identityref grouping protection-restoration-properties: +-- protection | +-- protection-type? identityref | +-- protection-reversion-disable? boolean | +-- hold-off-time? uint32 | +-- wait-to-revert? uint16 | +-- aps-signal-id? uint8 +-- restoration +-- restoration-type? identityref +-- restoration-scheme? identityref +-- restoration-reversion-disable? boolean Saad, et al. Expires 28 August 2026 [Page 115] Internet-Draft TE YANG Data Model February 2026 +-- hold-off-time? uint32 +-- wait-to-restore? uint16 +-- wait-to-revert? uint16 grouping tunnel-associations-properties: +-- association-objects +-- association-object* [association-key] | +-- association-key? string | +-- type? identityref | +-- id? uint16 | +-- source | +---u te-types:te-generic-node-id +-- association-object-extended* [association-key] +-- association-key? string +-- type? identityref +-- id? uint16 +-- source | +---u te-types:te-generic-node-id +-- global-source? uint32 +-- extended-id? yang:hex-string grouping tunnel-end-point: +-- node-id? nw:node-id +-- te-node-id? te-types:te-node-id +-- tunnel-tp-id? binary grouping tunnel-common-attributes: +-- source | +---u tunnel-end-point +-- destination | +---u tunnel-end-point +-- bidirectional? boolean grouping tunnel-hierarchy-properties: +-- hierarchy +-- dependency-tunnels | +-- dependency-tunnel* [name] | +-- name? tunnel-ref | +---u te-types:encoding-and-switching-type +-- hierarchical-link +-- enable? boolean +-- local-node-id? nw:node-id +-- local-te-node-id? te-types:te-node-id +-- local-link-tp-id? nt:tp-id +-- local-te-link-tp-id? te-types:te-tp-id +-- remote-node-id? nw:node-id +-- remote-link-tp-id? nt:tp-id +-- remote-te-link-tp-id? te-types:te-tp-id +-- remote-te-node-id? te-types:te-node-id +--ro link-id? nt:link-id +-- network-id? nw:network-id +---u te-types:te-topology-identifier Saad, et al. Expires 28 August 2026 [Page 116] Internet-Draft TE YANG Data Model February 2026 grouping path-constraints-common: +---u te-types:common-path-constraints-attributes +---u te-types:generic-path-disjointness +---u te-types:path-constraints-route-objects +-- path-in-segment! | +---u te-types:label-set-info +-- path-out-segment! +---u te-types:label-set-info Authors' Addresses Tarek Saad Cisco Systems Inc Email: tsaad.net@gmail.com Rakesh Gandhi Cisco Systems Inc Email: rgandhi@cisco.com Xufeng Liu Alef Edge Email: xufeng.liu.ietf@gmail.com Vishnu Pavan Beeram Juniper Networks Email: vbeeram@juniper.net Igor Bryskin Individual Email: i_bryskin@yahoo.com Saad, et al. Expires 28 August 2026 [Page 117]