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A YANG Data Model for Network Hardware Inventory
draft-ietf-ccamp-network-inventory-yang-01

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This is an older version of an Internet-Draft whose latest revision state is "Expired".
Authors Chaode Yu , Sergio Belotti , Jean-Francois Bouquier , Fabio Peruzzini , Phil Bedard
Last updated 2023-03-12
Replaces draft-yg3bp-ccamp-network-inventory-yang
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draft-ietf-ccamp-network-inventory-yang-01
CCAMP Working Group                                                C. Yu
Internet-Draft                                       Huawei Technologies
Intended status: Standards Track                              S. Belotti
Expires: 11 September 2023                                         Nokia
                                                          J.-F. Bouquier
                                                                Vodafone
                                                            F. Peruzzini
                                                                     TIM
                                                               P. Bedard
                                                                   Cisco
                                                           10 March 2023

            A YANG Data Model for Network Hardware Inventory
               draft-ietf-ccamp-network-inventory-yang-01

Abstract

   This document defines a YANG data model for network hardware
   inventory data information.

   The YANG data model presented in this document is intended to be used
   as the basis toward a generic YANG data model for network hardware
   inventory data information which can be augmented, when required,
   with technology-specific (e.g., optical) inventory data, to be
   defined either in a future version of this document or in another
   document.

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

Status of This Memo

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

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on 11 September 2023.

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Copyright Notice

   Copyright (c) 2023 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents (https://trustee.ietf.org/
   license-info) in effect on the date of publication of this document.
   Please review these documents carefully, as they describe your rights
   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
     1.1.  Terminology and Notations . . . . . . . . . . . . . . . .   4
     1.2.  Requirements Notation . . . . . . . . . . . . . . . . . .   6
     1.3.  Tree Diagram  . . . . . . . . . . . . . . . . . . . . . .   6
     1.4.  Prefix in Data Node Names . . . . . . . . . . . . . . . .   6
   2.  YANG Data Model for Network Hardware Inventory  . . . . . . .   6
     2.1.  YANG Model Overview . . . . . . . . . . . . . . . . . . .   7
       2.1.1.  Common Design for All Inventory Objects . . . . . . .   9
       2.1.2.  Reference from RFC8348  . . . . . . . . . . . . . . .  10
       2.1.3.  Changes with respect to RFC8348 . . . . . . . . . . .  11
       2.1.4.  Equipment Room  . . . . . . . . . . . . . . . . . . .  13
       2.1.5.  Rack  . . . . . . . . . . . . . . . . . . . . . . . .  13
       2.1.6.  Network Element . . . . . . . . . . . . . . . . . . .  15
       2.1.7.  Relationship between Hardware Inventory and Network
               Topology models . . . . . . . . . . . . . . . . . . .  15
     2.2.  Efficiency Issue  . . . . . . . . . . . . . . . . . . . .  17
     2.3.  Some Other Considerations . . . . . . . . . . . . . . . .  18
   3.  Tree Diagrams . . . . . . . . . . . . . . . . . . . . . . . .  18
     3.1.  Network Hardware Inventory Tree Diagram . . . . . . . . .  18
     3.2.  Relationship between Topology and Network Inventory Tree
           Diagram . . . . . . . . . . . . . . . . . . . . . . . . .  20
   4.  YANG Data Models  . . . . . . . . . . . . . . . . . . . . . .  20
     4.1.  YANG Data Model for Network Hardware Inventory  . . . . .  20
     4.2.  YANG Data Model for Relationship between Topology and
           Network Inventory . . . . . . . . . . . . . . . . . . . .  33
   5.  Manageability Considerations  . . . . . . . . . . . . . . . .  36
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  36
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  36
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  36
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .  36
     8.2.  Informative References  . . . . . . . . . . . . . . . . .  37
   Appendix A.  Appendix . . . . . . . . . . . . . . . . . . . . . .  38

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     A.1.  Comparison With Openconfig-platform Data Model  . . . . .  38
   Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . .  41
   Contributors  . . . . . . . . . . . . . . . . . . . . . . . . . .  41
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  42

1.  Introduction

   Network hardware inventory management is a key component in
   operators' OSS architectures.

   Network hardware inventory is a fundamental functionality in network
   management and was specified many years ago.  Given the emergence of
   data models and their deployment in operator's management and control
   systems, the traditional function of inventory management is also
   requested to be defined as a data model.

   Network hardware inventory management and monitoring is a critical
   part for ensuring the network stays healthy, well-planned, and
   functioning in the operator's network.  Network hardware inventory
   management allows the operator to keep track of which physical
   devices are deployed in the network including relevant software and
   hardware versions.

   The network hardware inventory management also helps the operator to
   know when to acquire new assets and what is needed, or to
   decommission old or faulty ones, which can help to improve network
   performance and capacity planning.

   In [I-D.ietf-teas-actn-poi-applicability] a gap was identified
   regarding the lack of a YANG data model that could be used at ACTN
   MPI interface level to report whole/partial network hardware
   inventory information available at domain controller level towards
   north-bound systems (e.g., MDSC or OSS layer).

   [RFC8345] initial goal was to make possible the augmentation of the
   YANG data model with network hardware inventory data model but this
   was never developed and the scope was kept limited to network
   topology data only.

   It is key for operators to drive the industry towards the use of a
   standard YANG data model for network hardware inventory data instead
   of using vendors proprietary APIs (e.g., REST API).

   In the ACTN architecture, this would bring also clear benefits at
   MDSC level for packet over optical integration scenarios since this
   would enable the correlation of the inventory information with the
   links information reported in the network topology model.

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   The intention is to define a generic YANG data model that would be as
   much as possible technology agnostic (valid for IP, optical and
   microwave networks) and that could be augmented, when required, to
   include some technology-specific inventory details.

   [RFC8348] defines a YANG data model for the management of the
   hardware on a single server and therefore it is more applicable to
   the domain controller South Bound Interface (SBI) towards the network
   elements rather than at the domain controller's northbound.  However,
   the YANG data model defined in [RFC8348] has been used as a reference
   for defining the YANG network hardware inventory data model presented
   in this draft.

   For optical network hardware inventory, the network hardware
   inventory YANG data model should support the use cases (4a and 4b)
   and requirements as defined in [ONF_TR-547], in order to guarantee a
   seamless integration at MDSC/OSS/orchestration layers.

   The proposed YANG data model has been analysed at the present stage
   to cover the requirements and use cases for Optical Network Hardware
   Inventory.

   Being based on [RFC8348], this data model should be a good starting
   point toward a generic data model and applicable to any technology.
   However, further analysis of requirements and use cases is needed to
   extend the applicability of this YANG data model to other types of
   networks (IP and microwave) and to identify which aspects are generic
   and which aspects are technology-specific for optical networks.

   This document defines two YANG modules: "ietf-network-hardware-
   inventory", defined in Section 4.1, and "ietf-hw-inventory-ref-topo",
   defined in Section 4.2.

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

1.1.  Terminology and Notations

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

   *  client

   *  server

   *  augment

   *  data model

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   *  data node

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

   *  configuration data

   *  state data

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

   TBD: Recap the concept of chassis/slot/component/board/... in
   [TMF_SD2-20].

   Following terms are used for the representation of the hierarchies in
   the network hardware inventory.

   Network Element:

      a device installed on one or several chassis and can afford some
      specific transmission function independently.

   Rack:

      a holder of the device and provides power supply for the device in
      it.

   Chassis:

      a holder of the device installation.

   Slot:

      a holder of the board.

   Component:

      holders and equipment of the network element, including chassis,
      slot, sub-slot, board and port.

   Board/Card:

      a pluggable equipment can be inserted into one or several slots/
      sub-slots and can afford a specific transmission function
      independently.

   Port:

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      an interface on board

1.2.  Requirements Notation

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

1.3.  Tree Diagram

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

1.4.  Prefix in Data Node Names

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

        +========+=================================+=============+
        | Prefix | Yang Module                     | Reference   |
        +========+=================================+=============+
        | inet   | ietf-inet-types                 | [RFC6991]   |
        +--------+---------------------------------+-------------+
        | yang   | ietf-yang-types                 | [RFC6991]   |
        +--------+---------------------------------+-------------+
        | ianahw | iana-hardware                   | [IANA_YANG] |
        +--------+---------------------------------+-------------+
        | ni     | ietf-network-hardware-inventory | RFC XXXX    |
        +--------+---------------------------------+-------------+
        | hirt   | ietf-hw-inventory-ref-topo      | RFC XXXX    |
        +--------+---------------------------------+-------------+

             Table 1: Prefixes and corresponding YANG modules

   RFC Editor Note: Please replace XXXX with the RFC number assigned to
   this document.  Please remove this note.

2.  YANG Data Model for Network Hardware Inventory

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2.1.  YANG Model Overview

   Based on TMF classification in [TMF_SD2-20], inventory objects can be
   divided into two groups, holder group and equipment group.  The
   holder group contains rack, chassis, slot, sub-slot while the
   equipment group contains network-element, board and port.  With the
   requirement of GIS and on-demand domain controller selection raised,
   the equipment room becomes a new inventory object to be managed
   besides TMF classification.

   Logically, the relationship between these inventory objects can be
   described by Figure 1 below:

                   +-------------+
                   |  inventory  |
                   +-------------+
                       // \\
                 1:N  //   \\ 1:M
                     //     \\
     +----------------+     +-----------------+
     | equipment room |     | network element |
     +----------------+     +-----------------+
             ||                     ||
             || 1:N                 ||
             \/                     ||
       +------------+               ||1:M
       |    rack    |               ||
       +------------+               ||
             ||                     ||
             || 1:N                 \/
             ||______________\+------------+
             |---------------/|   chassis  |
                              +------------+
                                    ||
                     ______1:N______||_____1:M_______
                     ||------------------ ---------||
                     \/                            \/
              +--------------+               +-----------+
              | slot/subslot |               |   board   |
              +--------------+               +-----------+
                                                   ||
                                                   ||1:N
                                                   \/
                                             +-----------+
                                             |    port   |
                                             +-----------+

              Figure 1: Relationship between inventory objects

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   In [RFC8348], rack, chassis, slot, sub-slot, board and port are
   defined as components of network elements with generic attributes.

   Considering there are some special scenarios, there is no direct
   relationship between the rack and network element.  In some cases,
   one network element contains multiple racks while in other cases one
   rack contains several shelves belonging to one or more network
   elements.

   While [RFC8348] is used to manage the hardware of a single server
   (e.g., a network element), the Network Hardware Inventory YANG data
   model is used to retrieve the network hardware inventory information
   that a controller discovers from all the network elements under its
   control.

   However, the YANG data model defined in [RFC8348] has been used as a
   reference for defining the YANG network hardware inventory data
   model.  This approach can simplify the implementation of this network
   hardware inventory model when the controller uses the YANG data model
   defined in [RFC8348] to retrieve the hardware from the network
   elements under its control.

   Note: review in future versions of this document whether to re-use
   definitions from [RFC8348] or use schema-mount.

     +--ro network-hardware-inventory
        +--ro equipment-rooms
        |  +--ro equipment-room* [uuid]
        |     +--ro uuid        yang:uuid
        |     ...................................
        |     +--ro racks
        |        +--ro rack* [uuid]
        |           +--ro uuid           yang:uuid
        |           ...................................
        |           +--ro contained-chassis* [ne-ref component-ref]
        |              +--ro ne-ref?          leafref
        |              +--ro component-ref?   leafref
        +--ro network-elements
           +--ro network-element* [uuid]
              +--ro uuid          yang:uuid
              ...................................
              +--ro components
                 +--ro component* [uuid]
                    +--ro uuid              yang:uuid
                    ...................................

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2.1.1.  Common Design for All Inventory Objects

   For all the inventory objects, there are some common attributes
   existing.  Such as:

   Identifier: here we suggest to use uuid format which is widely
   implemented with systems.  It is guaranteed to be globally unique.

   Name: name is a human-readable label information which could be used
   to present on GUI.  This name is suggested to be provided by server.

   Alias: alias is also a human-readable label information which could
   be modified by user.  It could also be present on GUI instead of
   name.

   Description: description is a human-readable information which could
   be also input by user.  Description provides more detailed
   information to prompt users when performing maintenance operations.

   Location: location is a common management requirement of operators.
   This location could be an absolute position (e.g. mailing address),
   or a relative position (e.g. port index).  Different types of
   inventory objects may require different types of position.

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   module: ietf-network-hardware-inventory
      +--ro network-hardware-inventory
         +--ro equipment-rooms
         |  +--ro equipment-room* [uuid]
         |     +--ro uuid           yang:uuid
         |     +--ro name?          string
         |     +--ro description?   string
         |     +--ro alias?         string
         |     +--ro location?      string
         |     ...................................
         |     +--ro racks
         |        +--ro rack* [uuid]
         |           +--ro uuid                 yang:uuid
         |           +--ro name?                string
         |           +--ro description?         string
         |           +--ro alias?               string
         |           +--ro rack-location
         |           |  +--ro equipment-room-name?   leafref
         |           |  +--ro row-number?            uint32
         |           |  +--ro column-number?         uint32
         |           ...................................
         +--ro network-elements
            +--ro network-element* [uuid]
               +--ro uuid             yang:uuid
               +--ro name?            string
               +--ro description?     string
               +--ro alias?           string
               +--ro ne-location
               |  +--ro equipment-room-name*   leafref
               ...................................
               +--ro components
                  +--ro component* [uuid]
                     +--ro uuid                     yang:uuid
                     +--ro name?                    string
                     +--ro description?             string
                     +--ro alias?                   string
                     +--ro location                 string
                     ...................................

2.1.2.  Reference from RFC8348

   The YANG data model for network hardware inventory mainly follows the
   same approach of [RFC8348] and reports the network hardware inventory
   as a list of components with different types (e.g., chassis, module,
   port).

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     +--ro components
        +--ro component* [uuid]
           +--ro uuid              yang:uuid
           +--ro name?             string
           +--ro description?      string
           +--ro class?            identityref
           +--ro contained-child*  -> ../uuid
           +--ro hardware-rev?     string
           +--ro firmware-rev?     string
           +--ro software-rev?     string
           +--ro serial-num?       string
           +--ro mfg-name?         string
           +--ro asset-id?         string
           +--ro is-fru?           boolean
           +--ro mfg-date?         yang:date-and-time
           +--ro uri*              inet:uri

   Some of the definitions taken from [RFC8348] are actually based on
   the ENTITY-MIB [RFC6933].

   For state data like admin-state, oper-state and so on, we consider
   they are related to device hardware management and not hardware
   inventory.  Therefore, they are outside of scope of this document.
   Same for the sensor-data, they should be defined in some other
   performance monitoring data models instead of inventory data model.

   We re-defined some attributes listed in [RFC8348], based on some
   integration experience for network wide inventory data.

2.1.3.  Changes with respect to RFC8348

2.1.3.1.  New Parent Identifiers' Reference

   [RFC8348] provided a "parent-ref" attribute, which was an identifier
   reference to its parent component.  When the MDSC or OSS systems want
   to find this component's grandparent or higher level component in the
   hierarchy, they need to retrieve this parent-ref step by step.  To
   reduce this iterative work, we decided to provide a list of
   hierarchical parent components' identifier references.

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     +--ro components
        +--ro component* [uuid]
           ...................................
           +--ro parent-references
           |  +--ro equipment-room-uuid?    leafref
           |  +--ro ne-uuid?                leafref
           |  +--ro rack-uuid?              leafref
           |  +--ro component-references
           |     +--ro component-reference* [index]
           |        +--ro index    uint8
           |        +--ro class?   leafref
           |        +--ro uuid?    leafref
           ...................................

   The hierarchical components' identifier could be found by the
   "component-reference" list.  The "index" attribute is used to order
   the list by the hierarchical relationship from topmost component
   (with the "index" set to 0) to bottom component.

2.1.3.2.  Component-Specific Info Design

   According to the management requirements from operators, some
   important attributes are not defined in [RFC8348].  These attributes
   could be component-specific and are not suitable to define under the
   component list node.  So, we defined a choice-case structure for this
   component-specific extension, as follows:

     +--ro components
        +--ro component* [uuid]
           ...................................
           +--ro (component-class)?
              +--:(chassis)
              |  +--ro chassis-specific-info
              +--:(container)
              |  +--ro slot-specific-info
              +--:(module)
              |  +--ro board-specific-info
              +--:(port)
                 +--ro port-specific-info
           ...................................

   Note: The detail of each *-specific-info YANG container is still
   under discussion, and the leaf attributes will be defined in future.

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2.1.3.3.  Part Number

   According to the description in [RFC8348], the attribute named
   "model-name" under the component, is preferred to have a customer-
   visible part number value.  "Model-name" is not straightforward to
   understand and we suggest to rename it as "part-number" directly.

     +--ro components
        +--ro component* [uuid]
           ...................................
           +--ro part-number?           string
           ...................................

2.1.4.  Equipment Room

   Note: add some more attributes about equipment room in the future.

2.1.5.  Rack

   Besides the common attributes mentioned in above section, rack could
   have some specific attributes, such as appearance-related attributes
   and electricity-related attributes.  The height, depth and width are
   described by the figure below (please consider that the door of the
   rack is facing the user):

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                    ----------------      ---
                   /|              /|      |
                  / |             / |      |
                 /  |            /  |      |
                ----|-----------|   |      |
                |   |           |   |      |
                |   |           |   |      |
                |   |           |   |      |
                |   |           |   |      |
                |   |           |   |      |
                |   |           |   |    height
                |   |           |   |      |
                |   |           |   |      |
                |   |           |   |      |
                |   | Door    Q |   |      |
                |   |         Q |   |      |
                |   |           |   |      |
                |   |           |   |      |
                |   |           |   |      |
                |   |           |   |      |
                |   |           |   |      |
                |   |           |   |      |
                |   |           |   |      |
                |   /-----------|----     ---
                |  /            |   /      /
                | /             |  /      depth
                |/              | /      /
                -----------------      ---
                |______width____|
                |               |

                 Figure 2: height, width and depth of rack

   The rack attributes include:

      +--ro racks
         +--ro rack* [uuid]
            ...................................
            +--ro height?              uint16
            +--ro width?               uint16
            +--ro depth?               uint16
            +--ro max-voltage?         uint16
            ...................................

   Max-voltage: the maximum voltage supported by the rack.

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2.1.6.  Network Element

   We consider that some of the attributes defined in [RFC8348] for
   components are also applicable for network element.  These attributes
   include:

         +--ro network-elements
            +--ro network-element* [uuid]
               ...................................
               +--ro hardware-rev?    string
               +--ro firmware-rev?    string
               +--ro software-rev?    string
               +--ro mfg-name?        string
               +--ro mfg-date?        yang:date-and-time
               +--ro part-number?     string
               +--ro serial-number?   string
               +--ro product-name?    string
               ...................................

   Note: Not all the attributes defined in [RFC8348] are applicable for
   network element.  And there could also be some missing attributes
   which are not recognized by [RFC8348].  More extensions could be
   introduced in later revisions after the missing attributes are fully
   discussed.

2.1.7.  Relationship between Hardware Inventory and Network Topology
        models

   Network topology is a logical abstraction based on hardware inventory
   objects.  The abstraction may be based on technology requirements
   (e.g., layer 0 or layer 1 resources) or on some specific requirements
   (e.g., for path computation or service provisioning).

   Therefore the relationship between hardware inventory objects and
   network topology objects can be 1:N (N>=1).

   Taking the Optical technology as example, an Optical Transport
   Network (OTN) Network Element (NE) can be installed with several
   kinds of boards, including an Ethernet client signal switching board,
   a line board which is used for OTN layer switching.  This line board
   may also be used as a starting point for the WDM layer.  In terms of
   technologies, this OTN NE supports multi-layer network topology
   connections, so that it should appear in L0, L1 and L2 network
   topology.

   It is important to describe this relationship for the sake of network
   Operation and Maintenance (O&M).  For example, the actual path of a
   connection is described by the objects in network topology.  When

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   there is a failure along this connection, the O&M engineers are more
   concerned with the physical location information behind the network
   objects for troubleshooting.

   Generally speaking, a node object in the network topology corresponds
   to a network element object in the hardware inventory.  A Link
   Termination Point (LTP) object in the network topology corresponds to
   a port component in the hardware inventory.  A link object in the
   network topology corresponds to a fiber/cable object in the hardware
   inventory.

   NOTE: take fiber&cable object into scope in the future version.

   Compared with network topology, hardware inventory objects are the
   most basic of the network: from an automation perspective, the MDSC
   or OSS systems would integrate with hardware inventory data before
   network topology data.

   Therefore it is better to keep separated the network topology
   information and the hardware inventory information: the "ietf-hw-
   inventory-ref-topo" YANG module provides this relationship augmenting
   the network topology model, when required, with references between
   network topology objects and corresponding hardware inventory
   objects.

   This figure below shows the relationship between the three modules:

        +------------------+
        | Network topology |
        |      module      |
        +------------------+
                ^
                |
                |augments
                |
        +------------------+          +------------------+
        | ietf-hw-inventory| imports  | ietf-network-hard|
        |   -ref-topo      |--------> |  ware-inventory  |
        +------------------+          +------------------+

           Figure 3: Relationship between the three YANG modules

   module: ietf-hw-inventory-ref-topo
   augment /nw:networks/nw:network/nw:node:
      +--ro inventory-id?   leafref
   augment /nw:networks/nw:network/nw:node/nt:termination-point:
      +--ro inventory-id?   leafref

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   NOTE: the association between a link and a fiber&cable object has to
   be added in the future version.

2.2.  Efficiency Issue

   During the integration with OSS in some operators, some efficiency/
   scalability concerns have been discovered when synchronizing network
   hardware inventory data for big networks.  More discussions are
   needed to address these concerns.

   Considering that relational databases are widely used by traditional
   OSS systems and also by some network controllers, the inventory
   objects are most likely to be saved in different tables.  With the
   model defined in current draft, when doing a full synchronization,
   network controller needs to convert all inventory objects of each NE
   into component objects and combine them together into a single list,
   and then construct a response and send to OSS or MDSC.  The OSS or
   MDSC needs to classify the component list and divide them into
   different groups, in order to save them in different tables.  The
   combining-regrouping steps are impacting the network controller &
   OSS/MDSC processing, which may result in efficiency/scalability
   limitations in large scale networks.

   An alternative YANG model structure, which defines the inventory
   objects directly, instead of defining generic components, has also
   been analyzed.  However, also with this model, there still could be
   some scalability limitations when synchronizing full inventory
   resources in large scale of networks.  This scalability limitation is
   caused by the limited transmission capabilities of HTTP protocol.  We
   think that this scalability limitation should be solved at protocol
   level rather than data model level.

   The model proposed by this draft is designed to be as generic as
   possible so to cover future special types of inventory objects that
   could be used in other technologies, that have not been identified
   yet.  If the inventory objects were to be defined directly with fixed
   hierarchical relationships in YANG model, this new type of inventory
   objects needs to be manually defined, which is not a backward
   compatible change and therefore is not an acceptable approach for
   implementation.  With a generic model, it is only needed to augment a
   new component class and extend some specific attributes for this new
   inventory component class, which is more flexible.  We consider that
   this generic data model, enabling a flexible and backward compatible
   approach for other technologies, represents the main scope of this
   draft.  Solution description to efficiency/scalability limitations
   mentioned above is considered as out-of-scope.

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2.3.  Some Other Considerations

   Note: review in future versions of this document whether the
   component list should be under the network-hardware-inventory instead
   of the network-element container.

   Note that in [RFC8345], topology and inventory are two subsets of
   network information.  However, considering the complexity of the
   existing topology models and having a better extension capability, we
   define a separate root for the inventory model.  We will consider
   some other ways to do some associations between the topology model
   and inventory model in the future.

   Note: review in future versions of this document whether network
   hardware inventory should be defined as an augmentation of the
   network model defined in [RFC8345] instead of under a new network-
   hardware-inventory root.

   The proposed YANG data model has been analysed so far to cover the
   requirements and use cases for Optical Network Hardware Inventory.

   Further analysis of requirements and use cases is needed to extend
   the applicability of this YANG data model to other types of networks
   (IP and microwave) and to identify which aspects are generic and
   which aspects are technology-specific for optical.

3.  Tree Diagrams

3.1.  Network Hardware Inventory Tree Diagram

   Figure 4 below shows the tree diagram of the YANG data model defined
   in module "ietf-network-hardware-inventory" (Section 4.1).

   module: ietf-network-hardware-inventory
     +--ro network-hardware-inventory
        +--ro equipment-rooms
        |  +--ro equipment-room* [uuid]
        |     +--ro uuid           yang:uuid
        |     +--ro name?          string
        |     +--ro description?   string
        |     +--ro alias?         string
        |     +--ro location?      string
        |     +--ro racks
        |        +--ro rack* [uuid]
        |           +--ro uuid                 yang:uuid
        |           +--ro name?                string
        |           +--ro description?         string
        |           +--ro alias?               string

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        |           +--ro rack-location
        |           |  +--ro equipment-room-name?   leafref
        |           |  +--ro row-number?            uint32
        |           |  +--ro column-number?         uint32
        |           +--ro height?              uint16
        |           +--ro width?               uint16
        |           +--ro depth?               uint16
        |           +--ro max-voltage?         uint16
        |           +--ro contained-chassis* [ne-ref component-ref]
        |              +--ro ne-ref               leafref
        |              +--ro component-ref        leafref
        |              +--ro relative-position?   uint8
        +--ro network-elements
           +--ro network-element* [uuid]
              +--ro uuid             yang:uuid
              +--ro name?            string
              +--ro description?     string
              +--ro alias?           string
              +--ro ne-location
              |  +--ro equipment-room-name*   leafref
              +--ro hardware-rev?    string
              +--ro software-rev?    string
              +--ro mfg-name?        string
              +--ro mfg-date?        yang:date-and-time
              +--ro part-number?     string
              +--ro serial-number?   string
              +--ro product-name?    string
              +--ro components
                 +--ro component* [uuid]
                    +--ro uuid                           yang:uuid
                    +--ro name?                          string
                    +--ro description?                   string
                    +--ro alias?                         string
                    +--ro location?                      string
                    +--ro class?                         identityref
                    +--ro contained-child*               -> ../uuid
                    +--ro parent-rel-pos?                int32
                    +--ro parent-component-references
                    |  +--ro component-reference* [index]
                    |     +--ro index    uint8
                    |     +--ro class?   -> ../../../class
                    |     +--ro uuid?    -> ../../../uuid
                    +--ro hardware-rev?                  string
                    +--ro firmware-rev?                  string
                    +--ro software-rev?                  string
                    +--ro serial-num?                    string
                    +--ro mfg-name?                      string
                    +--ro part-number?                   string

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                    +--ro asset-id?                      string
                    +--ro is-fru?                        boolean
                    +--ro mfg-date?
                    |       yang:date-and-time
                    +--ro uri*                           inet:uri
                    +--ro (component-class)?
                       +--:(chassis)
                       |  +--ro chassis-specific-info
                       +--:(container)
                       |  +--ro slot-specific-info
                       +--:(module)
                       |  +--ro board-specific-info
                       +--:(port)
                          +--ro port-specific-info

             Figure 4: Network Hardware inventory tree diagram

3.2.  Relationship between Topology and Network Inventory Tree Diagram

   Figure 5 below shows the tree diagram of the YANG data model defined
   in module "ietf-hw-inventory-ref-topo" (Section 4.2).

   module: ietf-hw-inventory-ref-topo

     augment /nw:networks/nw:network/nw:node:
       +--ro inventory-id?   leafref
     augment /nw:networks/nw:network/nw:node/nt:termination-point:
       +--ro inventory-id?   leafref

       Figure 5: Relationship between Topology and Network Inventory
                                Tree Diagram

4.  YANG Data Models

4.1.  YANG Data Model for Network Hardware Inventory

   <CODE BEGINS> file "ietf-network-hardware-inventory@2023-03-07.yang"
   module ietf-network-hardware-inventory {
     yang-version 1.1;
     namespace
       "urn:ietf:params:xml:ns:yang:ietf-network-hardware-inventory";
     prefix nhi;

     import ietf-yang-types {
       prefix yang;
       reference
         "RFC6991: Common YANG Data Types.";
     }

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     import iana-hardware {
       prefix ianahw;
       reference
         "https://www.iana.org/assignments/yang-parameters";
     }

     import ietf-inet-types {
       prefix inet;
       reference
         "RFC6991: Common YANG Data Types.";
     }

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

        Editor:   Chaode Yu
                  <yuchaode@huawei.com>

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

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

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

        Editor:   Jean-Francois Bouquier
                  <jeff.bouquier@vodafone.com>

        Editor:   Fabio Peruzzini
                  <fabio.peruzzini@telecomitalia.it>";

     description
       "This module defines a model for retrieving network hardware
       inventory.

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

       Copyright (c) 2022 IETF Trust and the persons
       identified as authors of the code.  All rights reserved.

       Redistribution and use in source and binary forms, with or
       without modification, is permitted pursuant to, and subject

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       to the license terms contained in, the Revised BSD License
       set forth in Section 4.c of the IETF Trust's Legal Provisions
       Relating to IETF Documents
       (https://trustee.ietf.org/license-info).

       This version of this YANG module is part of RFC XXXX; see
       the RFC itself for full legal notices.

       The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL
       NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'NOT RECOMMENDED',
       'MAY', and 'OPTIONAL' in this document are to be interpreted as
       described in BCP 14 (RFC 2119) (RFC 8174) when, and only when,
       they appear in all capitals, as shown here.";

     // 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 2023-03-09 {
       description
         "Initial version";
       reference
         "RFC XXXX: A YANG Data Model for Network Hardware Inventory.";
         //RFC Editor: replace XXXX with actual RFC number, update date
         //information and remove this note
     }

     container network-hardware-inventory {
       config false;
       description
         "The top-level container for the network inventory
         information.";
       uses equipment-rooms-grouping;
       uses network-elements-grouping;
     }

     grouping common-entity-attributes {
       description
         "A set of attributes which are common to all the entities
         (e.g., component, equipment room) defined in this module.";
       leaf uuid {
         type yang:uuid;
         description
           "Uniquely identifies an entity (e.g., component).";
       }
       leaf name {
         type string;

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         description
           "A name for an entity (e.g., component), as specified by
           a network manager, that provides a non-volatile 'handle'
           for the entity and that can be modified anytime during the
           entity lifetime.

           If no configured value exists, the server MAY set the value
           of this node to a locally unique value in the operational
           state.";
       }
       leaf description {
         type string;
         description "a textual description of inventory object";
       }
       leaf alias {
         type string;
         description
         "a alias name of inventory objects. This alias name can be
         specified by network manager.";
       }
     }

     grouping network-elements-grouping {
       description
         "The attributes of the network elements.";
       container network-elements {
         description
           "The container for the list of network elements.";
         list network-element {
           key uuid;
           description
             "The list of network elements within the network.";
           uses common-entity-attributes;
           container ne-location {
             description
               "The location information of this network element.";
             leaf-list equipment-room-name {
               type leafref {
                 path "/nhi:network-hardware-inventory/" +
                      "nhi:equipment-rooms/nhi:equipment-room/nhi:name";
               }
               description
                 "Names of equipment rooms where the NE is located.
                 Please note that a NE could be located in several
                 equipment rooms.";
             }
           }
           uses ne-specific-info-grouping;

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           uses components-grouping;
         }
       }
     }

     grouping ne-specific-info-grouping {
       description
         "Attributes applicable to network elements.";
       leaf hardware-rev {
         type string;
         description
           "The vendor-specific hardware revision string for the NE.";
       }
       leaf software-rev {
         type string;
         description
           "The vendor-specific software revision string for the NE.";
       }
       leaf mfg-name {
         type string;
         description "The name of the manufacturer of this NE";
       }
       leaf mfg-date {
         type yang:date-and-time;
         description "The date of manufacturing of the NE.";
       }
       leaf part-number {
         type string;
         description
           "The vendor-specific model name identifier string associated
            with this NE.  The preferred value is the customer-visible
            part number, which may be printed on the NE itself.";
       }
       leaf serial-number {
         type string;
         description
           "The vendor-specific serial number string for the NE";
       }
       leaf product-name {
         type string;
         description
           "indicates the vendor-spefic device type infomation.";
       }
     }

     grouping equipment-rooms-grouping {
       description
         "The attributes of the equipment rooms.";

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       container equipment-rooms {
         description
           "The container for the list of equipment rooms.";
         list equipment-room {
           key uuid;
           description
             "The list of equipment rooms within the network.";
           uses common-entity-attributes;
           leaf location {
             type string;
             description
               "compared with the location information of the other
               inventory objects, a GIS address is preferred for
               equipment room";
           }
           container racks {
             description
               "Top level container for the list of racks.";
             list rack {
               key uuid;
               description
                 "The list of racks within an equipment room.";
               uses common-entity-attributes;
               uses rack-specific-info-grouping;
               list contained-chassis {
                 key "ne-ref component-ref";
                 description
                   "The list of chassis within a rack.";
                 leaf ne-ref {
                   type leafref {
                     path "/nhi:network-hardware-inventory"
                     + "/nhi:network-elements/nhi:network-element"
                     + "/nhi:uuid";
                   }
                   description
                     "The reference to the network element containing
                     the chassis component.";
                 }
                 leaf component-ref {
                   type leafref {
                     path "/nhi:network-hardware-inventory"
                     + "/nhi:network-elements/nhi:network-element"
                     + "[nhi:uuid=current()/../ne-ref]/nhi:components"
                     + "/nhi:component/nhi:uuid";
                   }
                   description
                     "The reference to the chassis component within
                     the network element and contained by the rack.";

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                 }
                 leaf relative-position {
                   type uint8;
                   description "A relative position of chassis within
                   the rack";
                 }
               }
             }
           }
         }
       }
     }

     grouping rack-specific-info-grouping {
       description
         "Attributes applicable to racks only.";
       container rack-location {
         description
           "The location information of the rack, which comprises the
           name of the equipment room, row number, and column number.";
         leaf equipment-room-name {
           type leafref {
             path "/nhi:network-hardware-inventory/nhi:equipment-rooms"
             + "/nhi:equipment-room/nhi:name";
           }
           description
           "Name of equipment room where this rack is located.";
         }
         leaf row-number {
           type uint32;
           description
             "Identifies the row within the equipment room where
             the rack is located.";
         }
         leaf column-number {
           type uint32;
           description
             "Identifies the physical location of the rack within
             the column.";
         }
       }
       leaf height {
         type uint16;
         units millimeter;
         description
           "Rack height.";
       }
       leaf width {

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         type uint16;
         units millimeter;
         description
           "Rack width.";
       }
       leaf depth {
         type uint16;
         units millimeter;
         description
           "Rack depth.";
       }
       leaf max-voltage {
         type uint16;
         units volt;
         description
           "The maximum voltage could be supported by the rack.";
       }
     }

     grouping components-grouping {
       description
         "The attributes of the hardware components.";
       container components {
         description
           "The container for the list of components.";
         list component {
           key uuid;
           description
             "The list of components within a network element.";
           uses common-entity-attributes;
           leaf location {
             type string;
             description
               "A relative location information of this component.
               In optical transport network, the location string is
               using the following pattern:
                 '/ne=<nw-ne-name>[/r=<r_index>][/sh=<sh_index>
                 [/s_sh=<s_sh_index> ...]][[/sl=<sl_index>
                 [/s_sl=<s_sl_index> ...]][/p=<p_index> …]]'
               ";
           }
           leaf class {
             type identityref {
               base ianahw:hardware-class;
             }
             description
               "An indication of the general hardware type of the
                component.";

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             reference
               "RFC 8348: A YANG Data Model for Hardware Management.";
           }
           leaf-list contained-child {
             type leafref {
               path "../nhi:uuid";
             }
             description
               "The list of the identifiers of the child components
               physically contained within this component.";
           }
           leaf parent-rel-pos {
             type int32 {
               range "0 .. 2147483647";
             }
             description
               "The relative position with respect to the parent
               component among all the sibling components.";
             reference
               "RFC 6933: Entity MIB (Version 4) -
                          entPhysicalParentRelPos";
           }

           container parent-component-references {
             description
                 "The top level container for the list of the
                 identifiers of the parents of this component in a
                 hierarchy.";
             list component-reference {
               key index;
               description
                 "The list of the identifiers of the parents of this
                 component in a hierarchy.

                 The index parameter defines the hierarchy: the topmost
                 parent has an index of 0.";
               leaf index {
                 type uint8;
                 description
                   "The index of the parent with respect to the
                   hierarchy.";
               }
               leaf class {
                 type leafref {
                   path "../../../nhi:class";
                 }
                 description
                   "Class of the hierarchial parent component.";

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               }
               leaf uuid {
                 type leafref {
                   path "../../../nhi:uuid";
                 }
                 description
                   "The identifier of the parent's component in the
                   hierarchy.";
               }
             }
           }

           leaf hardware-rev {
             type string;
             description
               "The vendor-specific hardware revision string for the
                component.  The preferred value is the hardware revision
                identifier actually printed on the component itself (if
                present).";
             reference
               "RFC 6933: Entity MIB (Version 4) -
                          entPhysicalHardwareRev";
           }
           leaf firmware-rev {
             type string;
             description
               "The vendor-specific firmware revision string for the
                component.";
             reference
               "RFC 6933: Entity MIB (Version 4) -
                          entPhysicalFirmwareRev";
           }
           leaf software-rev {
             type string;
             description
               "The vendor-specific software revision string for the
                component.";
             reference
               "RFC 6933: Entity MIB (Version 4) -
                          entPhysicalSoftwareRev";
           }
           leaf serial-num {
             type string;
             description
               "The vendor-specific serial number string for the
                component.  The preferred value is the serial number
                string actually printed on the component itself (if
                present).";

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             reference
               "RFC 6933: Entity MIB (Version 4) -
               entPhysicalSerialNum";
           }
           leaf mfg-name {
             type string;
             description
               "The name of the manufacturer of this physical component.
                The preferred value is the manufacturer name string
                actually printed on the component itself (if present).

                Note that comparisons between instances of the
                'model-name', 'firmware-rev', 'software-rev', and
                'serial-num' nodes are only meaningful amongst
                components with the same value of 'mfg-name'.

                If the manufacturer name string associated with the
                physical component is unknown to the server, then this
                node is not instantiated.";
             reference
               "RFC 6933: Entity MIB (Version 4) - entPhysicalMfgName";
           }
           leaf part-number {
             type string;
             description
               "The vendor-specific model name identifier string
                associated with this physical component.  The preferred
                value is the customer-visible part number, which may be
                printed on the component itself.

                If the model name string associated with the physical
                component is unknown to the server, then this node is
                not instantiated.";
             reference
               "RFC 6933: Entity MIB (Version 4) -
               entPhysicalModelName";
           }
           leaf asset-id {
             type string;
             description
               "This node is a user-assigned asset tracking identifier
                for the component.

                A server implementation MAY map this leaf to the
                entPhysicalAssetID MIB object.  Such an implementation
                needs to use some mechanism to handle the differences in
                size and characters allowed between this leaf and
                entPhysicalAssetID.  The definition of such a mechanism

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                is outside the scope of this document.";
             reference
               "RFC 6933: Entity MIB (Version 4) - entPhysicalAssetID";
           }
           leaf is-fru {
             type boolean;
             description
               "This node indicates whether or not this component is
                considered a 'field-replaceable unit' by the vendor.  If
                this node contains the value 'true', then this component
                identifies a field-replaceable unit.  For all components
                that are permanently contained within a
                field-replaceable unit, the value 'false' should be
                returned for this node.";
             reference
               "RFC 6933: Entity MIB (Version 4) - entPhysicalIsFRU";
           }
           leaf mfg-date {
             type yang:date-and-time;
             description
               "The date of manufacturing of the managed component.";
             reference
               "RFC 6933: Entity MIB (Version 4) - entPhysicalMfgDate";
           }
           leaf-list uri {
             type inet:uri;
             description
               "This node contains identification information about the
                component.";
             reference
               "RFC 6933: Entity MIB (Version 4) - entPhysicalUris";
           }
           uses component-specific-info-grouping;
         }
       }
     }

     grouping component-specific-info-grouping {
       description
         "In case if there are some missing attributes of component not
         defined by RFC8348. These attributes could be
         component-specific.
         Here we provide a extension structure for all the components
         we recognized. We will enrich these component specifc
         containers in the future.";
       choice component-class {
         description
           "This extension differs between different component

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           classes.";
         case chassis {
           when "./class = 'ianahw:chassis'";
           container chassis-specific-info {
             description
               "This container contains some attributes belong to
               chassis only.";
             uses chassis-specific-info-grouping;
           }
         }
         case container {
           when "./class = 'ianahw:container'";
           container slot-specific-info {
             description
               "This container contains some attributes belong to
               slot or sub-slot only.";
             uses slot-specific-info-grouping;
           }
         }
         case module {
           when "./nhi:class = 'ianahw:module'";
           container board-specific-info {
             description
               "This container contains some attributes belong to
               board only.";
             uses board-specific-info-grouping;
           }
         }
         case port {
           when "./nhi:class = 'ianahw:port'";
           container port-specific-info {
             description
               "This container contains some attributes belong to
               port only.";
             uses port-specific-info-grouping;
           }
         }
       //TO BE ADDED: transceiver
       }
     }

     grouping chassis-specific-info-grouping {
     //To be enriched in the future.
       description
         "Specific attributes applicable to chassis only.";
     }

     grouping slot-specific-info-grouping {

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     //To be enriched in the future.
       description
         "Specific attributes applicable to slots only.";
     }

     grouping board-specific-info-grouping {
     //To be enriched in the future.
       description
         "Specific attributes applicable to boards only.";
     }

     grouping port-specific-info-grouping {
     //To be enriched in the future.
       description
         "Specific attributes applicable to ports only.";
     }
   }
   <CODE ENDS>

              Figure 6: Network Hardware inventory YANG module

4.2.  YANG Data Model for Relationship between Topology and Network
      Inventory

   <CODE BEGINS> file "ietf-hw-inventory-ref-topo@2023-03-10.yang"
   module ietf-hw-inventory-ref-topo {
    yang-version 1.1;
    namespace "urn:ietf:params:xml:ns:yang:ietf-hw-inventory-ref-topo";
    prefix hirt;

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

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

     import ietf-network-hardware-inventory {
       prefix nhi;
       reference
         "RFC XXXX: A YANG Data Model for Network Hardware Inventory.";
         //RFC Editor: replace XXXX with actual RFC number, update date
         //information and remove this note

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     }

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

       Editor:   Chaode Yu
                 <yuchaode@huawei.com>

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

       Editor:   Jean-Francois Bouquier
                 <jeff.bouquier@vodafone.com>

       Editor:   Fabio Peruzzini
                 <fabio.peruzzini@telecomitalia.it>

       Editor:   Phil Bedard
                 <phbedard@cisco.com>";

    description
      "This module defines a model for navigation between hardware
      inventory data module and network topology module.

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

      Copyright (c) 2021 IETF Trust and the persons
      identified as authors of the code.  All rights reserved.

      Redistribution and use in source and binary forms, with or
      without modification, is permitted pursuant to, and subject
      to the license terms contained in, the Simplified BSD License
      set forth in Section 4.c of the IETF Trust's Legal Provisions
      Relating to IETF Documents
      (https://trustee.ietf.org/license-info).
      This version of this YANG module is part of RFC XXXX; see
      the RFC itself for full legal notices.

      The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL
      NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'NOT RECOMMENDED',
      'MAY', and 'OPTIONAL' in this document are to be interpreted as
      described in BCP 14 (RFC 2119) (RFC 8174) when, and only when,
      they appear in all capitals, as shown here.";

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    // 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 2023-03-10 {
       description
         "Initial revision.";
        reference
          "RFC XXXX: A YANG Data Model for Network Hardware Inventory.";
          //RFC Editor: replace XXXX with actual RFC number, update date
          //information and remove this note
     }

     augment "/nw:networks/nw:network/nw:node" {
       description
         "Information that allows the relationship between the node in
         the topology and the Network Element (NE) in the network
         hardware inventory model from which the node is abstracted";

       leaf inventory-id {
       type leafref {
         path "/nhi:network-hardware-inventory/nhi:network-elements"
         + "/nhi:network-element/nhi:uuid";
       }
       config false;
       description
         "The identifier of the Network Element (NE) from which this
         node is abstracted";
       }
     }

     augment "/nw:networks/nw:network/nw:node/nt:termination-point" {
       description
         "Information that allows the relationship between the Link
         Termination Point (LTP) and the port component in the network
         hardware inventory model from which this LTP is abstracted.";

       leaf inventory-id {
       type leafref {
         path "/nhi:network-hardware-inventory/nhi:network-elements"
         + "/nhi:network-element/nhi:components/nhi:component"
         + "/nhi:uuid";
       }
       config false;
       description
           "The identifier of the port component from which this Link
           Termination Point (LTP) is abstracted";

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       }
     }
   }
   <CODE ENDS>

       Figure 7: Relationship between Topology and Network Inventory
                                YANG module

5.  Manageability Considerations

   <Add any manageability considerations>

6.  Security Considerations

   <Add any security considerations>

7.  IANA Considerations

   <Add any IANA considerations>

8.  References

8.1.  Normative References

   [IANA_YANG]
              IANA, "YANG Parameters", n.d.,
              <https://www.iana.org/assignments/yang-parameters>.

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

   [RFC6241]  Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
              and A. Bierman, Ed., "Network Configuration Protocol
              (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
              <https://www.rfc-editor.org/info/rfc6241>.

   [RFC6933]  Bierman, A., Romascanu, D., Quittek, J., and M.
              Chandramouli, "Entity MIB (Version 4)", RFC 6933,
              DOI 10.17487/RFC6933, May 2013,
              <https://www.rfc-editor.org/info/rfc6933>.

   [RFC6991]  Schoenwaelder, J., Ed., "Common YANG Data Types",
              RFC 6991, DOI 10.17487/RFC6991, July 2013,
              <https://www.rfc-editor.org/info/rfc6991>.

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   [RFC7950]  Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
              RFC 7950, DOI 10.17487/RFC7950, August 2016,
              <https://www.rfc-editor.org/info/rfc7950>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [RFC8340]  Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
              BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
              <https://www.rfc-editor.org/info/rfc8340>.

   [RFC8342]  Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
              and R. Wilton, "Network Management Datastore Architecture
              (NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018,
              <https://www.rfc-editor.org/info/rfc8342>.

   [RFC8348]  Bierman, A., Bjorklund, M., Dong, J., and D. Romascanu, "A
              YANG Data Model for Hardware Management", RFC 8348,
              DOI 10.17487/RFC8348, March 2018,
              <https://www.rfc-editor.org/info/rfc8348>.

   [TMF_SD2-20]
              TM Forum, "SD2-20_Equipment Model", TMF MTOSI 4.0, Network
              Resource Fulfilment (NRF), SD2-20 , May 2008,
              <https://www.tmforum.org/resources/suite/mtosi-4-0/>.

8.2.  Informative References

   [I-D.ietf-teas-actn-poi-applicability]
              Peruzzini, F., Bouquier, J., Busi, I., King, D., and D.
              Ceccarelli, "Applicability of Abstraction and Control of
              Traffic Engineered Networks (ACTN) to Packet Optical
              Integration (POI)", Work in Progress, Internet-Draft,
              draft-ietf-teas-actn-poi-applicability-08, 11 January
              2023, <https://datatracker.ietf.org/doc/html/draft-ietf-
              teas-actn-poi-applicability-08>.

   [ONF_TR-547]
              Open Networking Foundation (ONF), "TAPI v2.1.3 Reference
              Implementation Agreement", ONF TR-547 TAPI RIA v1.0 , July
              2020, <https://opennetworking.org/wp-
              content/uploads/2020/08/TR-547-TAPI-v2.1.3-Reference-
              Implementation-Agreement-1.pdf>.

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

Appendix A.  Appendix

A.1.  Comparison With Openconfig-platform Data Model

   Since more and more devices can be managed by domain controller
   through OpenConfig, to ensure that our inventory data model can cover
   these devices' inventory data, we have compared our inventory data
   model with the "openconfig-platform" model which is the data model
   used to manage inventory information in OpenConfig.

   Openconfig-platform data model is NE-level and uses a generic
   component concept to describe its inner devices and containers, which
   is similar to "ietf-hardware" model in [RFC8348].  Since we have also
   reused the component concept of [RFC8348] in our inventory data
   model, we can compare the component's attributes between "openconfig-
   platform" and our model directly , which is stated below:

   +========================+=======================+=================+
   | Attributes in oc-      | Attributes in our     | remark          |
   | platform               | model                 |                 |
   +========================+=======================+=================+
   | name                   | name                  |                 |
   +------------------------+-----------------------+-----------------+
   | type                   | class                 |                 |
   +------------------------+-----------------------+-----------------+
   | id                     | uuid                  |                 |
   +------------------------+-----------------------+-----------------+
   | location               | location              |                 |
   +------------------------+-----------------------+-----------------+
   | description            | description           |                 |
   +------------------------+-----------------------+-----------------+
   | mfg-name               | mfg-name              |                 |
   +------------------------+-----------------------+-----------------+
   | mfg-date               | mfg-date              |                 |
   +------------------------+-----------------------+-----------------+
   | hardware-version       | hardware-rev          |                 |
   +------------------------+-----------------------+-----------------+
   | firmware-version       | firmware-rev          |                 |
   +------------------------+-----------------------+-----------------+
   | software-version       | software-rev          |                 |
   +------------------------+-----------------------+-----------------+
   | serial-no              | serial-num            |                 |
   +------------------------+-----------------------+-----------------+

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   | part-no                | part-number           |                 |
   +------------------------+-----------------------+-----------------+
   | clei-code              |                       | TBD             |
   +------------------------+-----------------------+-----------------+
   | removable              | is-fru                |                 |
   +------------------------+-----------------------+-----------------+
   | oper-status            |                       | state data      |
   +------------------------+-----------------------+-----------------+
   | empty                  | contained-child?      | If there is no  |
   |                        |                       | contained       |
   |                        |                       | child, it is    |
   |                        |                       | empty.          |
   +------------------------+-----------------------+-----------------+
   | parent                 | parent-references     |                 |
   +------------------------+-----------------------+-----------------+
   | redundant-role         |                       | TBD             |
   +------------------------+-----------------------+-----------------+
   | last-switchover-reason |                       | state data      |
   +------------------------+-----------------------+-----------------+
   | last-switchover-time   |                       | state data      |
   +------------------------+-----------------------+-----------------+
   | last-reboot-reason     |                       | state data      |
   +------------------------+-----------------------+-----------------+
   | last-reboot-time       |                       | state data      |
   +------------------------+-----------------------+-----------------+
   | switchover-ready       |                       | state data      |
   +------------------------+-----------------------+-----------------+
   | temperature            |                       | performance     |
   |                        |                       | data            |
   +------------------------+-----------------------+-----------------+
   | memory                 |                       | performance     |
   |                        |                       | data            |
   +------------------------+-----------------------+-----------------+
   | allocated-power        |                       | TBD             |
   +------------------------+-----------------------+-----------------+
   | used-power             |                       | TBD             |
   +------------------------+-----------------------+-----------------+
   | pcie                   |                       | alarm data      |
   +------------------------+-----------------------+-----------------+
   | properties             |                       | TBD             |
   +------------------------+-----------------------+-----------------+
   | subcomponents          | contained-child       |                 |
   +------------------------+-----------------------+-----------------+
   | chassis                | chassis-specific-info |                 |
   +------------------------+-----------------------+-----------------+
   | port                   | port-specific-info    |                 |
   +------------------------+-----------------------+-----------------+
   | power-supply           |                       | TBD             |

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   +------------------------+-----------------------+-----------------+
   | fan                    |                       | Fan is          |
   |                        |                       | considered as a |
   |                        |                       | specific board. |
   |                        |                       | And no need to  |
   |                        |                       | define as a     |
   |                        |                       | single          |
   |                        |                       | component       |
   +------------------------+-----------------------+-----------------+
   | fabric                 |                       | TBD             |
   +------------------------+-----------------------+-----------------+
   | storage                |                       | For Optical and |
   |                        |                       | IP technology,  |
   |                        |                       | no need to      |
   |                        |                       | manage storage  |
   |                        |                       | on network      |
   |                        |                       | element         |
   +------------------------+-----------------------+-----------------+
   | cpu                    |                       | For Optical and |
   |                        |                       | IP technology,  |
   |                        |                       | no need to      |
   |                        |                       | manage CPU on   |
   |                        |                       | network element |
   +------------------------+-----------------------+-----------------+
   | integrated-circuit     | board-specific-info   |                 |
   +------------------------+-----------------------+-----------------+
   | backplane              |                       | Backplane is    |
   |                        |                       | considered as a |
   |                        |                       | part of board.  |
   |                        |                       | And no need to  |
   |                        |                       | define as a     |
   |                        |                       | single          |
   |                        |                       | component       |
   +------------------------+-----------------------+-----------------+
   | software-module        |                       | TBD             |
   +------------------------+-----------------------+-----------------+
   | controller-card        |                       | Controller card |
   |                        |                       | is considered   |
   |                        |                       | as a specific   |
   |                        |                       | functional      |
   |                        |                       | board.  And no  |
   |                        |                       | need to define  |
   |                        |                       | as a single     |
   |                        |                       | component       |
   +------------------------+-----------------------+-----------------+

      Table 2: Comparison between openconfig platform and inventory
                               data models

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   As it mentioned in Section 2.1.2 that state data and performance data
   are out of scope of our data model, it is same for alarm data and it
   should be defined in some other alarm data models separately.  And
   for some component specific structures in "openconfig-platform", we
   consider some of them can be contained by our existing structure,
   such as fan, backplane, and controller-card, while some others do not
   need to be included in this network inventory model like storage and
   cpu.

   Mostly, our inventory data model can cover the attributes from
   OpenConfig.

Acknowledgments

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

   This document was prepared using kramdown.

Contributors

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

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

   Victor Lopez
   Nokia
   Email: victor.lopez@nokia.com

   Bo Wu
   Huawei Technologies
   Email: lana.wubo@huawei.com

   Chenfang Zhang
   China Unicom
   Email: zhangcf80@chinaunicom.cn

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   Oscar Gonzalez de Dios
   Telefonica
   Email: oscar.gonzalezdedios@telefonica.com

Authors' Addresses

   Chaode Yu
   Huawei Technologies
   Email: yuchaode@huawei.com

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

   Jean-Francois Bouquier
   Vodafone
   Email: jeff.bouquier@vodafone.com

   Fabio Peruzzini
   TIM
   Email: fabio.peruzzini@telecomitalia.it

   Phil Bedard
   Cisco
   Email: phbedard@cisco.com

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