Internet-Draft Network Inventory Topology August 2024
Wu, et al. Expires 8 February 2025 [Page]
Workgroup:
IVY
Internet-Draft:
draft-ietf-ivy-network-inventory-topology-00
Published:
Intended Status:
Standards Track
Expires:
Authors:
B. Wu
Huawei
C. Zhou
China Mobile
Q. Wu
Huawei
M. Boucadair
Orange

A Network Inventory Topology Model

Abstract

This document defines a YANG model for network inventory topology to correlate the network inventory data with the general topology model to form a base underlay network, which can facilitate the mapping and correlation of the layer (e.g. Layer 2, Layer3) topology information above to the inventory data of the underlay network for agile service provisioning and network maintenance analysis.

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 8 February 2025.

Table of Contents

1. Introduction

[I-D.ietf-ivy-network-inventory-yang] defines base Network Inventory (NI) model to aggregate the inventory data of the Network Elements (NEs) on the network, which includes NEs and their hardware components, firmware components, and software components. Examples of inventory hardware components could be rack, shelf, slot, board and physical port. Examples of inventory software components could be platform operating system (OS), software-patch, bios, and boot-loader.

This document extends the RFC 8345 network topology model for network inventory mapping, which facilitates the correlation with existing network and topology models, such as SAP [RFC9408], L2 topology [RFC8944], and L3 topology [RFC8346], to support agile service provisioning and network maintenance.

In addition, the network inventory topology can also provide anchor points to mount specific device configuration and state information, e.g. QoS policies, ACL policies, to support configuration verification of cross-domain policies.

2. Requirements Language

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.

3. Sample Use Cases

3.1. Determin Available Resource of Service Attachment Points (SAPs)

The inventory topology model can be used as a base to correlate underlay information, such as physical port components. The figure belows gives an example of the usage.

During service provisioning, to check available physical port resources, the Service Attachment Points (SAPs) information can be associated with the underlay inventory information and interface information associated with the inventory topology, e.g. "parent-termination-point" of SAP Model can be associated with the "port-component-ref" and "interface-name" of the inventory topology model, which can be used to check the availability and capacity of physical ports.

                     +-----------------+
                     |     Customer    |
                     +--------+--------+
     Customer Service Models  |
        (e.g., L3SM, L2SM)    |
                     +--------+--------+
                     |    Service      |
                     |  Orchestration  |
                     +------+---+------+
                            |   |
          SAP Network Model |   | Inventory Topology Model
                     +------+---+------+
                     |     Network     |
                     |   Controller    |
                     +--------+--------+
                              |
        +---------------------+---------------------+
        |                  Network                  |
        +-------------------------------------------+

Figure 1: An Example Usage of Network Inventory Topology

3.2. The Example Digital Twin Network

[I-D.irtf-nmrg-network-digital-twin-arch] defines "digital twin network" as a virtual representation of the physical network. Such virtual representation of the network is meant to be used to analyze, diagnose, emulate, and then manage the physical network based on data, models, and interfaces.

The management system can use digital twin technology to build visual multi-layer topology maps for networks and endpoints with relationship types and dependencies, and identify potential impacts on configuration management information from incidents, problems, and changes.

The inventory topology model can, for example, be used to emulate several what-if scenario such as the impact of EOL or depletion of a hardware component on the network resilience and service availability.

4. Model Overview

The following tree diagram [RFC8340] provides an overview of the data model for "ietf-network-inventory-topology" module.

module: ietf-network-inventory-topology
  augment /nw:networks/nw:network/nw:network-types:
    +--rw network-inventory-mapping!
  augment /nw:networks/nw:network/nw:node:
    +--rw inventory-mapping-attributes
       +--rw node-name?            string
       +--ro ne-ref?               ne-ref
       +--rw system-mount-point
  augment /nw:networks/nw:network/nt:link:
    +--rw inventory-mapping-attributes
       +--rw link-name?    string
       +--ro cable-name?   string
       +--ro link-type?    string
  augment /nw:networks/nw:network/nw:node/nt:termination-point:
    +--rw inventory-mapping-attributes
       +--ro tp-name?              string
       +--ro port-component-ref?   leafref
       +--rw interface-name*       string
       +--rw system-mount-point
Figure 2: The Structure of the Network Inventory Mapping Data Model

The module augments the original "ietf-network- topology" modules as follows:

Being an independent underlaying topology, the inventory topology model associates inventory data with abstract topologies. It can be used as the "supporting-networks" of SAP, Layer 2, or Layer 3 topologies.

5. YANG Data model for Network Inventory Topology

The "ietf-network-inventory-topology" module uses types defined in [RFC8345].

<CODE BEGINS> file="ietf-network-inventory-topology@2024-04-29.yang"
module ietf-network-inventory-topology {
  yang-version 1.1;
  namespace
    "urn:ietf:params:xml:ns:yang:ietf-network-inventory-topology";
  prefix nwit;

  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";
  }
  import ietf-network-inventory {
    prefix nwi;
    reference
      "RFC AAAA: A YANG Data Model for Network Inventory";
  }

  organization
    "IETF Network Inventory YANG (ivy) Working Group";
  contact
    "WG Web:   <https://datatracker.ietf.org/wg/ivy>
     WG List:  <mailto:inventory-yang@ietf.org>

     Editor: Bo Wu
          <lana.wubo@huawei.com>
     Editor: Cheng Zhou
          <zhouchengyjy@chinamobile.com>
     Editor: Qin Wu
          <bill.wu@huawei.com>
     Editor: Mohamed Boucadair
          <mohamed.boucadair@orange.com>";
  description
    "This YANG module defines XXX.

     Copyright (c) 2024 IETF Trust and the persons identified
     as authors of the code. All rights reserved.

     Redistribution and use in source and binary forms, with
     or without modification, is permitted pursuant to, and
     subject to the license terms contained in, the Revised
     BSD License set forth in Section 4.c of the IETF Trust's
     Legal Provisions Relating to IETF Documents
     (https://trustee.ietf.org/license-info).

     This version of this YANG module is part of RFC XXXX
     (https://www.rfc-editor.org/info/rfcXXXX); see the RFC
     itself for full legal notices.";

  revision 2024-04-29 {
    description
      "Initial revision.";
    reference
      "RFC XXXX: A YANG Data Model for Network Inventory Mapping
                     Topology";
  }

  /* Identities */
  /* Typedef */

  typedef ne-ref {
    type leafref {
      path "/nwi:network-inventory/nwi:network-elements"
         + "/nwi:network-element/nwi:ne-id";
    }
    description
      "This type is used by data models that need to reference
       Network Element.";
  }

  /* Groupings */

  grouping inventory-mapping-network-type {
    description
      "Indicates the topology type to be Network Inventory mapping.";
    container network-inventory-mapping {
      presence "Indicates Network Inventory mapping topology.";
      description
        "The presence of the container node indicates
         Network Inventory mapping.";
    }
  }

  grouping system-mount-point {
    description
      "Indicates system configuration or state mount point.";
    container system-mount-point {
      description
        "Container for system configuration or state mount point.";
    }
  }

  grouping node-inventory-attributes {
    description
      "Network Inventory mapping node scope attributes";
    container inventory-mapping-attributes {
      description
        "The container node attributes of Network Inventory mapping.";
      leaf node-name {
        type string;
        description
          "The name of the node.";
      }
      leaf ne-ref {
        type ne-ref;
        config false;
        description
          "The reference of the Network Element (NE) from which this
           node is abstracted.";
      }
      uses system-mount-point;
    }
  }

  grouping termination-point-inventory-attributes {
    description
      "Network Inventory mapping termination point (TP) scope
       attributes";
    container inventory-mapping-attributes {
      description
        "The container TP attributes of Network Inventory mapping.";
      leaf tp-name {
        type string;
        config false;
        description
          "The name of the TP.";
      }
      leaf port-component-ref {
        type leafref {
          path
            "/nwi:network-inventory/nwi:network-elements"
          + "/nwi:network-element[nwi:ne-id=current()/../../../"
          + "inventory-mapping-attributes/ne-ref]/nwi:components"
          + "/nwi:component/nwi:component-id";
        }
        config false;
        description
          "The reference of the port component from which this
           termination point is abstracted.";
      }
      leaf-list interface-name {
        type string;
        description
          "Name of the interface.  The name can (but does not
           have to) correspond to an interface reference of a
           containing node's interface, i.e., the path name of a
           corresponding interface data node on the containing
           node is reminiscent of data type interface-ref defined
           in RFC 8343.  It should be noted that data type
           interface-ref of RFC 8343 cannot be used directly,
           as this data type is used to reference an interface
           in a datastore of a single node in the network, not
           to uniquely reference interfaces across a network.";
      }
      uses system-mount-point;
    }
  }

  grouping link-inventory-attributes {
    description
      "Network Inventory mapping link scope attributes";
    container inventory-mapping-attributes {
      description
        "The container link attributes of network inventory mapping.";
      leaf link-name {
        type string;
        description
          "The name of the link.";
      }
      leaf cable-name {
        type string;
        config false;
        description
          "The reference of the cable inventory from which
           this link is abstracted
           Note: this will be changed based on the future inventoy
           cable model.";
      }
      leaf link-type {
        type string;
        config false;
        description
          "The type of the link.
           Note: this will be changed based on the future inventoy
           cable model.";
      }
    }
  }

  /* Main blocks */

  augment "/nw:networks/nw:network/nw:network-types" {
    description
      "Introduces new network type for network inventory mapping.";
    uses inventory-mapping-network-type;
  }

  augment "/nw:networks/nw:network/nw:node" {
    when '/nw:networks/nw:network/nw:network-types/
   nwit:network-inventory-mapping' {
      description
        "Augmentation parameters apply only for network inventory
         mapping.";
    }
    description
      "Configuration parameters for inventory at the node
       level.";
    uses node-inventory-attributes;
  }

  augment "/nw:networks/nw:network/nt:link" {
    when '/nw:networks/nw:network/nw:network-types/
     nwit:network-inventory-mapping' {
      description
        "Augmentation parameters apply only for network
         inventory.";
    }
    description
      "Augments inventory topology link information.";
    uses link-inventory-attributes;
  }

  augment
    "/nw:networks/nw:network/nw:node/nt:termination-point" {
      when '/nw:networks/nw:network/nw:network-types/
     nwit:network-inventory-mapping' {
        description
          "Augmentation parameters apply only for network
           inventory.";
      }
      description
        "Augments inventory termination point information.";
      uses termination-point-inventory-attributes;
  }
}


<CODE ENDS>

6. Security Considerations

The YANG module specified in this document defines a data schema designed to be accessed through network management protocols such as NETCONF [RFC6241] or RESTCONF [RFC8040]. The lowest NETCONF layer is the secure transport layer, and the required secure transport is Secure Shell (SSH) [RFC6242]. The lowest RESTCONF layer is HTTPS, and the required secure transport is TLS [RFC8446].

The Network Configuration Access Control Model (NACM) [RFC8341] provides a means of restricting access to specific NETCONF or RESTCONF users to a preconfigured subset of all available NETCONF or RESTCONF protocol operations and contents. Thus, NACM SHOULD be used to restrict the NSF registration from unauthorized users.

There are a number of data nodes defined in this YANG module that are writable, creatable, and deletable (i.e., config true, which is the default). These data nodes may be considered sensitive or vulnerable in some network environments. Write operations to these data nodes could have a negative effect on network and security operations.

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:

<<<to be completed>>>

7. Privacy Considerations

The model includes sensitive PII data. More to be discussed:

8. IANA Considerations

This document registers a URI in the "IETF XML Registry" [RFC3688]. Following the format in [RFC3688], the following registration has been made.

     URI: urn:ietf:params:xml:ns:yang:ietf-network-inventory-topology
     Registrant Contact: The IESG.
     XML: N/A, the requested URI is an XML namespace.

This document registers a YANG module in the "YANG Module Names" registry[RFC7950] .

     name:         ietf-network-inventory-topology
     namespace:    urn:ietf:params:xml:ns:yang:ietf-network-inventory-topology
     prefix:       nwit
     maintained by IANA:
     reference:    RFC xxxx

9. Acknowledgements

The authors wish to thank Italo Busi, Olga Havel, Aihua Guo, Oscar Gonzalez de Dios, and many others for their helpful comments and suggestions.

10. Contributors

The following authors contributed significantly to this document:

   Chaode Yu
   Huawei Technologies
   Email: yuchaode@huawei.com

11. References

11.1. Normative References

[I-D.ietf-ivy-network-inventory-yang]
Yu, C., Belotti, S., Bouquier, J., Peruzzini, F., and P. Bedard, "A YANG Data Model for Network Inventory", Work in Progress, Internet-Draft, draft-ietf-ivy-network-inventory-yang-03, , <https://datatracker.ietf.org/doc/html/draft-ietf-ivy-network-inventory-yang-03>.
[RFC2119]
Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, , <https://www.rfc-editor.org/info/rfc2119>.
[RFC3688]
Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, , <https://www.rfc-editor.org/info/rfc3688>.
[RFC6241]
Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., and A. Bierman, Ed., "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, , <https://www.rfc-editor.org/info/rfc6241>.
[RFC6242]
Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, , <https://www.rfc-editor.org/info/rfc6242>.
[RFC7950]
Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, , <https://www.rfc-editor.org/info/rfc7950>.
[RFC8040]
Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, , <https://www.rfc-editor.org/info/rfc8040>.
[RFC8174]
Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, , <https://www.rfc-editor.org/info/rfc8174>.
[RFC8341]
Bierman, A. and M. Bjorklund, "Network Configuration Access Control Model", STD 91, RFC 8341, DOI 10.17487/RFC8341, , <https://www.rfc-editor.org/info/rfc8341>.
[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, , <https://www.rfc-editor.org/info/rfc8345>.
[RFC8446]
Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10.17487/RFC8446, , <https://www.rfc-editor.org/info/rfc8446>.

11.2. Informative References

[I-D.irtf-nmrg-network-digital-twin-arch]
Zhou, C., Yang, H., Duan, X., Lopez, D., Pastor, A., Wu, Q., Boucadair, M., and C. Jacquenet, "Network Digital Twin: Concepts and Reference Architecture", Work in Progress, Internet-Draft, draft-irtf-nmrg-network-digital-twin-arch-06, , <https://datatracker.ietf.org/doc/html/draft-irtf-nmrg-network-digital-twin-arch-06>.
[RFC8340]
Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, , <https://www.rfc-editor.org/info/rfc8340>.
[RFC8346]
Clemm, A., Medved, J., Varga, R., Liu, X., Ananthakrishnan, H., and N. Bahadur, "A YANG Data Model for Layer 3 Topologies", RFC 8346, DOI 10.17487/RFC8346, , <https://www.rfc-editor.org/info/rfc8346>.
[RFC8944]
Dong, J., Wei, X., Wu, Q., Boucadair, M., and A. Liu, "A YANG Data Model for Layer 2 Network Topologies", RFC 8944, DOI 10.17487/RFC8944, , <https://www.rfc-editor.org/info/rfc8944>.
[RFC9408]
Boucadair, M., Ed., Gonzalez de Dios, O., Barguil, S., Wu, Q., and V. Lopez, "A YANG Network Data Model for Service Attachment Points (SAPs)", RFC 9408, DOI 10.17487/RFC9408, , <https://www.rfc-editor.org/info/rfc9408>.

Appendix A. Option to correlate between Topologies and Network Inventory

The "ietf-network-inventory-topology" provides the topology mapping with the network inventory by using references. This design does not impact the existing topology models.

This appendix also introduces a YANG module that defines a simple topology model for network inventory reference. This module is intended to serve as an example that illustrates how the general topology model can be refined with inventory references across multiple levels of topology, e.g. TE topology, Layer 2 topology, Layer 3 topology, service attachment points (SAPs) topology.

A.1. Model Overview

Figure 3 below shows the tree diagram of the YANG data model defined in module "example-topo-inventory-ref"

module: example-topology-inv-ref
  augment /nw:networks/nw:network/nw:node:
    +--ro ne-reference?   ne-ref
  augment /nw:networks/nw:network/nw:node/nt:termination-point:
    +--ro port-component-ref?   leafref
Figure 3: Topology with Network Inventory Reference Tree

A.2. Network Inventory Reference YANG Module

The Topology Inventory Reference YANG module is specified below. As mentioned, the module is intended as an example for how the topology model can be extended to cover inventory references, but it is only for discusson. Accordingly, the module is not delimited with <CODE BEGINS> and <CODE ENDS> tags.

module example-topology-inv-ref {
  yang-version 1.1;
  namespace "urn:ietf:params:xml:ns:yang:example-topology-inv-ref";
  prefix nwir;

  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";
  }

  import ietf-network-inventory {
    prefix nwi;
    reference
      "RFC AAAA: A YANG Data Model for Network Inventory";
  }


  description
    "This module is intended as an example for how the
          base topology model can be extended to cover
          inventory references.";

  /* Main blocks */

  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
       inventory model from which the node is abstracted";
    leaf ne-ref {
      type leafref {
        path "/nwi:network-inventory/nwi:network-elements"
           + "/nwi:network-element/nwi:ne-id";
      }
      config false;
      description
        "The reference 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
         Termination Point (TP) and the port component in the network
         inventory model from which this TP is abstracted.";
      leaf port-component-ref {
        type leafref {
          path "/nwi:network-inventory/nwi:network-elements"
             + "/nwi:network-element[nwi:ne-id=current()/../../"
             + "ne-ref]/nwi:components/nwi:component"
             + "/nwi:component-id";
        }
        config false;
        description
          "The reference of the port component from which this
           Termination Point (TP) is abstracted";
      }
  }
}

Appendix B. Network Policy Management in Enterprise Network

Enterprise networks are becoming heterogenous and supporting a variety of device types, such as BYOD vs. enterprise-supplied devices, Internet of things (IoT) devices, IP phones, printers, IP cameras), OT (Operation Technology) devices (e.g., sensors), etc. Also, these networks are designed to support both localized applications and cloud-based applications (e.g., public cloud computing, storage, etc.), or hybrid applications. Also, means to access network resources are not anymore from within specific sites, but access can be granted from anywhere. Dedicated gateways and authorization procedures are being generalized.

This trend is observed for the medical, power, manufacturing, or other infrastructure industries. These networks host a large number of multi-vendor IoT or OT devices, with frequent additions and changes. These complex environments often expose unknown safety and reliability blind spots.

The endpoints connected to an Enterprise network lack unified modelling and lifecycle management, and different services are modelled, collected, processed, and stored separately. The same category of network device and network endpoints may be (repeatedly) discovered, processed, and stored. Therefore, the inventory is difficult to manage when they are tracked in different places. Maintaining a centralized and up-to-date inventory is a technical enabler in order to implement a coherent control strategy for all endpoint types connected to an Enterprise network.

Figure 4 shows an example of an enterprise network consisting of two network domains: one campus network domain and one cloud network domain. The inventory data in the network can include network infrastructure devices (such as routers, switchs, security devices) and network endpoints (such as IoT/OT devices, servers, laptop, mobile devices). The management systems or network controllers in different domains can automatically collect or discover the inventory by multiple approaches.

            +-------------------------------------+
            | Service/network   Orchestration     |
            +-------------------------------------+
                |                               |
                | Network Inventory Model       |
                | Network Inventory Topology Model
                |                               |
        +----------------+              +----------------+
        | Campus manager |              | SD-WAN manager |
        +----------------+              +-------+--------+
                |                               |
                |                               |
                |                               |
  +-------------------------+            +------+--------------------+
  |     Campus Domain #1    |            |     Cloud network         |
  |                         |            |                           |
  |-------+  +-----------+  |            | +-----------+   +-------+ |
  |+IT/OTs+- +  Router   +--+---------   +-+vRouter    +---+Service| |
  |-------+  +-----------+  |            | ------------+   +-------+ |
  |                         |            |                           |
  |Site A                   |            |             Cloud Site B  |
  +-------------------------+            +---------------------------+
Figure 4: An Example of Enterprise Network Inventory Management

With the inventory data collected from the underlying network, the network orchestration system can centrally manage security and network policies related to network endpoints.

Authors' Addresses

Bo Wu
Huawei
101 Software Avenue, Yuhua District
Nanjing
Jiangsu, 210012
China
Cheng Zhou
China Mobile
Beijing
100053
China
Qin Wu
Huawei
101 Software Avenue, Yuhua District
Nanjing
Jiangsu, 210012
China
Mohamed Boucadair
Orange
Rennes 35000
France