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Data Model for Computing-Aware Traffic Steering (CATS)
draft-yl-cats-data-model-05

Document Type Active Internet-Draft (individual)
Authors Huijuan Yao , Changwang Lin , Zhenqiang Li , Quan Xiong , Luis M. Contreras
Last updated 2025-12-01
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draft-yl-cats-data-model-05
CATS Working Group                                               H. Yao
Internet Draft                                             China Mobile
Intended status: Standards Track                                 C. Lin
Expires: March 10, 2026                            New H3C Technologies
                                                                  Z. Li
                                                           China Mobile
                                                               Q. Xiong
                                                        ZTE Corporation
                                                        L. M. Contreras
                                                             Telefonica
                                                       December 1, 2025

           Data Model for Computing-Aware Traffic Steering (CATS)
                        draft-yl-cats-data-model-05

Abstract

   This document defines a YANG data model for the configuration and
   management of Computing-Aware Traffic Steering (CATS) systems.

   The YANG module 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 May 10, 2026.

Copyright Notice

   Copyright (c) 2025 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

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   (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...................................................2
      1.1. Terminology...............................................3
      1.2. Conventions Used in This Document.........................3
      1.3. Tree Diagrams.............................................4
      1.4. Prefixes in Data Node Names...............................4
   2. CATS System Overview...........................................4
   3. Design of CATS Data Model......................................5
      3.1. Scope of Model............................................5
      3.2. Specification.............................................6
      3.3. Model Structure...........................................6
         3.3.1. CATS base............................................7
         3.3.2. CATS traffic-classifier..............................8
         3.3.3. CATS service-metric..................................9
         3.3.4. CATS notify..........................................9
   4. CATS YANG Module..............................................10
   5. Security Considerations.......................................16
   6. IANA Considerations...........................................18
   7. References....................................................18
      7.1. Normative References.....................................18
      7.2. Informative References...................................20
   Contributors.....................................................21
   Authors' Addresses...............................................21

1. Introduction

   [I-D.ietf-cats-framework] introduces a framework for Computing-Aware
   Traffic Steering (CATS). This document defines a YANG data model for
   configuring and managing the CATS system. The model extends the
   ietf-routing YANG model defined in [RFC8349], is agnostic to
   specific protocol extensions, and conforms to the framework
   definition to serve as a critical diagnostic or control mechanism.

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1.1. Terminology

   The following terms as defined in [I-D.draft-ietf- cats-framework]
   are used:

   CS-ID: CATS Service ID.

   CSCI-ID: CATS Service Contact Instance ID.

   C-SMA: CATS Service Metric Agent.

   C-NMA: CATS Network Metric Agent.

   C-PS: CATS Path Selector.

   C-TC: CATS Traffic Classifier.

   The new defined terms:

   C-CIB: CATS Computing Information Base, as shown in Figure 1,
      responsible for maintaining CATS network computing information.
      Provides basic data for the C-SMA.

   C-NIB: CATS Network Information Base, as shown in Figure 1,
      responsible for maintaining CATS network information. Provides
      basic data for the C-NMA.

   CATS-SBI: The CATS Southbound Interface, as shown in Figure 1. The
      interface between the CATS Forwarders and the CATS Control Plane
      (regardless of the protocols used in the Control Plane). It could
      be used to report computing metric information from CATS
      Forwarders to the Control Plane, and also could be used to send
      path and service policy information or service information from
      the Control Plane to CATS-Forwarders.

   C-SMA API: An extended interface between the Control Plane or
      Management Plane and the C-SMA, or between CATS-Forwarders and
      service-instances, as shown in Figure 1, it is used to report
      service metric information to the Control Plane or CATS-
      Forwarders.

1.2. Conventions Used in This Document

   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

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   BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

1.3. Tree Diagrams

   Tree diagrams used in this document follow the notation defined in
   [RFC8340].

1.4. Prefixes in Data Node Names

   In this document, names of data nodes, actions, and other data model
   objects are often used without a prefix, as long as it is clear from
   the context in which YANG module each name is defined. Otherwise,
   names are prefixed using the standard prefix associated with the
   corresponding YANG module, as shown in Table 1.

             +------------+-------------------------+-------------------+
             | Prefix     | YANG module             | Reference         |
             +------------+-------------------------+-------------------+
             | ip         | ietf-ip                 | [RFC8344]         |
             | rt         | ietf-routing            | [RFC8349]         |
             | cats       | ietf-cats               | Section 3         |
             | yang       | ietf-yang-types         | [RFC6991]         |
             | inet       | ietf-inet-types         | [RFC6991]         |
             +------------+-------------------------+-------------------+
                  Table 1: Prefixes and Corresponding YANG Modules

2. CATS System Overview

   As defined in [I-D.ietf-cats-framework], the CATS framework
   structure consists of the C-SMA (responsible for maintaining service
   metrics), the C-NMA (responsible for maintaining network metrics),
   the C-PS (responsible for maintaining forwarding table entries), and
   the C-TC (responsible for traffic classification), as shown in
   Figure 1.

   The C-CIB and C-NIB are defined in the management plane. The CATS-
   SBI is used to exchange information between CATS Forwarders and the
   Control Plane. The C-SMA API is an extended interface to report
   service metric information between the Control Plane and the C-SMA
   or between CATS-Forwarders and service-instance.

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                 +----------------------------------+               +----------+
                 | Management                       |   C-SMA API   |          |
                 | Plane   +------+----------+      |<==============|   C-SMA  |
                 |         |      |          |      |               |          |
                 |         |   +--v---+   +--v---+  |               +------+---+
                 |         |   |C-CIB |   |C-NIB |  |                      |
                 |         |   +---^--+   +--^---+  |                      |
                 |         |       |         |      |                      |
                 +---------|-------|---------|------+                      |
                 | Control |   +---v--+   +--v---+  |                      |
                 | Plane   |   |C-SMA |   |C-NMA |  |                      |
                 |         |   +------+   +------+  |                      |
                 |         |                        |                      |
                 |         |   +-------+            |                      |
                 |         +-->| C-PS  |            |                      |
                 |             +-------+            |                      |
                 +----------------------------------+                      |
                    /\ CATS-SBI  C-SMA API/\    /\ CATS-SBI                |
                    ||                    ||    ||                         |
                    \/                    ||    \/                         |
    +--------------------+    +--------------------------------+           |
    | CATS-     +------+ |    | CATS-     +-----+-------+      | C-SMA API +--------+
    | Forwarder1| C-TC | |    | Forwarder2|C-TC |  C-PS |      |<==========| +--------+
    |           +------+ |    |           +-----+---+---+      |           | |Service |
    |                    |    |                     |          |           | |Contact |
    +--------------------+    |                     |          |           +-|Instance|
                              |              +------+---+      |             +--------+
                              |              |          |      |                 |
                              |          +---+--+    +--+---+  |           +--------+
                              |          |C-SMA |    |C-NMA |  |           | +--------+
                              |          +------+    +------+  |           | |Service |
                              +--------------------------------+           +-|Instance|
                                                                             +--------+
                  Figure 1: CATS System Architecture

3. Design of CATS Data Model

3.1. Scope of Model

   The model covers CATS systems as described in [I-D.ietf-cats-
   framework]. This model can be used to configure and manage CATS
   systems.

   The operational state data and statistics can be retrieved by this
   model. The subscription and push mechanism defined in [RFC8639] and
   [RFC8641] can be implemented by the user to subscribe to
   notifications on the data nodes in this model.

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   The model contains all the basic configuration parameters to operate
   the CATS system. Depending on the implementation choices, some
   systems might not allow some of the advanced parameters to be
   configurable.

   Occasionally-implemented parameters are modeled as optional features
   in this model. This model can be extended, and it has been
   structured in a way that such extensions can be conveniently made.

3.2. Specification

   This model imports from and augments the ietf-routing YANG model
   defined in [RFC8349]. Both configuration branch and state branch of
   [RFC8349] are augmented. The configuration branch covers node base
   and policy configuration. The container "cats" is the top level
   container in this data model.

   The YANG data model defined in this document conforms to the Network
   Management Datastore Architecture (NMDA) [RFC8342]. The operational
   state data is combined with the associated configuration data in the
   same hierarchy [RFC8407].

3.3. Model Structure

   This document defines a YANG data model for the configuration and
   management of CATS corresponding data. The data model is applicable
   to the CATS-SBI interface and the C-SMA API interface in Figure 1.

   The CATS YANG model includes basic CATS objects, traffic-classifier
   objects, and service-metric objects. The model also includes YANG
   notifications.

   o The CATS base table provides interfaces for the functionality of
      the C-PS component, which can be used for communication between
      the Control Plane and the C-SMA, as well as for the interface
      between the Control Plane and the CATS-Forwarder.

   o The CATS traffic-classifier table provides interfaces for the
      functionality of the C-TC component, which can be used for
      communication between the Control Plane and the CATS-Forwarder.
      The Control Plane can distribute directly CATS traffic-classifier
      table to the CATS-Forwarder, allowing the CATS-Forwarder to
      proactively select paths according to forwarding policies.

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   o The CATS service-metric table provides interfaces for the C-SMA
      component, which can be used for communication between the
      Control Plane and the CATS-Forwarder, as well as for transmitting
      service metric information from the C-SMA to the Control Plane.
      It is also used for forwarding service metric information from
      the Control Plane to the CATS-Forwarder.

   o The CATS notify table is used by the management layer component
      and can be utilized for the CATS-Forwarder to report events to
      the Control Plane.

   The following is a tree representation of the CATS YANG model:

    module: ietf-cats
      augment /rt:routing:
        +--rw cats
        |  +--rw base
        |  |     ...
        |  |
        |  +--rw traffic-classifiers
        |  |     ...
        |  |
        |  +--rw service-metrics
        |  |     ...
        |  |
        |  +--n notify
        |  |    ...

               Figure 2: Yang Organization and Hierarchy

3.3.1. CATS base

        |  +--rw base
        |  |  +--rw enable          bool
        |  |  +--rw update-interval uint32
        |  |  +--rw metric-limits   uint32
        |  |  +--rw flow-limits     uint32
        |  |  +--rw flow-timeout    uint32
        |  |  +--rw service-policy
        |  |     +--rw cs-id        index, type cs-id
        |  |     +--rw policy-type  enumeration

                  Figure 3: Base configuration tree view

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   In the base, you can set the "enable" attribute to enable/disable
   CATS function on a per-device basis. When set to false, the CATS
   function component is shut down.

   You can set the "update-interval" parameter to determine the
   interval at which the C-SMA notifies the C-PS of metric changes. The
   default value for this interval is 30 seconds.

   You can set the maximum number of metric table entries by
   configuring "metric-limits".

   You can set the maximum number of flow tables by configuring "flow-
   limits".

   When flow tables have been inactive for a long period of time, it is
   necessary to age out the stale state entries. This can be achieved
   by configuring "flow-timeout" to control the aging time of flow
   tables.

   You can set the service-policy table for traffic steering, which
   includes affinity-based, service-metric-based, network-metric-based,
   and combined service-metric and network-metric-based steering.

3.3.2. CATS traffic-classifier

        |  +--rw traffic-classifiers
        |  |   +--rw traffic-classifier
        |  |      +--rw cs-id               index,type cs-id
        |  |      +--rw description         string
        |  |      +--rw server-port         uint16
        |  |      +--rw protocol            uint8

                  Figure 4: traffic-classifier tree view

   The CATS traffic-classifier table is used to define the features of
   the service and to classify the traffic.

   The "cs-id" is used to uniquely identify a CATS service, and the
   "description" serves to document its content.

   The "server-port" defines the application port for a CATS service.
   This port number matches the destination port in the IP packets of
   data flows destined for the service.

   The "protocol" defines the application transport protocol for a CATS
   service. This protocol number matches the protocol in the IP packets
   of data flows destined for the service.

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3.3.3. CATS service-metric

        |  +--rw service-metrics
        |  |   +--rw service-metric
        |  |      +--rw cs-id               index, type cs-id
        |  |      +--rw csci-id             index, type csci-id
        |  |      +--rw source-type         index, source-type
        |  |      +--rw priority            uint8
        |  |      +--rw affinity            uint8
        |  |      +--rw location            inet:ip-address
        |  |      +--rw metrics
        |  |         +--rw metric
        |  |            +--rw metric-type   index, type uint
        |  |            +--rw metric-value  uint32

                     Figure 5: Service-metric tree view

   The CATS service-metric table is used to control the delivery
   service metrics on the control plane, thereby generating the
   forwarding table on the forwarding plane in conjunction with network
   metrics.

   The "cs-id" is used to uniquely identify a CATS service, and the
   "csci-id" is used to represent an instance of that service. The
   "source-type" indicates the source protocol of this service metric
   information, such as a static protocol.

   The "priority" indicates the priority of different service instances
   of the same service, and the "affinity" indicates the affinity
   between this service and its service site.

   The "location" indicates the IP address of the service site where
   this service instance resides. And the "metrics" indicates different
   types of service metric values.

3.3.4. CATS notify

        |  +--n notify
        |  |     +--ro entry-limit-reached  boolean
        |  |     +--ro flow-limit-reached   boolean

                     Figure 6: Notify tree view

   When the number of CATS table entries reaches the maximum and when
   the number of entries goes from maximum to not being maximum, an
   event notification will be sent indicating the change.

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4. CATS YANG Module

   <CODE BEGINS> file "ietf-cats@2025-11-05.yang"

   module ietf-cats {
     yang-version 1.1;
     namespace "urn:ietf:params:xml:ns:yang:ietf-cats";
     prefix cats;

     import ietf-routing {
       prefix rt;
       reference
         "RFC 8349: A YANG Data Model for Routing
          Management (NMDA Version)";
     }

     import ietf-inet-types {
       prefix inet;
       reference
         "RFC 6991: Common YANG Data Types";
     }

     organization
       "IETF Computing-Aware Traffic Steering
        (CATS) Working Group";
     contact
       "WG Web:  <https://datatracker.ietf.org/group/cats/>
        WG List: <mailto:cats@ietf.org>
        Author:  Huijuan Yao
                 <mailto:yaohuijuan@chinamobile.com>
        Author:  Changwang Lin
                 <mailto:linchangwang.04414@h3c.com>
        Author:  Zhenqiang Li
                 <mailto:lizhenqiang@chinamobile.com>
        Author:  Quan Xiong
                 <mailto:xiong.quan@zte.com.cn>
        Author:  Luis M. Contreras
                 <mailto:luismiguel.contrerasmurillo@telefonica.com>
        ";

     description
       "This module describes a YANG model for CATS.
        This YANG model conforms to the Network Management
        Datastore Architecture (NMDA) as described in RFC 8342.

        Copyright (c) 2025 IETF Trust and the persons identified as
        authors of the code. All rights reserved.

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        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.

        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.";

     revision 2025-11-05 {
       description
         "Initial Version";
       reference
         "RFC XXXX: YANG Data Model for CATS";
      }

     typedef cs-id {
       type union {
         type uint32;
         type inet:ipv4-address;
         type inet:ipv6-address;
       }
       description
         "This type is for CATS CS-ID.";
       reference
         "RFC XXXX: YANG Data Model for CATS";
     }

     typedef csci-id {
       type union {
         type uint32;
         type inet:ipv4-address;
         type inet:ipv6-address;
       }
       description
         "This type is for CATS CSCI-ID.";
       reference
         "RFC XXXX: YANG Data Model for CATS";
     }

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     grouping service-policy-type {
       description
         "service policy type";
       leaf policy-type {
         type enumeration {
           enum base-on-affinity {
             value 0;
             description "base on affinity";
           }
           enum base-on-sm-only {
             value 1;
             description "base on service metric only";
           }
           enum base-on-nm-only {
             value 2;
             description "base on network metric only";
           }
           enum base-on-sm-nm {
             value 3;
             description
               "base on the combination of service metric and network
                metric";
           }
         }
         description "service policy type";
       }
     }

     augment "/rt:routing" {
       description
         "This augments the CATS configuration.";
       container cats {
         description
           "Support for the CATS configuration.";
         container base {
           description
             "CATS base configuration.";
           leaf enable {
             type boolean;
             description
               "enable CATS";
           }
           leaf update-interval {
             type uint32;
             units "seconds";
             default "30";
             description

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               "Update interval of CATS metric. A value of 0
                indicates that metrics are sent only when a
                significant change occurs and not on a periodic
                basis.";
           }
           leaf metric-limits {
             type uint32;
             description
               "CATS metric entry limit";
           }
           leaf flow-limits {
             type uint32;
             description
               "CATS flow entry limit";
           }
           leaf flow-timeout {
             type uint32;
             units "seconds";
             default "120";
             description
               "CATS flow timeout when no flow. A value of 0 means
                that the flow does not time out due to inactivity
                (i.e., infinite timeout), and must be terminated
                explicitly (e.g., via signaling or administrative
                action).";
           }
           container service-policy {
             description
               "CATS service policy";
             leaf cs-id {
               type cs-id;
               description
                 "cs-id";
             }
             uses service-policy-type;
           }
         }

         container traffic-classifiers {
           description
             "CATS traffic-classifier feature";
           list traffic-classifier {
             key "cs-id";
             description
               "CATS traffic-classifier feature";
             leaf cs-id {
               type cs-id;
               description

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                 "CATS CS-ID";
             }
             leaf description {
               type string;
               description
                 "description of this service, example: http";
             }
             leaf server-port {
               type uint16;
               description
                 "server-port of the service, matches the
                  destination port in the IP packets of data
                  flows destined for the service.";
             }
             leaf protocol {
               type uint8;
               description
                 "protocol of the service.";
             }
           }
         }

         container service-metrics {
           description
             "CATS service metric entry";
           list service-metric {
             key "cs-id csci-id source-type";
             description
               "CATS service metric entry";
             leaf cs-id {
               type cs-id;
               description
                 "CATS cs-id";
             }
             leaf csci-id {
               type csci-id;
               description
                 "CATS csci-id";
             }
             leaf source-type {
               type enumeration {
                 enum static {
                   value 0;
                   description "static configuration";
                 }
               }
               description
                 "source-type of the service compute-metric";

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             }
             leaf priority {
               type uint8;
               description
                 "server priority, the smaller the value,
                  the higher the priority.";
             }
             leaf affinity {
               type uint8;
               description
                 "server affinity, the higher the value,
                  the higher the affinity.";
             }
             leaf location {
               type inet:ip-address;
               description
                 "server location";
             }
             container metrics {
               description
                 "service metric";
               list metric {
                 key "metric-type";
                 description "Different types of service.";
                 leaf metric-type {
                   type enumeration {
                     enum delay {
                       value 0;
                       description
                         "Calculate the metric based on transmission
                          delay, where the metric value is the delay
                          time in milliseconds.";
                     }
                     enum service-ratio {
                       value 1;
                       description
                         "Calculate the metric based on business
                          capacity, where the metric value is the
                          current capacity percentage.";
                     }
                     enum memory-ratio {
                       value 2;
                       description
                         "Calculate the metric based on memory
                          utilization percentage, where the metric
                          value is the current memory utilization
                          percentage";
                     }

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                   }
                   description "metric type";
                   reference
                     "RFC YYYY: CATS Metrics Definition";
                 }
                 leaf metric-value {
                   type uint32;
                   description "metric value";
                 }
               }
             }
           }
         }
         container notify {
           description "event notify";
           leaf entry-limit-reached {
             type boolean;
             description "entry limit reached";
           }
           leaf flow-limit-reached {
             type boolean;
             description "flow entry limit reached";
           }
         }
       }
     }
   }
   <CODE ENDS>

5. Security Considerations

   The YANG module "ietf-cats" defines a data model designed to be
   accessed via YANG-based management protocols such as NETCONF
   [RFC6241] and RESTCONF [RFC8040]. These protocols have to use a
   secure transport layer (e.g., SSH [RFC4252], TLS [RFC8446], and QUIC
   [RFC9000]) and have to use mutual authentication.

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

   There are a number of data nodes defined in the ietf-cats.yang
   module that are writable/creatable/deletable (i.e., config true,
   which is the default). These data nodes may be considered sensitive
   or vulnerable in some network environments. Write operations (e.g.,
   edit-config) to these data nodes without proper protection can have

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   a negative effect on network operations. These are the subtrees and
   data nodes and their sensitivity/vulnerability:

   *  /cats:base/cats:enable

   *  /cats:base/cats:update-interval

   *  /cats:base/cats:metric-limits

   *  /cats:base/cats:flow-limits

   *  /cats:base/cats:flow-timeout

   *  /cats:base/cats:service-policy/cats:cs-id

   *  /cats:base/cats:service-policy/cats:policy-type

   *  /cats:traffic-classifiers/cats:traffic-classifier/cats:cs-id

   *  /cats:traffic-classifiers/cats:traffic-classifier
      /cats:description

   *  /cats:traffic-classifiers/cats:traffic-classifier
      /cats:server-port

   *  /cats:traffic-classifiers/cats:traffic-classifier/cats:protocol

   *  /cats:service-metrics/cats:service-metric/cats:cs-id

   *  /cats:service-metrics/cats:service-metric/cats:csci-id

   *  /cats:service-metrics/cats:service-metric/cats:source-type

   *  /cats:service-metrics/cats:service-metric/cats:priority

   *  /cats:service-metrics/cats:service-metric/cats:affinity

   *  /cats:service-metrics/cats:service-metric/cats:location

   *  /cats:service-metrics/cats:service-metric/cats:metrics
      /cats:metric/cats:metric-type

   *  /cats:service-metrics/cats:service-metric/cats:metrics
      /cats:metric/cats:metric-value

   For these augmentations to ietf-routing.yang, the ability to
   delete, add, and modify CATS base configuration, traffic classifier

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   configuration and service metric configuration would allow traffic
   to be misrouted.

   Some of the readable data nodes in the ietf-cats.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:

   *  /cats:notify/cats:entry-limit-reached

   *  /cats:notify/cats:flow-limit-reached

   Exposing the notification will expose the CATS table information of
   the network device. This may be undesirable due to the fact that
   such exposure may facilitate other attacks. Additionally, network
   operators may consider their CATS table information to be sensitive
   confidential data.

   All the security considerations for writable and readable data nodes
   defined in [RFC8349] apply to the augmentations described herein.

6. IANA Considerations

   The IANA is requested to assign the following URI in the "IETF XML
   Registry" [RFC3688]:

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

   This document registers the following YANG module in the "YANG
   Module Names" registry [RFC6020]:

     Name:       ietf-cats
     Maintained by IANA?  N
     Namespace:  urn:ietf:params:xml:ns:yang:ietf-cats
     Prefix:     cats
     Reference:  RFC XXXX

7. References

7.1. Normative References

   [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>.

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

   [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for
             the Network Configuration Protocol (NETCONF)", RFC 6020,
             DOI 10.17487/RFC6020, October 2010, <https://www.rfc-
             editor.org/info/rfc6020>.

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

   [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>.

   [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>.

   [RFC8344] Bjorklund, M., "A YANG Data Model for IP Management", RFC
             8344, DOI 10.17487/RFC8344, March 2018, <https://www.rfc-
             editor.org/info/rfc8344>.

   [RFC8349] Lhotka, L., Lindem, A., and Y. Qu, "A YANG Data Model for
             Routing Management (NMDA Version)", RFC 8349, DOI
             10.17487/RFC8349, March 2018, <https://www.rfc-
             editor.org/info/rfc8349>.

   [RFC8407] Bierman, A., "Guidelines for Authors and Reviewers of
             Documents Containing YANG Data Models", BCP 216, RFC 8407,
             DOI 10.17487/RFC8407, October 2018, <https://www.rfc-
             editor.org/info/rfc8407>.

   [RFC8639] Voit, E., Clemm, A., Gonzalez Prieto, A., Nilsen-Nygaard,
             E., and A. Tripathy, "Subscription to YANG Notifications",
             RFC 8639, DOI 10.17487/RFC8639, September 2019,
             <https://www.rfc-editor.org/info/rfc8639>.

   [RFC8641] Clemm, A. and E. Voit, "Subscription to YANG Notifications
             for Datastore Updates", RFC 8641, DOI 10.17487/RFC8641,
             September 2019, <https://www.rfc-editor.org/info/rfc8641>.

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7.2. Informative References

   [I-D.ietf-cats-framework] C. Li.,Z. Du.,M. Boucadair.,L. M.
             Contreras., J. Drake., "A Framework for Computing-Aware
             Traffic Steering (CATS)", draft-ietf-cats-framework-
             13(work in progress), September 2025.

   [RFC4252] Ylonen, T. and C. Lonvick, Ed., "The Secure Shell (SSH)
             Authentication Protocol", RFC 4252, DOI 10.17487/RFC4252,
             January 2006, <https://www.rfc-editor.org/info/rfc4252>.

   [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>.

   [RFC7895] Bierman, A., Bjorklund, M., and K. Watsen, "YANG Module
             Library", RFC 7895, DOI 10.17487/RFC7895, June 2016,
             <https://www.rfc-editor.org/info/rfc7895>.

   [RFC7951] Lhotka, L., "JSON Encoding of Data Modeled with YANG", RFC
             7951, DOI 10.17487/RFC7951, August 2016, <https://www.rfc-
             editor.org/info/rfc7951>.

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

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

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

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

   [RFC9000] Iyengar, J., Ed. and M. Thomson, Ed., "QUIC: A UDP-Based
             Multiplexed and Secure Transport", RFC 9000, DOI
             10.17487/RFC9000, May 2021, <https://www.rfc-
             editor.org/info/rfc9000>.

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Contributors

   TBD

Authors' Addresses

   Huijuan Yao
   China Mobile
   No.32 XuanWuMen West Street
   Beijing
   100053
   China
   Email: yaohuijuan@chinamobile.com

   Changwang Lin
   New H3C Technologies
   Beijing
   China
   Email: linchangwang.04414@h3c.com

   Zhenqiang Li
   China Mobile
   China
   Email: lizhenqiang@chinamobile.com

   Quan Xiong
   ZTE Corporation
   Email: xiong.quan@zte.com.cn

   Luis M. Contreras
   Telefonica
   Spain
   Email: luismiguel.contrerasmurillo@telefonica.com

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