YANG Models for Quality of Service (QoS) in IP networks

YANG Models for Quality of Service (QoS) in IP networks Cisco Systems Kloud Services Juniper Networks The MITRE Corporation This document describes a YANG model for management of Quality of Service (QoS) in IP networks.

Introduction This document defines a YANG 1.1 model for Quality of Service (QoS) configuration and operational parameters as they relate to IP networks. Traffic Policy module defines the basic building blocks to define a classifier, policy and target. QoS Action module defines QoS action related parameters. Differentiated Servicers (Diffserv) policy, Queue policy and Schedular policy modules augments Traffic policy with various packet match and action parameters. Each of these policies are defined as separate modules. The Diffserv module is based on Diffserv architecture, and various references have been made to available standard architecture documents. QoS statistics counters are defined in QoS Operational module. While there are other approaches to offering QoS services, this document focuses on Diffserv as the approach for providers to offer services to different customers based on their network QoS objectives. The DSCP markings are applied by upstream node or by the edge router on entry to the Diffserv domain. The traffic streams are differentiated based on Diffserv Code Points (DSCP) carried in the IP header of each packet and per-hop-behavior according to the DSCP marking is applied. The YANG modules in this document conform to the Network Management Datastore Architecture (NMDA) . Tree diagrams used in this document follow the notation defined in YANG Tree Diagrams .

Note to RFC Editor Editorial Note: (To be removed by RFC Editor) This draft contains several placeholder values that need to be replaced with finalized values at the time of publication. Please apply the following replacements:

"XXXX" --> the assigned RFC value for this draft both in this draft and in the yang modules under the revision statement.
The "revision" date in model, in the format XXXX-XX-XX, needs to be updated with the date the draft gets approved.

Terminology 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 when, and only when, they appear in all capitals, as shown here.

Definitions and Acronyms This document uses definitions and acronyms defined in Definitions of the Differentiated Services Field (DS Field) in the IPv4 and IPv6 Headers , An Architecture for Differentiated Services , and other documents. Here are some of them.

Active Queue Management (AQM): An activity that marks or drops packets before the queue is full.
Behavior Aggregate (BA): A DS behavior aggregate.
Classifier: an entity which selects packets based on the content of packet headers according to defined rules.
CoDel: Controlled Delay AQM algorithm
DS behavior aggregate: A collection of packets with the same DS codepoint crossing a link in a particular direction.
DS code point: A specific value of the DSCP portion of the DS field, used to select a PHB.
Diffserv: Differentiated Services enhancements to the Internet protocol are intended to enable scalable service discrimination in the Internet without the need for per-flow state and signaling at every hop. A variety of services may be built from a small, well- defined set of building blocks which are deployed in network nodes.
DSCP: Differentiated Services Code Point
ECN: Explicit Congestion Notification
FQ-CoDel: Flow Queue Controlled Delay AQM algorithm
Marking: the process of setting the DS codepoint in a packet based on defined rules; pre-marking, re-marking.
Metering: the process of measuring the temporal properties (e.g., rate) of a traffic stream selected by a classifier. The instantaneous state of this process may be used to affect the operation of a marker, shaper, or dropper, and/or may be used for accounting and measurement purposes.
MF Classifier: A multi-field (MF) classifier which selects packets based on the content of some arbitrary number of header fields; typically some combination of source address, destination address, DS field, protocol ID, source port and destination port.
Per-Hop-Behavior (PHB): A description of the externally observable forwarding treatment applied at a differentiated services- compliant node to a behavior aggregate . The description of a PHB SHOULD be sufficiently detailed to allow the construction of predictable services, as documented in .
Policing: the process of discarding packets (by a dropper) within a traffic stream in accordance with the state of a corresponding meter enforcing a traffic profile.
Policy: A set of rules each with a set of conditions and a set of actions.
RED: Random Early Detection
Shaping: the process of delaying packets within a traffic stream to cause it to conform to some defined traffic profile.
Target: The network physical or logical element (e.g., interface or device) where a Policy is applied.
Traffic-Group: a logical collection of packets or flows that share similar service requirements and are treated collectively for traffic management purposes, including prioritization, shaping, policing, or resource reservation.
WRED: Weighted Random Early Detection

QoS Model Design The overall objective of this model design is to offer a base set of modules that can then be further augmented to provide other models, such as Differentiated Services (Diffserv) and Policy Based Routing (PBR). Those models would augment the base modules defined in this draft to define their own model. This document defines one such model, Diffserv. The design also takes into consideration that vendors might want to extend the model to add their own extensions, such as the Traffic Policy module, to provide constructs of policy for different QoS functionalities."

QoS Yang Modules Layout The above figure depicts the design of the QoS model. It uses Traffic Policy and QoS Action as base modules, which are augmented by the remaining modules on the top to define different aspects of QoS. The Classifier is defined as part of Traffic Policy Module. A classifier consists of set of filters and an operation that is performed on those filters. Each filter defines a rule on a particular packet header or packet metadata field that dictate how the packet will be classified based on that particular field, e.g. whether it will be classified based on DSCP, or will be classified based on source IPv4 address prefix. The operation defines whether these filters are logically AND or OR. The filters may be based on a combination of values or range of values of different packet header fields or packet metadata fields. An example of how these filter definitions are used can be seen in the Diffserv model. The Diffserv model augments the filter node in the Classifier to add in Diffserv specific filter parameters. One or more packet conditioning functions may be applied to a classifier which may drop, mark, or delay packets. These are defined in the QoS Action module. A set of classifiers with corresponding conditioning functions when arranged in order of priority represent a QoS policy. These policies are defined in Traffic Policy module. The QoS Action module defines marking, metering and queuing. QoS actions are configured in line or referred to in Diffserv, Queuing, and Scheduling Policy modules. A Meter meters each packet and passes the packet and the metering result to the Marker. Meter is modeled based on commonly used algorithms in industry, A Single Rate Three Color Marker (srTCM) , A Two Rate Three Color Marker (trTCM) , and A Single Rate Two Color Marker. Different vendors can extend it with other types of meters as well. Meter is defined in QoS Action module. Queue Policy module allows queues to be referred in a policy. The match is based on Traffic Group and action parameters are used as defined in QoS Action module. Scheduling Policy module defines a set of scheduling parameters and associates Queue Policy with it. QoS counters are defined in QoS Operational (ietf-qos-oper) module. It includes counters for Classifiers, Meters and Queues associated with a QoS policy applied in each direction of traffic. To modularize and for reusability, grouping have been defined for various counters of Classifier, Meters and Queues. A Traffic Policy is applied to a Target. A Target is a network logical or physical interface or sub-interface. However, the groupings can be reused to define a traffic policy which then can be applied to any logical or physical entities such as a Policy to form hierarchical policies. In addition, ietf-qos-types module is defined which serves as the central repository for shared identities, groupings, and typedefs utilized across the entire QoS model. It defines the fundamental building blocks such as traffic direction, rate units, and filter types that ensure consistency between the other functional modules and future extensibility.

Diffserv Model Design Definition of the Differentiated Services Field (DS Field) in the IPv4 and IPv6 Headers describes the architecture as a simple model where traffic entering a network is classified and possibly conditioned at the boundary of the network and assigned a different Behavior Aggregate (BA). Each BA is identified by a specific value of DSCP, and is used to select a Per Hop Behavior (PHB) at the edge node as well as at the core of a DS domain. In a DiffServ-compliant node, the PHB is selected based on the DSCP value found in the IP header of an incoming packet. Specifically, a Behavior Aggregate (BA) classifier is used to map the DSCP to a particular PHB, which determines the externally observable forwarding treatment the packet receives at that hop. The mapping of a DSCP to a PHB is local to each node. While a single DSCP identifies a Behavior Aggregate (BA) across the network, different nodes may be configured to apply different PHBs to that same BA based on local policy and resource availability. Multiple DSCP values can be mapped to the same PHB at a single node. This allows for a simplified core configuration where various traffic streams (identified by different DSCPs at the edge) receive the same forwarding treatment within the backbone. This YANG model facilitates this by allowing the DiffServ module to augment the base Traffic Policy module. This enables the configuration of classifiers (like the BA classifier) that select packets based on DSCP ranges and associate them with specific actions (PHBs), such as marking, metering, or queuing, at each network interface. The packet classification policy identifies the subset of traffic which may receive a Diffserv by being conditioned or mapped. Packet classifiers select packets within a stream based on the content of some portion of the packet header. There are two types of classifiers, the BA classifier, and the Multi-Field (MF) classifier which selects packets based on a value which is combination of value or range of values of one or more header fields. Diffserv domain gateway router classifies and remarks packet to suit domain internal Diffserv policy and here RFC8436 must be respected. Diffserv Domain internal routers may classify by ranges of DSCPs. This allows keeping e.g. a backbone DS config simple and comprehensible. In the Diffserv Policy module, this packet classification is realized by augmenting the classifier in Traffic Policy module. Traffic conditioning includes metering, shaping and/or marking. A Meter is used to measure the traffic against a given traffic profile. The traffic profile specifies the temporal property of the traffic. A packet that arrives is first determined to be in or out of the profile, which will result in the action of marked, dropped or shaped. This is realized in vendor specific modules based on the parameters defined in action module. The metering parameters are augmented to the QoS policy module when metering is defined inline, and to the metering template when metering profile is referred in policy module.

A Single Rate Three Color Marker This document defines support for A Single Rate Three Color Marker (srTCM) , which is one of the components in a An Architecture for Differentiated Services . The srTCM meters a traffic stream and marks its packets according to three traffic parameters, Committed Information Rate (CIR), Committed Burst Size (CBS), and Excess Burst Size (EBS), to be either green, yellow, or red. A packet is marked green if it doesn't exceed the CBS, yellow if it does exceed the CBS, but not the EBS, and red otherwise.

A Two Rate Three Color Marker This document defines support for A Two Rate Three Color Marker (trTCM) , which is one of the components in a An Architecture for Differentiated Services . The trTCM meters a traffic stream and marks its packets according to two rates, Peak Information Rate (PIR), the Committed Information Rate (CIR), and their associated burst sizes to either green, yellow, or red. A packet is marked red if it exceeds the PIR. Otherwise, it is marked yellow or green depending on whether it exceeds or does not exceed the CIR.

YANG Modules Modules defined in this draft import definitions from Common YANG Data Types and A YANG Data Model for Interface Management .

Traffic Policy Module Traffic Policy module contains list of classifiers identified by a classifier name. Each classifier MAY contain a list of filters. While a single filter is sufficient for simple classification, like one would expect at a core interface, a list of filters allows for more sophisticated logic to be applied on the ingress edge nodes. This module also contains list of policy objects identified by a policy name and policy type which MUST be provided. Policy-type is of type identity and is populated in a vendor specific manner. With different values of policy types, each vendor MAY define their own construct of policy for different QoS functionalities. Each vendor MAY augment classifier entry in a policy definition with a set of actions. The module also augments A YANG Data Model for Interface Management module to add a target policy. A single policy of a particular policy-type can be applied on an interface in each direction of traffic. The figure below presents the tree diagram for the ietf-traffic- policy module. This module serves as the central framework for the QoS module, defining how Classifiers are associated with Actions (traffic treatment) with a Policy. It also includes the qos-target- poilcy, which facilitates the attachment of these Policies to specific network Targets, such as interfaces, in either the inbound or outbound direction.

ietf-traffic-policy abridged tree diagram /policies/policy/name ]]> WG List: Editor: Aseem Choudhary Editor: Mahesh Jethanandani "; description "This module contains a collection of YANG definitions for configuring QoS Traffic Policies. Copyright (c) 2023 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 (http://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX; see the RFC itself for full legal notices."; revision 2026-03-02 { description "Initial version."; reference "RFC XXXX: YANG Models for Quality of Service (QoS)."; } grouping filters { description "Filters types in a Classifier entry."; leaf type { type identityref { base qos-types:filter-type; } description "This leaf defines the type of filter."; } leaf logical-not { type boolean; description "This is logical-not operator for filter values and/or value ranges. When true, it indicates filter looks for absence of values and/or value ranges defined by the filter."; } } grouping generic-classifier-attr { description "Generic Classifier attributes like name, description, operation type."; leaf name { type string; description "A name for Classifier entry."; } leaf description { type string; description "Description statement for classifier entry."; } leaf filter-operation { type qos-types:match-operation-type; description "match-any or match-all filters."; } } grouping inline-attr { description "Attributes of inline classifier in a policy."; leaf filter-operation { type qos-types:match-operation-type; description "match-any or match-all filters."; } list filter { key "type logical-not"; uses filters; description "Filters configured inline in a policy."; } } container classifiers { description "List of classifier entries."; list classifier { key "name"; description "Each classifier entry contains a list of filters."; uses generic-classifier-attr; list filter { key "type logical-not"; uses filters; description "Filter entries for a classifier."; } } } container policies { description "List of policy templates."; list policy { key "name type"; description "Policy template."; leaf name { type string; description "A name for the policy."; } leaf type { type identityref { base qos-types:policy-type; } description "The type of policy."; } leaf description { type string; description "A description for policy."; } list classifier { key "name"; ordered-by user; description "Classifier configuration in a policy."; leaf name { type union { type string; type leafref { path "/traffic-policy:classifiers/" + "traffic-policy:classifier/traffic-policy:name"; } } description "A name for classifier entry."; } container inline { presence "This container is present for when the device is configured for inline classification."; uses inline-attr; description "Container for when an inline classification is desired."; } list action { key "type"; ordered-by user; description "List of action for a Classifier."; leaf type { type identityref { base qos-types:action-type; } description "Type of action."; } } } } } augment "/if:interfaces/if:interface" { description "Augments Interface module to add Target Entry."; list qos-target-policy { key "direction type"; description "Policy target for inbound or outbound direction."; leaf direction { type identityref { base qos-types:direction; } description "Direction of the traffic flow either inbound or outbound."; } leaf type { type identityref { base qos-types:policy-type; } description "Policy type."; } leaf name { type leafref { path "/traffic-policy:policies/" + "traffic-policy:policy/traffic-policy:name"; } mandatory true; description "A name for the Policy."; } } } } ]]>

: Figure 3: ietf-traffic-policy module

QoS Action Module QoS Action module includes actions such marking, metering, or queuing. Metering, marking, queuing, and scheduling actions are realized by augmenting the Traffic Policy module. Marking sets Diffserv codepoint value in the classified packet. The figure below depicts the tree diagram for the ietf-qos-action module. This module defines the common set of Actions that can be applied to traffic once it has been classified. These actions include fundamental QoS operations such as Marking (setting DSCP or precedence values), Metering, and Queuing. The structure is designed to be extensible, allowing for the addition of new action types as required by specific hardware capabilities.

ietf-qos-actions abridged tree diagram WG List: Editor: Aseem Choudhary Editor: Mahesh Jethanandani "; description "This module contains a collection of YANG definitions for configuring QoS actions. Copyright (c) 2023 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 (http://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX; see the RFC itself for full legal notices."; revision 2026-03-02 { description "Initial version"; reference "RFC XXXX: YANG Models for Quality of Service (QoS)."; } grouping rate-value-unit { leaf value { type uint64; description "Value for the rate that is configured, either in bits-per-second or percentage."; } leaf unit { type identityref { base qos-types:rate-unit-type; } default qos-types:bits-per-second; description "The unit for the value above, either in bits-per-second or percentage."; } description "Grouping for configuration of value and unit."; } grouping meter-action { description "Configuration of meter actions."; leaf action-type { type identityref { base qos-types:meter-action-type; } description "Action type for metering."; } leaf dscp-mark { type inet:dscp; must "../action-type = 'qos-types:action-mark'" { error-message "DSCP must be marked when action-type is action-mark."; } description "DSCP marking"; } leaf traffic-group-mark { type string; must "../action-type = 'qos-types:action-mark'" { error-message "Traffic-group must be marked when action-type is action-mark."; } description "A name to mark as a traffic group."; } } grouping single-rate-two-color-meter { container single-rate-two-color-meter { description "A container for Basic Single Rate Two Color Marker."; leaf committed-information-rate { type uint64; units "bytes-per-second"; description "The value for Committed Information Rate (CIR)."; } leaf committed-burst-size { type uint64; units "bytes"; description "The value for Committed Burst Size (CBS)."; } container conform-action { uses meter-action; description "A packet is marked conforming, or green if it does not exceed CIR."; } container exceed-action { uses meter-action; description "A packet is marked exceeding, or yellow if it does exceed CIR."; } } description "A Basic Single Rate Two Color Meter."; } grouping single-rate-three-color-meter { container single-rate-three-color-meter { description "Container that defines the Single Rate Three Color Meter (srTCM)."; leaf committed-information-rate { type uint64; units "bytes-per-second"; description "The value for Committed Information Rate (CIR)."; reference "RFC 2697: A Single Rate Three Color Marker."; } leaf committed-burst-size { type uint64; units "bytes"; description "The value for Committed Burst Size (CBS)."; reference "RFC 2697: A Single Rate Three Color Marker."; } leaf excess-burst-size { type uint64; units "bytes"; description "The value for Excess Burst Size (EBS)."; reference "RFC 2697: A Single Rate Three Color Marker."; } container conform-action { uses meter-action; description "A packet is marked conforming, or green if it does not exceed CBS."; reference "RFC 2697: A Single Rate Three Color Marker."; } container exceed-action { uses meter-action; description "A packet is marked exceeding, or yellow if it does exceed CBS, but not the EBS."; reference "RFC 2697: A Single Rate Three Color Marker."; } container violate-action { uses meter-action; description "A packet is marked violating, or red if it is exceeds both CBS and EBS."; reference "RFC 2697: A Single Rate Three Color Marker."; } } description "Singe Rate Three Color Meter (srTCM)."; reference "RFC 2697: A Single Rate Three Color Marker."; } grouping two-rate-three-color-meter { container two-rate-three-color-meter { description "A container that defines A Two Rate Three Color Meter (trTCM)."; leaf committed-information-rate { type uint64; units "bytes-per-second"; description "The value for Committed Information Rate (CIR)."; reference "RFC 2698: A Two Rate Three Color Marker."; } leaf committed-burst-size { type uint64; units "bytes"; description "The value for Committed Burst Size (CBS)."; reference "RFC 2698: A Two Rate Three Color Marker."; } leaf peak-information-rate { type uint64; units "bytes-per-second"; description "The value for Peak Information Rate (PIR)."; reference "RFC 2698: A Two Rate Three Color Marker."; } leaf peak-burst-size { type uint64; units "bytes"; description "The value for Peak Burst Size (PBS)."; reference "RFC 2698: A Two Rate Three Color Marker."; } container conform-action { uses meter-action; description "A packet is marked conforming, or green, if it does not exceed CIR."; reference "RFC 2698: A Two Rate Three Color Marker."; } container exceed-action { uses meter-action; description "A packet is marked exceeding, or yellow, if it exceeds CIR but not PIR."; reference "RFC 2698: A Two Rate Three Color Marker."; } container violate-action { uses meter-action; description "A packet is marked as violating, or red, if it exceeds both CIR and PIR."; reference "RFC 2698: A Two Rate Three Color Marker."; } } description "Container for a Two Rate Three Color Marker."; } grouping meter { choice meter-types { case single-rate-two-color-meter-type { uses single-rate-two-color-meter; } case single-rate-three-color-meter-type { uses single-rate-three-color-meter; } case two-rate-three-color-meter-type { uses two-rate-three-color-meter; } description "A meter action based on choice of meter action type."; } description "Meter attributes."; } container meters { description "List of meter templates."; list meter { key "name"; description "Meter entry template."; leaf name { type string; description "A name to identify the meter."; } uses meter; } } grouping meter-reference { container meter { leaf name { type leafref { path "/qos-action:meters/" + "qos-action:meter/qos-action:name"; } mandatory true; description "This leaf defines name of the meter referenced."; } leaf type { type identityref { base qos-types:meter-type; } mandatory true; description "This leaf defines type of the meter."; } description "The name and type for meter reference."; } description "Grouping to define meter reference."; } grouping qos-count { container qos-count { if-feature qos-types:qos-count; leaf qos-count-action { type empty; description "Take an action if this is defined."; } description "Container for whether to take an action for QoS count."; } description "The qos-count action grouping."; } grouping named-qos-count { container named-qos-count { if-feature qos-types:named-qos-count; leaf name { type string; description "A name for named QoS count."; } description "The named traffic counter action."; } description "The named traffic counter action grouping."; } grouping discard { container discard { leaf discard { type empty; description "If defined this enables discard action."; } description "Container for discard action."; } description "Grouping for discard action."; } grouping priority { container priority { leaf level { type uint8; description "Priority level."; } description "Container for priority."; } description "Grouping for priority."; } grouping min-rate { container min-rate { uses rate-value-unit; description "Minimum guaranteed bandwidth."; } description "Grouping for minimum rate."; } grouping dscp-marking { container dscp { leaf dscp { type inet:dscp; description "DSCP marking."; } description "Container for DSCP marking."; } description "Grouping for DSCP marking."; } grouping traffic-group-marking { container traffic-group { leaf traffic-group { type string; description "A name for traffic group."; } description "Container for traffic group marking container."; } description "Grouping for traffic group marking."; } grouping child-policy { container child-policy { if-feature qos-types:child-policy; leaf name { type string; description "A name for hierarchical policy."; } description "Hierarchical Policy configuration container."; } description "Grouping of Hierarchical Policy configuration."; } grouping max-rate { container max-rate { uses rate-value-unit; leaf burst-value { type uint64; description "Burst value in bytes."; } leaf burst-unit { type identityref { base qos-types:burst-unit-type; } default qos-types:bytes; description "Burst value in bytes or milliseconds, with a default of bytes."; } description "Maximum rate attributes container."; } description "Grouping for maximum rate attributes."; } grouping red-config-parameters { leaf min-threshold-val { type uint64; description "Minimum value of RED threshold."; } leaf min-threshold-unit { type identityref { base qos-types:red-threshold-unit; } default qos-types:red-threshold-bytes; description "The unit for minimum RED threshold value, with the default of bytes."; } leaf max-threshold-val { type uint64; description "Maximum value of RED threshold."; } leaf max-threshold-unit { type identityref { base qos-types:red-threshold-unit; } default qos-types:red-threshold-bytes; description "The unit for maximum RED threshold value, with the default of bytes."; } leaf weight { type uint8; description "The decay factor for the average queue size calculation. The numbers is a 2's exponent."; } leaf max-probability-val { type uint64; description "Value of maximum probability value. This value need be interpreted along with max-probability-unit"; } leaf max-probability-unit { type identityref { base qos-types:probability-unit; } default qos-types:probability-pc; description "Probability unit type, with a default of percentage."; } description "Random Early Detect (RED) configuration parameters."; } grouping codel-config-parameters { leaf target { type uint64; units "microseconds"; default 5000; description "Target time in microseconds spent by each packet in queue."; } leaf interval { type uint64; units "microseconds"; default 100000; description "The time in microsecond for minimum interval for congestion to persist before algorithm kicks in. "; } description "CoDel configuration parameters."; } grouping queue { container queue { uses priority; uses min-rate; uses max-rate; container algorithmic-drop { choice drop-algorithm { case tail-drop { container tail-drop { leaf tail-drop { type empty; description "When defined, tail drop algorithm is enabled."; } description "Tail Drop configuration container."; } description "Tail Drop choice."; } case red { container red { uses red-config-parameters; leaf ecn-enabled { type boolean; default "false"; description "ECN is enabled on the queue."; } description "Random Early Detect (RED) configuration."; } } case wred { container wred { list wred { key "profile"; leaf profile { type uint8; description "Profile id of each WRED profile."; } leaf color-type { type identityref { base qos-types:wred-color-type; } default qos-types:wred-color-dscp; description "WRED color-type of each profile."; } list color-val { key "min max"; leaf min { type uint8; description "Minimum value of color types."; } leaf max { type uint8; description "Maximum value of color types."; } description "List of color markings which constitute a traffic profile."; } uses red-config-parameters; description "List of RED profiles each with its own threshold values."; } leaf ecn-enabled { type boolean; default "false"; description "When configure as true, ECN is enabled on the queue."; } description "Weighted Random Early Detect (WRED) configuration."; } } case codel { container codel { uses codel-config-parameters; leaf ecn-enabled { type boolean; default "false"; description "When configure as true, ECN is enabled on the queue."; } description "CoDel configuration."; } } case fq-codel { container fq-codel { uses codel-config-parameters; leaf flows { type uint64; default 1024; description "The maximum number of flow queues."; } leaf ecn-enabled { type boolean; default "false"; description "ECN is enabled on the queue."; } description "FQ-CoDel configuration."; } } description "Choice of Drop Algorithm."; } description "Algorithmic Drop configuration container."; } description "Queue configuration container."; } description "Queue grouping."; } container queues { description "List of queue templates."; list queue { key "name"; description "Queue entry template."; leaf name { type string; description "A name identifying this queue template"; } uses queue; } } grouping queue-reference { container queue-reference { leaf queue-name { type leafref { path "/qos-action:queues/" + "qos-action:queue/qos-action:name"; } mandatory true; description "This leaf defines name of the queue template referenced."; } description "Queue template reference."; } description "Queue template reference grouping."; } grouping scheduler { container scheduler { uses min-rate; uses max-rate; description "Scheduler configuration container."; } description "Scheduler configuration grouping."; } } ]]>

: Figure 5: ietf-qos-actions module

Diffserv Module Diffserv module augments Traffic Policy module to enable diffrentiated services for different types of packets. The figure below presents the tree diagram for the ietf-diffserv module. This module augments the base ietf-traffic-policy module to enable Differentiated Services (Diffserv) for various packet types. It adds several filter parameters to the traffic policy's classifiers, as well as, various action parameters that can be applied within a policy's classifier.

module: ietf-diffserv

ietf-diffserv abridged tree diagram WG List: Editor: Aseem Choudhary Editor: Mahesh Jethanandani "; description "This module contains a collection of YANG definitions for configuring Diffserv specification implementations. Copyright (c) 2023 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 (http://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX; see the RFC itself for full legal notices."; revision 2026-03-02 { description "Initial version."; reference "RFC XXXX: A YANG Model for Quality of Service (QoS)."; } grouping dscp { list dscp { key "min max"; description "List of DSCP ranges."; leaf min { type inet:dscp; description "Minimum value of DSCP min-max range."; } leaf max { type inet:dscp; must ". >= ../min" { error-message "max must be greater than or equal to min."; } description "Maximum value of DSCP min-max range."; } } description "Filter grouping containing list of DSCP ranges."; } grouping source-ipv4-prefix { leaf-list source-ipv4-prefix { type inet:ipv4-prefix; description "List of source IPv4 prefixes."; } description "Filter grouping containing list of source IPv4 prefixes."; } grouping destination-ipv4-prefix { leaf-list destination-ipv4-prefix { type inet:ipv4-prefix; description "List of destination IPv4 prefixes."; } description "Filter grouping containing list of destination IPv4 prefixes."; } grouping source-ipv6-prefix { leaf-list source-ipv6-prefix { type inet:ipv6-prefix; description "List of source IPv6 prefixes."; } description "Filter grouping containing list of source IPv6 prefixes."; } grouping destination-ipv6-prefix { leaf-list destination-ipv6-prefix { type inet:ipv6-prefix; description "List of destination IPv6 prefixes."; } description "Filter grouping containing list of destination IPv6 prefixes."; } grouping source-port { list source-port { key "min max"; description "List of ranges of source port."; leaf min { type inet:port-number; description "Minimum value of source port range."; } leaf max { type inet:port-number; must ". >= ../min" { error-message "max must be greater than or equal to min."; } description "Maximum value of source port range."; } } description "Filter grouping containing list of source port ranges."; } grouping destination-port { list destination-port { key "min max"; description "List of min-max range of destination ports."; leaf min { type inet:port-number; description "Minimum value of destination port."; } leaf max { type inet:port-number; must ". >= ../min" { error-message "max must be greater than or equal to min."; } description "Maximum value of destination port range."; } } description "Filter grouping containing list of destination port ranges."; } grouping protocol { list protocol { key "min max"; description "List of ranges of protocol values. Protocol refers to the value in the protocol field of the IPv4 header and value in the 'next-header' field of IPv6 header. In IPv6 header, 'next-header' field indicates first extension header or the protocol in the 'upper-layer' header."; reference "RFC 791: Internet Protocol RFC 8200: Internet Protocol, Version 6 (IPv6) Specification."; leaf min { type inet:protocol-number; description "Minimum value of protocol range."; } leaf max { type inet:protocol-number; must ". >= ../min" { error-message "max must be greater than or equal to min."; } description "Maximum value of protocol range."; } } description "Filter grouping containing list of protocol ranges."; } grouping traffic-group { container traffic-group { leaf name { type string ; description "This leaf defines name of the traffic group referenced."; } description "Traffic group container."; } description "Traffic group grouping."; } grouping filter-match-all { container match-all { leaf action { type empty; description "When set, the filter matches all packets."; } description "The match all action."; } description "The match all filter grouping."; } augment "/traffic-policy:classifiers/traffic-policy:classifier" + "/traffic-policy:filter" { choice filter-param { description "Choice of filter types."; case dscp { uses dscp; description "Filter containing list of DSCP ranges."; } case source-ipv4-prefix { uses source-ipv4-prefix; description "Filter containing list of source IPv4 prefixes."; } case destination-ipv4-prefix { uses destination-ipv4-prefix; description "Filter containing list of destination IPv4 prefix."; } case source-ipv6-prefix { uses source-ipv6-prefix; description "Filter containing list of source IPv6 prefixes."; } case destination-ipv6-prefix { uses destination-ipv6-prefix; description "Filter containing list of destination IPv6 prefix."; } case source-port { uses source-port; description "Filter containing list of source-port ranges."; } case destination-port { uses destination-port; description "Filter containing list of destination-port ranges."; } case protocol { uses protocol; description "Filter Type Protocol."; } case traffic-group { uses traffic-group; description "Filter Type traffic-group."; } case filter-match-all { uses filter-match-all; description "When the filter type is set to match all packets."; } } description "Augments QoS classifier to add in Diffserv filters."; } augment "/traffic-policy:policies/traffic-policy:policy" + "/traffic-policy:classifier/traffic-policy:inline" + "/traffic-policy:filter" { when "derived-from-or-self(../../../traffic-policy:type, " + "'qos-types:ipv4-diffserv-policy-type') or " + "derived-from-or-self(../../../traffic-policy:type, " + "'qos-types:ipv6-diffserv-policy-type') or " + "derived-from-or-self(../../../traffic-policy:type, " + "'qos-types:diffserv-policy-type')" { description "If policy type is v4, v6 or default Diffserv, this filter can be used."; } choice filter-params { description "Choice of action types."; case dscp { uses dscp; description "Filter containing list of DSCP ranges."; } case source-ipv4-prefix { when "derived-from-or-self(/traffic-policy:policies/" + "traffic-policy:policy/traffic-policy:type, " + "'qos-types:ipv6-diffserv-policy-type')" { description "If policy type is v6, this filter cannot be used."; } uses source-ipv4-prefix; description "Filter containing list of source IPv4 prefixes."; } case destination-ipv4-prefix { when "derived-from-or-self(/traffic-policy:policies" + "/traffic-policy:policy/traffic-policy:type, " + "'qos-types:ipv6-diffserv-policy-type')" { description "If policy type is v6, this filter cannot be used."; } uses destination-ipv4-prefix; description "Filter containing list of destination IPv4 prefix."; } case source-ipv6-prefix { when "derived-from-or-self(/traffic-policy:policies" + "/traffic-policy:policy/traffic-policy:type, "+ "'qos-types:ipv4-diffserv-policy-type')" { description "If policy type is v4, this filter cannot be used."; } uses source-ipv6-prefix; description "Filter containing list of source IPv6 prefixes."; } case destination-ipv6-prefix { when "derived-from-or-self(/traffic-policy:policies" + "/traffic-policy:policy/traffic-policy:type, " + "'qos-types:ipv4-diffserv-policy-type')" { description "If policy type is v4, this filter cannot be used."; } uses destination-ipv6-prefix; description "Filter containing list of destination IPv6 prefix."; } case source-port { uses source-port; description "Filter containing list of source-port ranges."; } case destination-port { uses destination-port; description "Filter containing list of destination-port ranges."; } case protocol { uses protocol; description "Filter Type Protocol."; } case traffic-group { uses traffic-group; description "Filter Type traffic-group."; } case filter-match-all { uses filter-match-all; description "When the filter type is set to match all packets."; } } description "Augments Diffserv Classifier with common filter types."; } augment "/traffic-policy:policies/traffic-policy:policy/" + "traffic-policy:classifier/traffic-policy:action" { when "derived-from-or-self(../../traffic-policy:type, " + "'qos-types:ipv4-diffserv-policy-type') or " + "derived-from-or-self(../../traffic-policy:type, " + "'qos-types:ipv6-diffserv-policy-type') or " + "derived-from-or-self(../../traffic-policy:type, " + "'qos-types:diffserv-policy-type')" { description "If policy type is v4, v6 or default Diffserv, these actions can be used."; } description "Augments Diffserv Policy with action configuration."; choice action-params { description "Choice of different action parameters that can be taken."; case dscp-marking { uses qos-action:dscp-marking; } case meter-inline { uses qos-action:meter; } case meter-reference { uses qos-action:meter-reference; } case traffic-group-marking { uses qos-action:traffic-group-marking; } case child-policy { if-feature qos-types:child-policy; uses qos-action:child-policy; } case qos-count { if-feature qos-types:qos-count; uses qos-action:qos-count; } case named-qos-count { if-feature qos-types:named-qos-count; uses qos-action:named-qos-count; } case queue-inline { uses qos-action:queue; } case scheduler-inline { uses qos-action:scheduler; } } } } ]]>

: Figure 7: ietf-diffserv module

QoS Operational Module QoS Operational module contains all operational statistics. It contains statistics related to classifier, metering, queueing. Classifier statistics consist of list of classifier entries identified by a classifier entry name. Classifier counters include matched packets and bytes, and average rate of traffic matching a particular classifier. Metering statistics consist of meters identified by an identifier. Metering counters include conform, exceed, violate, drop packets, and bytes. Queuing counters include instantaneous, peak, average queue length, as well as output conform, exceed, tail drop packets and bytes. In addition, Named statistics is defined as statistics which is tagged by a name. This could be aggregated or non-aggregated. Aggregated named statistics is defined as counters which are aggregated across classifier entries in a policy applied to an interface in a particular direction. Non-aggregated named statistics are counters of classifier, metering or queuing which have the same tag name but counts are maintained separately. A clear action is provided to clear all statistics or statistics of a particular kind. The figure below shows the tree structure for the ietf-qos-oper module. This module is dedicated to providing visibility into the real-time performance of QoS policies. It contains operational state data and statistics, organized by classifier, meter, and queue. This includes 'named' counters, which allow operators to track traffic statistics across selected classifiers, meters and queues.

module: ietf-qos-oper

ietf-qos-oper abridged tree diagram WG List: Editor: Aseem Choudhary Editor: Mahesh Jethanandani "; description "This module contains a collection of YANG definitions for QoS operational specification. Copyright (c) 2023 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 (http://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX; see the RFC itself for full legal notices."; revision 2026-03-02 { description "Initial version."; reference "RFC XXXX: YANG Models for Quality of Service (QoS)."; } grouping classifier-stats { description "Statistics for a classifier."; leaf name { type string; description "A identifier for Classifier name."; } leaf classified-pkts { type yang:zero-based-counter64; description "Number of total packets filtered for a classifier."; } leaf classified-bytes { type yang:zero-based-counter64; description "Number of total bytes filtered for a classifier."; } leaf classified-rate { type yang:gauge64; units "bits-per-second"; description "Rate of average data flow through a classifier."; } } grouping queuing-stats { description "Statistics for a queue."; leaf queue-id { type string; description "A identifier for the Queue."; } leaf transmit-pkts { type yang:zero-based-counter64; description "Number of packets transmitted from queue."; } leaf transmit-bytes { type yang:zero-based-counter64; description "Number of bytes transmitted from queue."; } leaf queue-current-size-bytes { type yang:gauge64; description "Number of bytes currently buffered."; } leaf queue-average-size-bytes { type yang:gauge64; description "Average queue size in number of bytes."; } leaf queue-peak-size-bytes { type yang:gauge64; description "Peak buffer queue size in bytes."; } leaf tail-drop-pkts { type yang:zero-based-counter64; description "Total number of packets tail-dropped."; } leaf tail-drop-bytes { type yang:zero-based-counter64; description "Total number of bytes tail-dropped."; } container red-statistics { leaf drop-pkts { type yang:zero-based-counter64; description "Total number of packets dropped because of RED."; } leaf drop-bytes { type yang:zero-based-counter64; description "Total number of bytes dropped because of RED."; } leaf ecn-marked-pkts { type yang:zero-based-counter64; description "Total number of packets that were marked with ECN because of RED."; } leaf ecn-marked-bytes { type yang:zero-based-counter64; description "Total number of bytes that were marked with ECN because of RED."; } list wred-stats { config false; description "QoS WRED statistics."; leaf profile { type uint8; description "Profile identifier for each color of traffic."; } leaf drop-pkts { type yang:zero-based-counter64; description "Total number of packets dropped because of WRED."; } leaf drop-bytes { type yang:zero-based-counter64; description "Total number of bytes dropped because of WRED."; } leaf ecn-marked-pkts { type yang:zero-based-counter64; description "Total number of packets that were marked with ECN because of WRED."; } leaf ecn-marked-bytes { type yang:zero-based-counter64; description "Total number of bytes that were marked with ECN because of WRED."; } } description "Container of all RED statistics."; } container codel-statistics { leaf drop-pkts { type yang:zero-based-counter64; description "Total number of packets dropped because of CoDel or FQ-CoDel."; } leaf drop-bytes { type yang:zero-based-counter64; description "Total number of bytes dropped because of CoDel or FQ-CoDel."; } leaf ecn-marked-pkts { type yang:zero-based-counter64; description "Total number of packets that were marked with ECN because of CoDel or FQ-CoDel."; } leaf ecn-marked-bytes { type yang:zero-based-counter64; description "Total number of bytes that were marked with ECN because of CoDel or FQ-CoDel."; } leaf new-flow-count { type yang:zero-based-counter64; description "Total number of flows that FQ-CoDel has identified and is managing or has managed."; } description "Container of all CoDel or FQ-CoDel statistics."; } } grouping metering-stats { description "Statistics for a meter."; leaf meter-id { type string; description "A identifier that identifies this set of metering statistics."; } leaf conform-pkts { type yang:zero-based-counter64; description "Number of packets that conform to the rate and burst."; } leaf conform-bytes { type yang:zero-based-counter64; description "Total bytes count that conform to the rate and burst."; } leaf conform-rate { type yang:gauge64; units "bits-per-second"; description "Traffic Rate measured as conformimg."; } leaf exceed-pkts { type yang:zero-based-counter64; description "Number of packets that exceed the peak rate and peak burst."; } leaf exceed-bytes { type yang:zero-based-counter64; description "Total number of bytes which exceed the peak rate and peak burst."; } leaf exceed-rate { type yang:gauge64; units "bits-per-second"; description "Traffic Rate measured as exceeding."; } leaf violate-pkts { type yang:zero-based-counter64; description "Number of packets that were beyond peak rate and peak burst."; } leaf violate-bytes { type yang:zero-based-counter64; description "Total number of bytes which were beyond peak rate and peak burst."; } leaf violate-rate { type yang:gauge64; units "bits-per-second"; description "Traffic Rate measured as violating."; } leaf drop-pkts { type yang:zero-based-counter64; description "Number of packets dropped by meter."; } leaf drop-bytes { type yang:zero-based-counter64; description "Number of bytes dropped by meter."; } } augment "/if:interfaces/if:interface" { description "Augments interface module to add QoS Target entry."; container qos-interface-statistics { config false; description "QoS Interface statistics."; list stats-per-direction { description "QoS interface statistics in ingress or egress direction."; leaf direction { type identityref { base qos-types:direction; } description "Direction of the traffic flow. Either ingress or egress."; } leaf policy-name { type string; description "Policy name for single level policy as well as for Hierarchical policies. For Hierarchical policies, this represent relative path as well as the last level policy name."; } list classifier { description "Statistics for each Classifier in a Policy applied in a particular direction."; uses classifier-stats; } list named { description "Statistics for a statistics-name."; leaf name { type string; description "A name for statistics."; } container aggregated { description "Matched aggregated statistics for a statistics-name."; leaf pkts { type yang:zero-based-counter64; description "Number of total matched packets associated with a statistics name."; } leaf bytes { type yang:zero-based-counter64; description "Number of total matched bytes associated with a statistics name."; } leaf rate { type yang:gauge64; units "bits-per-second"; description "Rate of average matched data which is associated to a statistics name."; } } container non-aggregated { description "Statistics for non-aggregated statistics-name."; list classifier { description "Statistics for each Classifier in a Policy applied in a particular direction."; uses classifier-stats; } list metering { description "Statistics for each Meter associated with the Policy."; reference "RFC2697: A Single Rate Three Color Marker RFC2698: A Two Rate Three Color Marker."; uses metering-stats; } list queueing { description "Statistics for each Queue associated with the Policy."; uses queuing-stats; } } } list metering { description "Statistics for each Meter associated with the Policy."; reference "RFC2697: A Single Rate Three Color Marker RFC2698: A Two Rate Three Color Marker."; uses metering-stats; } list queueing { description "Statistics for each Queue associated with the Policy."; uses queuing-stats; } } action clear { description "Clear statistics action command. Execution of this command should result in all the QoS interface counters to be cleared and set to 0."; input { leaf category { type identityref { base qos-types:clear-counters-type; } description "Category of counters which is being cleared."; } leaf started-at { type yang:date-and-time; description "The date and time when the counters should be cleared."; } } output { leaf finished-at { type yang:date-and-time; description "The date and time when the counters finished clearing."; } } } } } } ]]>

: Figure 9: ietf-qos-oper module

Scheduler Policy Module Scheduling Policy module defines a set of scheduling parameters and associates a Queue Policy with it. file "ietf-scheduler-policy@2026-03-02.yang" module ietf-scheduler-policy { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-scheduler-policy"; prefix scheduler-policy; import ietf-traffic-policy { prefix traffic-policy; } import ietf-qos-action { prefix qos-action; } import ietf-diffserv { prefix diffserv; } import ietf-qos-types { prefix qos-types; reference "RFC XXXX: YANG Models for Quality of Service (QoS)."; } organization "IETF Routing Area Working Group."; contact "WG Web: WG List: Editor: Aseem Choudhary Editor: Mahesh Jethanandani "; description "This module contains a collection of YANG definitions for configuring QoS scheduler policies. Copyright (c) 2023 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 (http://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX; see the RFC itself for full legal notices."; revision 2026-03-02 { description "Initial version."; reference "RFC XXXX: YANG Models for Quality of Service (QoS)."; } augment "/traffic-policy:policies/traffic-policy:policy" + "/traffic-policy:classifier/traffic-policy:inline" + "/traffic-policy:filter" { when "derived-from-or-self(../../../traffic-policy:type, " + "'qos-types:scheduler-policy-type')" { description "This filter can be used only when policy type is scheduler-policy."; } choice filter-params { description "Choice of filter parameters."; case filter-match-all { uses diffserv:filter-match-all; description "A filter that matches all packets."; } } description "Augments Queue Policy Classifier to add filter parameters."; } augment "/traffic-policy:policies/traffic-policy:policy/" + "traffic-policy:classifier/traffic-policy:action" { when "derived-from-or-self(../../traffic-policy:type, " + "'qos-types:scheduler-policy-type')" { description "These actions apply only when policy type is scheduler-policy."; } choice action-params { description "Choice of action parameters that can be taken."; case scheduler { uses qos-action:scheduler; } case queue-policy-name { container queue-policy-name { leaf queue-policy { type leafref { path "/traffic-policy:policies/" + "traffic-policy:policy/traffic-policy:name"; } must "derived-from-or-self(/traffic-policy:policies" + "/traffic-policy:policy/traffic-policy:type," + "'qos-types:queue-policy-type')"; mandatory true; description "This leafref refers to Queue Policy name."; } description "Container for Queue Policy name."; } } } description "Augments Queue Policy Classifier to add in Action parameters for Scheduler policy."; } }

]]>


        
          
          

                  Figure 11: ietf-scheduler-policy module


      
        Queue Policy Module
        
   Queue Policy module augments the Traffic Policy module.  It augments
   to allow queues to be referred to in a policy.  The match is based on
   Traffic Group and action parameters which are defined in QoS Action
   module.
        
   The figure below provides the tree diagram for the ietf-queue-policy
   module.  This module describes the mechanisms used for managing
   congestion.  It includes configurations for queue buffers, scheduling
   algorithms (such as Strict Priority or Weighted Round Robin), and
   drop policies (such as Tail Drop or Weighted Random Early Detection).
   The model supports nested scheduling structures to accommodate
   complex hierarchical QoS requirements.
        
          module: ietf-queue-policy
          
        
        
          ietf-queue-policy abridged tree diagram
          
        
        
     WG List:  

     Editor:   Aseem Choudhary
               
     Editor:   Mahesh Jethanandani
               ";

  description
    "This module contains a collection of YANG definitions for
     QoS Queue policies.

     Copyright (c) 2023 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
     (http://trustee.ietf.org/license-info).

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

  revision 2026-03-02 {
    description
      "Initial version.";
    reference

      "RFC XXXX: YANG Models for Quality of Service (QoS).";
  }

  augment "/traffic-policy:policies/traffic-policy:policy" +
          "/traffic-policy:classifier/traffic-policy:inline" +
          "/traffic-policy:filter" {
    when "derived-from-or-self(../../../traffic-policy:type, " +
         "'qos-types:queue-policy-type')" {
      description
        "If policy type is Queue Policy, this filter can be used.";
    }

    choice filter-params {
      description
        "Choice of Action types.";
      case traffic-group {
        uses diffserv:traffic-group;
        description
          "Traffic group name.";
      }
      case filter-match-all {
        uses diffserv:filter-match-all;
        description
          "When the filter type is set to match all packets.";
      }
    }
    description
      "Augments Queue Policy to add filter types.";
  }

  augment "/traffic-policy:policies/traffic-policy:policy" +
          "/traffic-policy:classifier/traffic-policy:action" {
    when "derived-from-or-self(../../traffic-policy:type,"  +
         "'qos-types:queue-policy-type')" {
      description
        "Queue Policy actions.";
    }

    choice action-params {
      description
        "Choice of different action parameters that can be taken.";

      case queue-template-name {
        uses qos-action:queue-reference;
      }

      case queue-inline {
        uses qos-action:queue;

      }
    }
    description
      "Augments Queue Policy action to add Queue template reference
       or Queue inline.";
  }
}
]]>
        
          
          

                    Figure 13: ietf-queue-policy module
        
      
      
        IETF QoS Types Module
        
   The QoS Types module contains all the type definitions used by the
   other QoS modules.
        
     WG List:  

     Editor:   Aseem Choudhary
               
     Editor:   Mahesh Jethanandani
               ";

  description
    "This module contains type definitions for all QoS types.

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

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

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

  revision 2026-03-02 {
    description
      "Initial version";
    reference
      "RFC XXXX: YANG Models for Quality of Service (QoS).";
  }

  /*
   * Features.
   */
  feature child-policy {
    description
      " This feature allows configuration of hierarchical policy.";
  }
  feature qos-count {
    description
      "This feature allows action configuration to enable
       counter in a classifier";
  }
  feature named-qos-count {
    description
      "This feature allows action configuration to enable
       named counter in a classifier";
  }

  /*
   * Identities.
   */
  identity policy-type {
    description
      "Base identity for policy type.";
  }
  identity diffserv-policy-type {
    base policy-type;
    description
      "Policy type defined as Diffserv.";
  }
  identity ipv4-diffserv-policy-type {
    base policy-type;
    description
      "Policy type defined as a Diffserv IPv4 policy type.";
  }
  identity ipv6-diffserv-policy-type {
    base policy-type;
    description

      "Policy type defined as a Diffserv IPv6 policy type.";
  }
  identity queue-policy-type {
    base policy-type;
    description
      "Policy type defined as a queue policy type.";
  }
  identity scheduler-policy-type {
    base policy-type;
    description
      "Policy type defined as a scheduler policy type.";
  }

  identity action-type {
    description
      "Base identity for the action type.";
  }
  identity dscp-marking {
    base action-type;
    description
      "Action type defined as DSCP marking.";
  }
  identity meter-inline {
    base action-type;
    description
      "Action type defined as meter inline.";
  }
  identity meter-reference {
    base action-type;
    description
      "Action type defined as meter reference.";
  }
  identity queue {
    base action-type;
    description
      "Action type defined as queue.";
  }
  identity scheduler {
    base action-type;
    description
      "Action type defined as scheduler.";
  }
  identity discard {
    base action-type;
    description
      "Action type defined as discard.";
  }
  identity child-policy {

    if-feature child-policy;
    base action-type;
    description
      "Action type defined as child policy.";
  }
  identity qos-count {
    if-feature qos-count;
    base action-type;
    description
      "Action type defined as qos count.";
  }
  identity named-qos-count {
    if-feature named-qos-count;
    base action-type;
    description
      "Action type specified as a named qos counter.";
  }
  identity queue-policy-name {
    base action-type;
    description
      "Action type specified as a queue policy name.";
  }

  identity meter-type {
    description
      "Base identity for types of meter.";
  }
  identity one-rate-two-color {
    base meter-type;
    description
      "Meter type specified as one rate two color meter.";
  }
  identity one-rate-tri-color {
    base meter-type;
    description
      "Meter type specified as one rate three color meter.";
  }
  identity two-rate-tri-color {
    base meter-type;
    description
      "Meter type specified as two rate three color meter.";
  }

  identity drop-type {
    description
      "Base identity for drop algorithm.";
  }
  identity tail-drop {

    base drop-type;
    description
      "Drop algorithm specified as tail drop.";
  }
  identity red {
    base drop-type;
    description
      "Drop algorithm specified as RED.";
  }
  identity wred {
    base drop-type;
    description
      "Drop algorithm specified as WRED.";
  }

  identity rate-unit-type {
    description
      "Base definition for the type of rate unit.";
  }
  identity bits-per-second {
    base rate-unit-type;
    description
      "Rate specified in bits per second.";
  }
  identity percent {
    base rate-unit-type;
    description
      "Rate specified as a percentage of queue depth.";
  }

  identity burst-unit-type {
    description
      "Base definition for burst specification.";
  }
  identity bytes {
    base burst-unit-type;
    description
      "Burst specified in bytes.";
  }
  identity microsecond {
    base burst-unit-type;
    description
      "Burst specified in microseconds.";
  }

  identity red-threshold-unit {
    description
      "Base definition for RED threshold specification.";
  }
  identity red-threshold-bytes {
    base red-threshold-unit;
    description
      "RED threshold specified in bytes.";
  }
  identity red-threshold-us {
    base red-threshold-unit;
    description
      "RED threshold specified in microseconds.";
  }
  identity red-threshold-pc {
    base red-threshold-unit;
    description
      "RED threshold specified as a percentage.";
  }
  identity red-theshold-pt {
    base red-threshold-unit;
    description
      "RED threshold specified per-thousand.";
  }

  identity wred-color-type {
    description
      "Base identity for WRED color type.";
  }
  identity wred-color-dscp {
    base wred-color-type;
    description
      "WRED color specified by DSCP.";
  }

  identity probability-unit {
    description
      "Base definition for probability unit.";
  }
  identity probability-pc {
    base probability-unit;
    description
      "Probability specified in percentage.";
  }
  identity probability-pt {
    base probability-unit;
    description
      "Probability specified in unit of per thousand.";
  }
  identity probability-denominator {
    base probability-unit;

    description
      "Probability value specified as a denominator value
       while numerator is always 1.";
  }

  identity filter-type {
    description
      "Base identity for filter type.";
  }

  identity dscp {
    base filter-type;
    description
      "Filter type specified as DSCP.";
  }
  identity source-ipv4-prefix {
    base filter-type;
    description
      "Filter type specified as source IPv4 prefix.";
  }
  identity destination-ipv4-prefix {
    base filter-type;
    description
      "Filter type specified as destination IPv4 prefix.";
  }
  identity source-ipv6-prefix {
    base filter-type;
    description
      "Filter type specified as source IPv6 prefix.";
  }
  identity destination-ipv6-prefix {
    base filter-type;
    description
      "Filter type specified as destination IPv6 prefix.";
  }
  identity source-port {
    base filter-type;
    description
      "Filter type specified as source port.";
  }
  identity destination-port {
    base filter-type;
    description
      "Filter type specified as destination port.";
  }
  identity protocol {
    base filter-type;
    description

      "Filter type specified as protocol.";
  }
  identity traffic-group-name {
    base filter-type;
    description
      "Filter type specified as traffic group name.";
  }
  identity filter-match-all {
    base filter-type;
    description
      "Filter type specified as match all.";
  }

  typedef match-operation-type {
    type enumeration {
      enum match-all {
        description
          "Classifier entry filters logical AND operation";
      }
      enum match-any {
        description
          "Classifier entry filters logical OR operation";
      }
    }
    default "match-all";
    description
      "Filter match logical operation type";
  }

  identity direction {
    description
      "Base identity for traffic direction";
  }
  identity ingress {
    base direction;
    description
      "Direction of traffic coming into the network entry";
  }
  identity egress {
    base direction;
    description
      "Direction of traffic going out of the network entry";
  }

  identity meter-action-type {
    description
      "Base identify for actions related to metering";
  }

  identity action-drop {
    base meter-action-type;
      description
        "Drop packets that conform/exceed/violate to the set value.";
  }
  identity action-transmit {
    base meter-action-type;
      description
        "Transmit packets that conform/exceed/violate to the set
         value.";
  }
  identity action-mark {
    base meter-action-type;
      description
        "Mark packets that conform/exceed/violate to the set value.";
  }

  identity clear-counters-type {
    description
      "Base identify for clear interface counters related options";
  }
  identity all-counters {
    base clear-counters-type;
      description
        "Clear all counters in both directions.";
  }
  identity inbound-counters {
    base clear-counters-type;
      description
        "Clear counters in inbound direction.";
  }
  identity outbound-counters {
    base clear-counters-type;
      description
        "Clear counters in outbound direction.";
  }
}
]]>
        
          
          

                      Figure 14: ietf-qos-types module


    
      IANA Considerations
      
   This document registers seven URIs and seven YANG modules.
      
        URI Registration
        
   Following the format in the IETF XML registry , the
   following registration is requested to be made:
        
          
          

             URI: urn:ietf:params:xml:ns:yang:ietf-qos-types
             URI: urn:ietf:params:xml:ns:yang:ietf-diffserv
             URI: urn:ietf:params:xml:ns:yang:ietf-qos-action
             URI: urn:ietf:params:xml:ns:yang:ietf-qos-oper
             URI: urn:ietf:params:xml:ns:yang:ietf-queue-policy
             URI: urn:ietf:params:xml:ns:yang:ietf-scheduler-policy
             URI: urn:ietf:params:xml:ns:yang:ietf-traffic-policy
        
        
   Registrant Contact: The IESG.  XML: N/A, the requested URI is an XML
   namespace.
      
      
        YANG Module Name Registration
        
   This document registers seven YANG modules in the YANG Module Names
   registry YANG .
        
      
    
    
      Security Considerations
      
   The YANG module specified in this document defines a schema for data
   that is designed to be accessed via network management protocols such
   as NETCONF  or RESTCONF .  The lowest NETCONF layer
   is the secure transport layer, and the mandatory-to-implement secure
   transport is Secure Shell (SSH) .  The lowest RESTCONF layer
   is HTTPS, and the mandatory-to-implement secure transport is TLS
   .  The NETCONF Access Control Model (NACM) 
   provides the means to restrict access for particular NETCONF or
   RESTCONF users to a preconfigured subset of all available NETCONF or
   RESTCONF protocol operations and content.
      
   There are a number of data nodes defined in this YANG module that are
   writable/creatable/deletable (i.e., config true, which is the
   default).  These data nodes may be considered sensitive or vulnerable
   in some network environments.  Write operations (e.g., edit-config)
   to these data nodes without proper protection can have a negative
   effect on network operations.  Some of the subtrees and data nodes
   and their sensitivity/vulnerability are described here.
      
   - 'filter-operation' and 'filter'. 'filter-operation' includes the
   ability to 'match all', which is a logical AND operation or 'match
   any', which is a logical OR operation.  Both the operations have an
   impact on the traffic that is being classified.  Similarly, the
   'filter' list decides what parts of the packet will examined, which
   will also impact the traffic that is being classified.
      
   - 'action'.  The 'action' decides what action will be taken on the
   packet.  That includes whether the packet will be marked, queued, or
   just discarded.
      
   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.  Some of the subtrees and data
   nodes and their sensitivity/vulnerability are:
      
   - 'conform-pkts', 'conform-bytes', 'exceed-pkts', 'exceed-bytes',
   'voilate-pkts' or 'voilate-bytes'.  All these statistics combined
   with their 'meter-id' are an indication of what is happening in the
   network, and can allow for an intruder insight into how to disrupt
   the traffic.
      
   - 'tail-drop-pkts', 'red-drop-bytes', 'wred-stats' are examples of
   statistics that indicate the kind of traffic that is being profiled
   for drop or marked for Explicit Congestion Notification (ECN), and
   can give an insight into the operation of a network.
      
   Some of the RPC operations in this YANG module may be considered
   sensitive or vulnerable in some network environments.  It is thus
   important to control access to these operations.  These are the
   operations and their sensitivity/vulnerability:
      
   - The model allows for statistics to be cleared by the 'clear' RPC
   operation, causing all the individual statistics to be cleared.
    
    
      Acknowledgement
      
   The authors wish to thank Ruediger Geib, Fred Baker, Greg Mirsky, Tom
   Petch, Acee Lindem, Adrian Farrel, David Black, Jurgen Schonwalder,
   Colin Perkins, Joseph Touch, Zaheduzzaman Sarker many others for
   their helpful comments.
    
    
      Contributors
      
   The following people have substantially contributed to the editing of
   this document:


  
    
      References
      
        Normative References
        
          
            Key words for use in RFCs to Indicate Requirement Levels
            
            
            
              In many standards track documents several words are used to signify the requirements in the specification. These words are often capitalized. This document defines these words as they should be interpreted in IETF documents. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements.
            
          
          
          
          
        
        
          
            Common YANG Data Types
            
            
            
              This document defines a collection of common data types to be used with the YANG data modeling language. It includes several new type definitions and obsoletes RFC 6991.
            
          
          
          
        
        
          
            YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)
            
            
            
              YANG is a data modeling language used to model configuration and state data manipulated by the Network Configuration Protocol (NETCONF), NETCONF remote procedure calls, and NETCONF notifications. [STANDARDS-TRACK]
            
          
          
          
        
        
          
            The YANG 1.1 Data Modeling Language
            
            
            
              YANG is a data modeling language used to model configuration data, state data, Remote Procedure Calls, and notifications for network management protocols. This document describes the syntax and semantics of version 1.1 of the YANG language. YANG version 1.1 is a maintenance release of the YANG language, addressing ambiguities and defects in the original specification. There are a small number of backward incompatibilities from YANG version 1. This document also specifies the YANG mappings to the Network Configuration Protocol (NETCONF).
            
          
          
          
        
        
          
            Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words
            
            
            
              RFC 2119 specifies common key words that may be used in protocol specifications. This document aims to reduce the ambiguity by clarifying that only UPPERCASE usage of the key words have the defined special meanings.
            
          
          
          
          
        
        
          
            Network Management Datastore Architecture (NMDA)
            
            
            
            
            
            
            
              Datastores are a fundamental concept binding the data models written in the YANG data modeling language to network management protocols such as the Network Configuration Protocol (NETCONF) and RESTCONF. This document defines an architectural framework for datastores based on the experience gained with the initial simpler model, addressing requirements that were not well supported in the initial model. This document updates RFC 7950.
            
          
          
          
        
        
          
            A YANG Data Model for Interface Management
            
            
            
              This document defines a YANG data model for the management of network interfaces. It is expected that interface-type-specific data models augment the generic interfaces data model defined in this document. The data model includes definitions for configuration and system state (status information and counters for the collection of statistics).
              The YANG data model in this document conforms to the Network Management Datastore Architecture (NMDA) defined in RFC 8342.
              This document obsoletes RFC 7223.
            
          
          
          
        
        
          
            Update to IANA Registration Procedures for Pool 3 Values in the Differentiated Services Field Codepoints (DSCP) Registry
            
            
            
              The Differentiated Services (Diffserv) architecture specifies use of the DS field in the IPv4 and IPv6 packet headers to carry one of 64 distinct differentiated services field codepoint (DSCP) values. The Internet Assigned Numbers Authority (IANA) maintains a registry of assigned DSCP values.
              This update to RFC 2474 changes the IANA registration policy for Pool 3 of the registry (i.e., DSCP values of the form xxxx01) to Standards Action, i.e., values are assigned through a Standards Track or Best Current Practice RFC. The update also removes permission for experimental and local use of the codepoints that form Pool 3 of the DSCP registry; Pool 2 Codepoints (i.e., DSCP values of the form xxxx11) remain available for these purposes.
            
          
          
          
        
      
      
        Informative References
        
          
            Definition of the Differentiated Services Field (DS Field) in the IPv4 and IPv6 Headers
            
            
            
            
            
            
              This document defines the IP header field, called the DS (for differentiated services) field. [STANDARDS-TRACK]
            
          
          
          
        
        
          
            An Architecture for Differentiated Services
            
            
            
            
            
            
            
            
              This document defines an architecture for implementing scalable service differentiation in the Internet. This memo provides information for the Internet community.
            
          
          
          
        
        
          
            A Single Rate Three Color Marker
            
            
            
            
              This document defines a Single Rate Three Color Marker (srTCM), which can be used as component in a Diffserv traffic conditioner. This memo provides information for the Internet community.
            
          
          
          
        
        
          
            A Two Rate Three Color Marker
            
            
            
            
              This document defines a Two Rate Three Color Marker (trTCM), which can be used as a component in a Diffserv traffic conditioner. This memo provides information for the Internet community.
            
          
          
          
        
        
          
            The IETF XML Registry
            
            
            
              This document describes an IANA maintained registry for IETF standards which use Extensible Markup Language (XML) related items such as Namespaces, Document Type Declarations (DTDs), Schemas, and Resource Description Framework (RDF) Schemas.
            
          
          
          
          
        
        
          
            Network Configuration Protocol (NETCONF)
            
            
            
            
            
            
              The Network Configuration Protocol (NETCONF) defined in this document provides mechanisms to install, manipulate, and delete the configuration of network devices. It uses an Extensible Markup Language (XML)-based data encoding for the configuration data as well as the protocol messages. The NETCONF protocol operations are realized as remote procedure calls (RPCs). This document obsoletes RFC 4741. [STANDARDS-TRACK]
            
          
          
          
        
        
          
            Using the NETCONF Protocol over Secure Shell (SSH)
            
            
            
              This document describes a method for invoking and running the Network Configuration Protocol (NETCONF) within a Secure Shell (SSH) session as an SSH subsystem. This document obsoletes RFC 4742. [STANDARDS-TRACK]
            
          
          
          
        
        
          
            RESTCONF Protocol
            
            
            
            
            
              This document describes an HTTP-based protocol that provides a programmatic interface for accessing data defined in YANG, using the datastore concepts defined in the Network Configuration Protocol (NETCONF).
            
          
          
          
        
        
          
            YANG Tree Diagrams
            
            
            
            
              This document captures the current syntax used in YANG module tree diagrams. The purpose of this document is to provide a single location for this definition. This syntax may be updated from time to time based on the evolution of the YANG language.
            
          
          
          
          
        
        
          
            Network Configuration Access Control Model
            
            
            
            
              The standardization of network configuration interfaces for use with the Network Configuration Protocol (NETCONF) or the RESTCONF protocol requires a structured and secure operating environment that promotes human usability and multi-vendor interoperability. There is a need for standard mechanisms to restrict NETCONF or RESTCONF protocol access for particular users to a preconfigured subset of all available NETCONF or RESTCONF protocol operations and content. This document defines such an access control model.
              This document obsoletes RFC 6536.
            
          
          
          
          
        
        
          
            The Transport Layer Security (TLS) Protocol Version 1.3
            
            
            
              This document specifies version 1.3 of the Transport Layer Security (TLS) protocol. TLS allows client/server applications to communicate over the Internet in a way that is designed to prevent eavesdropping, tampering, and message forgery.
              This document updates RFCs 5705 and 6066, and obsoletes RFCs 5077, 5246, and 6961. This document also specifies new requirements for TLS 1.2 implementations.
            
          
          
          
        
      
    
    
      Complete tree Diagrams
      
   This section carries complete tree diagrams of each module defined in
   this draft.  The tree diagrams use the notation defined in YANG Tree
   Diagrams .
      
        Traffic Policy Module Tree Diagram
        
          Traffic Policy Tree Diagram
           /policies/policy/name
]]>
        
      
      
        QoS Action Module Tree Diagram
        
      
      
        Diffserv Module Tree Diagram
        
          module: ietf-diffserv
          
        
        
          Diffserv Module Tree Diagram
           /qos-action:meters/meter/name
       |     +--rw type    identityref
       +--:(traffic-group-marking)
       |  +--rw traffic-group
       |     +--rw traffic-group?   string
       +--:(child-policy) {qos-types:child-policy}?
       |  +--rw child-policy {qos-types:child-policy}?
       |     +--rw name?   string
       +--:(qos-count) {qos-types:qos-count}?
       |  +--rw qos-count {qos-types:qos-count}?
       |     +--rw qos-count-action?   empty
       +--:(named-qos-count) {qos-types:named-qos-count}?
       |  +--rw named-qos-count {qos-types:named-qos-count}?
       |     +--rw name?   string

       +--:(queue-inline)
       |  +--rw queue
       |     +--rw priority
       |     |  +--rw level?   uint8
       |     +--rw min-rate
       |     |  +--rw value?   uint64
       |     |  +--rw unit?    identityref
       |     +--rw max-rate
       |     |  +--rw value?         uint64
       |     |  +--rw unit?          identityref
       |     |  +--rw burst-value?   uint64
       |     |  +--rw burst-unit?    identityref
       |     +--rw algorithmic-drop
       |        +--rw (drop-algorithm)?
       |           +--:(tail-drop)
       |           |  +--rw tail-drop
       |           |     +--rw tail-drop?   empty
       |           +--:(red)
       |           |  +--rw red
       |           |     +--rw min-threshold-val?      uint64
       |           |     +--rw min-threshold-unit?     identityref
       |           |     +--rw max-threshold-val?      uint64
       |           |     +--rw max-threshold-unit?     identityref
       |           |     +--rw weight?                 uint8
       |           |     +--rw max-probability-val?    uint64
       |           |     +--rw max-probability-unit?   identityref
       |           |     +--rw ecn-enabled?            boolean
       |           +--:(wred)
       |           |  +--rw wred
       |           |     +--rw wred* [profile]
       |           |     |  +--rw profile                 uint8
       |           |     |  +--rw color-type?             identityref
       |           |     |  +--rw color-val* [min max]
       |           |     |  |  +--rw min    uint8
       |           |     |  |  +--rw max    uint8
       |           |     |  +--rw min-threshold-val?      uint64
       |           |     |  +--rw min-threshold-unit?     identityref
       |           |     |  +--rw max-threshold-val?      uint64
       |           |     |  +--rw max-threshold-unit?     identityref
       |           |     |  +--rw weight?                 uint8
       |           |     |  +--rw max-probability-val?    uint64
       |           |     |  +--rw max-probability-unit?   identityref
       |           |     +--rw ecn-enabled?   boolean
       |           +--:(codel)
       |           |  +--rw codel
       |           |     +--rw target?        uint64
       |           |     +--rw interval?      uint64
       |           |     +--rw ecn-enabled?   boolean
       |           +--:(fq-codel)
       |              +--rw fq-codel
       |                 +--rw target?        uint64
       |                 +--rw interval?      uint64
       |                 +--rw flows?         uint64
       |                 +--rw ecn-enabled?   boolean
       +--:(scheduler-inline)
          +--rw scheduler
             +--rw min-rate
             |  +--rw value?   uint64
             |  +--rw unit?    identityref
             +--rw max-rate
                +--rw value?         uint64
                +--rw unit?          identityref
                +--rw burst-value?   uint64
                +--rw burst-unit?    identityref
]]>
        
      
      
        QoS Operational Module Tree Diagram
        
          module: ietf-qos-oper
          
        
        
          QoS Operational Module Tree Diagram
          
        
      
      
        Scheduler Policy Module Tree Diagram
        
          module: ietf-scheduler-policy
          
        
        
          Scheduler Policy Module Tree Diagram
           /traffic-policy:policies/policy/name
]]>
        
      
      
        Queue Policy Module Tree Diagram
        
          module: ietf-queue-policy
          
        
        
          Queue Policy Module Tree Diagram
           /qos-action:queues/queue/name
       +--:(queue-inline)
          +--rw queue
             +--rw priority
             |  +--rw level?   uint8
             +--rw min-rate
             |  +--rw value?   uint64
             |  +--rw unit?    identityref
             +--rw max-rate
             |  +--rw value?         uint64
             |  +--rw unit?          identityref
             |  +--rw burst-value?   uint64
             |  +--rw burst-unit?    identityref
             +--rw algorithmic-drop
                +--rw (drop-algorithm)?
                   +--:(tail-drop)
                   |  +--rw tail-drop
                   |     +--rw tail-drop?   empty
                   +--:(red)
                   |  +--rw red
                   |     +--rw min-threshold-val?      uint64
                   |     +--rw min-threshold-unit?     identityref
                   |     +--rw max-threshold-val?      uint64
                   |     +--rw max-threshold-unit?     identityref
                   |     +--rw weight?                 uint8
                   |     +--rw max-probability-val?    uint64
                   |     +--rw max-probability-unit?   identityref
                   |     +--rw ecn-enabled?            boolean
                   +--:(wred)
                   |  +--rw wred
                   |     +--rw wred* [profile]

                   |     |  +--rw profile                 uint8
                   |     |  +--rw color-type?             identityref
                   |     |  +--rw color-val* [min max]
                   |     |  |  +--rw min    uint8
                   |     |  |  +--rw max    uint8
                   |     |  +--rw min-threshold-val?      uint64
                   |     |  +--rw min-threshold-unit?     identityref
                   |     |  +--rw max-threshold-val?      uint64
                   |     |  +--rw max-threshold-unit?     identityref
                   |     |  +--rw weight?                 uint8
                   |     |  +--rw max-probability-val?    uint64
                   |     |  +--rw max-probability-unit?   identityref
                   |     +--rw ecn-enabled?   boolean
                   +--:(codel)
                   |  +--rw codel
                   |     +--rw target?        uint64
                   |     +--rw interval?      uint64
                   |     +--rw ecn-enabled?   boolean
                   +--:(fq-codel)
                      +--rw fq-codel
                         +--rw target?        uint64
                         +--rw interval?      uint64
                         +--rw flows?         uint64
                         +--rw ecn-enabled?   boolean
]]>
        
      
    
    
      Company A and Company B examples
      
   Company A and Company B Diffserv modules augments all the filter
   types of the QoS Classifier module as well as the QoS Policy module
   that allow it to define marking, metering, min-rate, max-rate
   actions.  Queueing and metering counters are realized by augmenting
   of the QoS Target module.
      
        Example of Company A Diffserv Model
        
   The following Company A vendor example augments the QoS and Diffserv
   model, demonstrating some of the following functionality:
        
          
            use of template based classifier definitions
          
        
        
   - use of single policy type modelling queue, scheduler policy, and a
   filter policy.  All of these policies either augment the QoS policy
   or the Diffserv modules
         file "example-compa-diffserv@2026-03-02.yang"
module example-compa-diffserv {
  yang-version 1.1;
  namespace "urn:ietf:params:xml:ns:yang:example-compa-diffserv";
  prefix example;

  import ietf-qos-types {
    prefix qos-types;
    reference
      "RFC XXXX: YANG Models for Quality of Service (QoS).";
  }
  import ietf-traffic-policy {
    prefix traffic-policy;
    reference
      "RFC XXXX: YANG Models for Quality of Service (QoS).";
  }
  import ietf-qos-action {
    prefix qos-action;
    reference
      "RFC XXXX: YANG Models for Quality of Service (QoS).";
  }
  import ietf-diffserv {
    prefix diffserv;
    reference
      "RFC XXXX: YANG Models for Quality of Service (QoS).";
  }
  organization "Company A";
  contact
    "Editor:   XYZ
              ";
  description
    "This module contains a collection of YANG definitions of
     companyA diffserv specification extension.";
  revision 2026-03-02 {
    description
      "Initial revision for diffserv actions on network packets.";
    reference
      "RFC XXXX: A YANG Data Model for Quality of Service (QoS).";
  }

  identity default-policy-type {
    base qos-types:policy-type;
    description
      "This defines default policy-type.";
  }

  identity qos-group {
    base qos-types:filter-type;
    description
      "Filter-type to match on  packet metadata. This metadata
       can be used for packet marking, queuing for traffic in
       egress direction.";
  }

  grouping qos-group {
    list qos-group {
      key "min max";
      description
        "List of qos-groups to match on. A QoS group is a set of
         packets tagged as group.";
      leaf min {
        type uint8;
        description
          "Minimum value of qos-group range.";
      }
      leaf max {
        type uint8;
        must ". >= ../min" {
          error-message
          "The qos-group max must be
           greater than or equal to qos-group min.";
        }
        description
          "Maximum value of qos-group range.";
      }
    }
    description
      "Filter containing list of qos-group ranges.";
  }
  grouping bw-remaining-percent {
    container bw-remaining-percent {
      leaf value {
        type uint8;
        units "percentage";
        description
          "Percentage of the remaining bandwidth present.";
      }
      description
        "Remaining bandwidth of the link in percent.";
    }
    description
      "Grouping for bandwidth remaining after
      reserved and priority bandwidth.";
  }

  grouping qos-group-marking {
    container qos-group {
      leaf qos-group {
        type uint8;
        description
          "Mark metadata information in the network packet";
      }
      description
        "Container for QoS-Group marking.";
    }
    description
      "Grouping for QoS-Group marking.";
  }

  augment "/traffic-policy:classifiers/" +
    "traffic-policy:classifier/" +
    "traffic-policy:filter/diffserv:filter-param" {
    case qos-group {
      uses qos-group;
      description
        "Filter containing list of qos-group ranges.
        QoS-group represent packet metadata information
        in a network packet.";
    }
    description
      "Augmentation of classifier filters.";
  }

  augment "/traffic-policy:policies/traffic-policy:policy/" +
    "traffic-policy:classifier/" +
    "traffic-policy:action" {
    choice action-params {
      case priority {
        uses qos-action:priority;
      }
      case min-rate {
        uses qos-action:min-rate;
      }
      case max-rate {
        uses qos-action:max-rate;
      }
      case bw-remaining {
        uses bw-remaining-percent;
      }
      case mark-qos-group {
        uses qos-group-marking;
      }
      description

        "Choice of action parameters.";
    }
    description
      "Augments policy entry to add action parameters.";
  }

  augment "/traffic-policy:policies" +
    "/traffic-policy:policy" +
    "/traffic-policy:classifier" +
    "/traffic-policy:action" +
    "/diffserv:action-params" +
    "/diffserv:meter-inline" +
    "/diffserv:meter-types" +
    "/diffserv:single-rate-two-color-meter-type" +
    "/diffserv:single-rate-two-color-meter" {
    description
      "Augment the single-rate-two-color meter to add" +
      "color classifiers.";
    container conform-color {
      uses traffic-policy:generic-classifier-attr;
      description
        "Conform color classifier container.";
    }
    container exceed-color {
      uses traffic-policy:generic-classifier-attr;
      description
        "Exceed color classifier container.";
    }
  }

  augment "/traffic-policy:policies" +
    "/traffic-policy:policy" +
    "/traffic-policy:classifier" +
    "/traffic-policy:action" +
    "/diffserv:action-params" +
    "/diffserv:meter-inline" +
    "/diffserv:meter-types" +
    "/diffserv:single-rate-three-color-meter-type" +
    "/diffserv:single-rate-three-color-meter" {
    description
      "Augment the one-rate-tri-color meter to add" +
      "color classifiers.";
    container conform-color {
      uses traffic-policy:generic-classifier-attr;
      description
        "Conform color classifier container.";
    }
    container exceed-color {

      uses traffic-policy:generic-classifier-attr;
      description
        "Exceed color classifier container.";
    }
    container violate-color {
      uses traffic-policy:generic-classifier-attr;
      description
        "Violate color classifier container.";
    }
  }

  augment "/traffic-policy:policies" +
    "/traffic-policy:policy" +
    "/traffic-policy:classifier" +
    "/traffic-policy:action" +
    "/diffserv:action-params" +
    "/diffserv:meter-inline" +
    "/diffserv:meter-types" +
    "/diffserv:two-rate-three-color-meter-type" +
    "/diffserv:two-rate-three-color-meter" {
    description
      "Augment the two-rate-tri-color meter to add" +
      "color classifiers.";
    container conform-color {
      uses traffic-policy:generic-classifier-attr;
      description
        "Conform color classifier container.";
    }
    container exceed-color {
      uses traffic-policy:generic-classifier-attr;
      description
        "Exceed color classifier container.";
    }
    container violate-color {
      uses traffic-policy:generic-classifier-attr;
      description
        "Violate color classifier container.";
    }
  }
}

]]>
      

      
        Example of Company B Diffserv Model
        
   The following vendor example augments the QoS and Diffserv model,
   demonstrating some of the following functionality:
        
   - use of inline classifier definitions (defined inline in the policy
   vs referencing an externally defined classifier)
        
   - use of mulitple policy types, e.g. a queue policy, a scheduler
   policy, and a filter policy.  All of these policies either augment
   the QoS policy or the Diffserv modules
        
   - use of a queue module, which uses and extends the queue grouping
   from the QoS Action module
        
  file "example-compb-diffserv-filter-policy@2026-03-02.yang"
module example-compb-diffserv-filter-policy {
  yang-version 1.1;
  namespace "urn:ietf:params:xml:ns:yang:" +
            "example-compb-diffserv-filter-policy";
  prefix compb-filter-policy;

  import ietf-qos-types {
    prefix qos-types;
    reference
      "RFC XXXX: YANG Models for Quality of Service (QoS).";
  }
  import ietf-traffic-policy {
    prefix traffic-policy;
  }
  import ietf-qos-action {
    prefix qos-action;
  }
  import ietf-diffserv {
    prefix diffserv;
  }

  organization
    "Company B";

  contact
    "Editor:   XYZ
               ";

  description
    "This module contains a collection of YANG definitions for
     configuring diffserv specification implementations.

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

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

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

  revision 2026-03-02 {
    description
      "Initial revision of diffserv policy for Company B.";
    reference
      "RFC XXXX: YANG Data Model for QoS.";
  }

  /*************************************************
   * Classification types
   *************************************************/

  identity internal-loss-priority  {
     base qos-types:filter-type;
     description
        "Internal loss priority filter type.";
  }

  grouping loss-priority {
    list loss-priority {
      key "loss-priority";
      description
        "list of loss-priorities";
      leaf loss-priority {
        type enumeration {
          enum high {
           description "High loss Priority.";
          }
          enum medium-high {
           description "Medium to high loss priority.";
          }
          enum medium-low {
           description "Medium to low loss priority.";
          }
          enum low {

           description "Low loss priority.";
          }
        }
        description
          "Loss priority.";
      }
    }
    description
      "Filter containing list of loss priorities";
  }

  augment "/traffic-policy:policies" +
          "/traffic-policy:policy" +
          "/traffic-policy:classifier" +
          "/traffic-policy:inline/traffic-policy:filter" +
          "/diffserv:filter-params" {
    case internal-loss-priority {
        uses loss-priority;
      description
        "Filter Type Internal-loss-priority";
    }
    description
      "Augments Diffserv Classifier with vendor " +
      "specific types.";
  }

  /*************************************************
   * Actions
   *************************************************/

  identity mark-loss-priority {
    base qos-types:action-type;
    description
      "Mark loss-priority action type.";
  }

  grouping mark-loss-priority {
    container mark-loss-priority {
      leaf loss-priority {
        type enumeration {
          enum high {
           description "High loss Priority.";
          }
          enum medium-high {
           description "Medium to high loss priority.";
          }
          enum medium-low {
           description "Medium to low loss priority.";
          }
          enum low {
           description "Low loss priority.";
          }
        }
        description
          "Loss priority.";
      }
      description
        "Mark loss priority container.";
    }
    description
      "Mark loss priority grouping.";
  }

  augment "/traffic-policy:policies" +
          "/traffic-policy:policy" +
          "/traffic-policy:classifier" +
          "/traffic-policy:action" +
          "/diffserv:action-params" {
    case traffic-group-marking {
      uses qos-action:traffic-group-marking;
      description
        "Mark traffic group in the packet.";
    }
    case mark-loss-priority {
        uses mark-loss-priority;
      description
        "Mark loss priority in the packet.";
    }
    case meter-reference {
        uses qos-action:meter-reference;
      description
        "Assign a meter as an action.";
    }
    case discard {
        uses qos-action:discard;
      description
        "Discard action.";
    }
    case qos-count {
        uses qos-action:qos-count;
      description
        "Traffic-count action - explicit qos-count configuration.";
    }

    description
      "Augments common diffserv policy actions";
  }

  augment "/qos-action:meters" +
          "/qos-action:meter" +
          "/qos-action:meter-types" +
          "/qos-action:single-rate-three-color-meter-type" +
          "/qos-action:single-rate-three-color-meter" {
     leaf one-rate-color-aware {
      type boolean;
      description
        "This defines if the meter is color-aware.";
    }
    description
      "Augmentation of color-aware flag.";
  }
  augment "/qos-action:meters" +
          "/qos-action:meter" +
          "/qos-action:meter-types" +
          "/qos-action:two-rate-three-color-meter-type" +
          "/qos-action:two-rate-three-color-meter" {
     leaf two-rate-color-aware {
      type boolean;
      description
        "This defines if the meter is color-aware.";
    }
    description
      "Augmentation of color-aware flag.";
  }

}

]]>
      

    

    
      Configuration examples
      
   This section describes several examples of how the models defined in
   this draft can be used for configuration.
      
        Configuration example for QoS Classifier
        


  
    my-classifier
    match-all
    
      qt:dscp
      true
      
        11
        13
      
    
    
      qt:source-port
      false
        
          10000
          10300
        
        
          17540
          19800
        
    
  


         Figure 21: Configuration example for QoS Classifier
]]>
      
      
        Configuration example for QoS Policy
        
          <!--
          
	This example shows a QoS policy configuration.
	
          -->
          
        
        
          Configuration example for QoS Policy
          

  
    my-policy
    qt:diffserv-policy-type
    
      my-classifier
      
        
              qt:dscp
              false
            
              21
              22
            
        
      
      
        qt:dscp-marking
        
          23
        
      
    
  

]]>
        
      
      
        Configuration example for QoS Policing