Modular QoS Configuration Guide for Cisco 8000 Series Routers, Cisco IOS XR Release

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Modular QoS Configuration Guide for Cisco 8000 Series Routers, Cisco IOS XR Release

Elements and supported actions of a traffic policy

Updated: June 9, 2026

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Outlines the structure and components of a traffic policy, including class associations, order of evaluation, and supported QoS actions. It details valid combinations of marking, policing, and shaping actions based on traffic direction to ensure correct policy configuration.

Traffic policies define the QoS actions for traffic that matches one or more classes. These policies enforce how classified traffic is marked, shaped, policed, or prioritized on a router.

Elements of a traffic policy

A traffic policy contains these elements:

Name: Identifies the traffic policy. The name is referenced when you apply the policy to an interface.
Traffic class association: Specifies one or more traffic classes (defined using class-map) to include in the policy. The Modular QoS CLI (MQC) allows multiple traffic classes within a single policy.
QoS actions: Defines the actions to be applied to each traffic class. Supported actions include marking, policing, shaping, prioritizing, and queuing traffic.

Order of traffic class entries in a policy map

The order of class entries in a policy map determines how hardware evaluates the match rules.

Class match rules are programmed into the TCAM in the order specified in the policy map.
If a packet matches multiple classes, only the first matching class is used and only its configured actions are applied.

Number of classes per policy map

You can configure:

up to 8 traffic classes per ingress policy map, and
up to 8 traffic classes per egress policy map.

Starting from Cisco IOS XR Release 26.2.1, we support up to 16 class maps per egress QoS policy map, increased from the previous limit of 8 class maps. For more information on the supported platforms, refer to the feature history table under Packet classification.

Supported QoS actions in a traffic policy map

In the MQC, you apply specific QoS actions in a policy-map after classifying traffic via class-map.

The table

outlines the supported actions
specifies the direction (ingress or egress) in which each action can be applied and,
helps prevent configuration errors by guiding you to apply only valid combinations.

Table 1. QoS actions supported in policy maps
QoS action	Direction	Notes
bandwidth remaining	Egress	Configures remaining bandwidth allocation for a class.
mark	Ingress and egress	See Packet Marking for marking options.
police	Ingress	Applies a traffic policing action.
priority	Egress	Supports priority levels 1 to 7.
queue-limit	Egress	Sets a threshold for queue depth.
shape	Egress	Configures traffic shaping per class.
red	Egress	Enables Random Early Detection (RED). Supports discard-class values: 0—typically associated with default or lower-priority discard behavior. 1—often used for slightly higher-priority traffic, still eligible for drop under congestion.

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