Cisco IOS XR Modular Quality of Service Configuration Guide for the Cisco XR 12000 Series Router, Release 4.3.x
Configuring Fabric QoS Policies and Classes
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Configuring Fabric QoS Policies and Classes

Configuring Fabric QoS Policies and Classes

This module provides the conceptual and configuration information for fabric QoS.

Feature History for Configuring Fabric Quality of Service Policies and Classes on Cisco IOS XR Software

Release

Modification

Release 3.3.0

The Fabric QoS Policies and Classes feature was introduced.

Prerequisites for Configuring Fabric Quality of Service Policies and Classes

This prerequisite is required for configuring modular fabric QoS on your network:

  • You must be in a user group associated with a task group that includes the proper task IDs. The command reference guides include the task IDs required for each command. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Information About Configuring Fabric Quality of Service Policies and Classes

Overview

The fabricq queue selection mechanism is known as Fabric QoS. To provide class of service to the traffic under fabric congestion scenarios, configure Fabric QoS. The platform-independent user interface allows you to configure an MQC policy on the switch fabric queues. This policy is global for all line cards on the router.

A maximum of six classes can be specified within the fabric QoS policy. Only one class can have priority. Each class has 16 queues. The only applicable actions that can be assigned to a class are:

  • priority
  • bandwidth remaining percent

Fabric QoS policy class maps are restricted to matching a subset of the following classification options:

  • precedence ipv4
  • mpls experimental

Ingress Policy and Fabric QoS Policy Interaction

Be careful when applying ingress QoS policies when they must interact with a fabric QoS policy. Fabric QoS classification is independent of ingress QoS classification. The fabric QoS policy overrides any traffic classification conducted by the ingress policy when determining which traffic should be placed into which fabric QoS queue.

Fabric QoS is constrained to a subset of the possible match criteria that can be used in its class maps. This approach enables multiple ingress QoS policies to interact in the expected manner with a fabric QoS policy.

How to Configure Fabric Quality of Service Policies and Classes

Creating a Traffic Class

See the “Creating a Traffic Class” section in the “Configuring Modular Quality of Service Packet Classification on Cisco IOS XR Software” module.

Creating a Fabric QoS Service Policy

This configuration task explains how to configure a fabric QoS policy.

Restrictions:

  • A maximum of six classes can be specified within the fabric QoS policy.
  • Only one class can have priority.
  • The only applicable actions that can be assigned to a class are:
    • priority
    • bandwidth remaining percent
  • Fabric QoS policy class maps are restricted to matching a subset of these classification options:
    • precedence ipv4
    • mpls experimental
SUMMARY STEPS

    1.    configure

    2.    class-map class-map-name

    3.    match precedence ipv4 precedence value

    4.    policy-map policy-name

    5.    class class-name

    6.    priority[level priority-level ]

    7.    exit

    8.    exit

    9.    switch-fabric service-policy policy_name

    10.    Use the commit or end command.


DETAILED STEPS
     Command or ActionPurpose
    Step 1 configure


    Example:
    RP/0/0/CPU0:router# configure
     

    Enters global configuration mode.

     
    Step 2class-map class-map-name


    Example:
    
    RP/0/0/CPU0:router(config)# class-map class201
    
     

    Creates a class map to be used for matching packets to the class whose name you specify and enters the class map configuration mode. If you specify match-any, one of the match criteria must be met for traffic entering the traffic class to be classified as part of the traffic class. This is the default.

     
    Step 3match precedence ipv4 precedence value


    Example:
    
    RP/0/0/CPU0:router(config-cmap)# match precedence ipv4 5
    
     

    Specifies a precedence value that is used as the match criteria against which packets are checked to determine if they belong to the class specified by the class map. Fabric QoS is supported for IPv4 only.

     
    Step 4policy-map policy-name


    Example:
    
    RP/0/0/CPU0:router(config-cmap)# policy-map policy1
    
     

    Creates or modifies a policy map that can be attached to one or more interfaces to specify a service policy and enters the policy map configuration mode.

     
    Step 5class class-name


    Example:
    
    RP/0/0/CPU0:router(config-pmap)# class class1
    
     

    Specifies the name of the class whose policy you want to create or change.

     
    Step 6priority[level priority-level ]


    Example:
    
    RP/0/0/CPU0:router(config-pmap-c)# priority level 1
    
     

    Specifies priority to a class of traffic belonging to a policy map.

     
    Step 7exit


    Example:
    
    RP/0/0/CPU0:router(config-pmap-c)# exit
    
     

    Returns the router to policy map configuration mode.

     
    Step 8exit


    Example:
    
    RP/0/0/CPU0:router(config-pmap)# exit
    
     

    Returns the router to global configuration mode.

     
    Step 9switch-fabric service-policy policy_name


    Example:
    RP/0/0/CPU0:router(config-pmap-c)# switch-fabric service-policy policy1
    
     

    Configures a service policy for the switch fabric.

     
    Step 10 Use the commit or end command.  

    commit—Saves the configuration changes and remains within the configuration session.

    end—Prompts user to take one of these actions:
    • Yes— Saves configuration changes and exits the configuration session.
    • No—Exits the configuration session without committing the configuration changes.
    • Cancel—Remains in the configuration mode, without committing the configuration changes.
     

    Configuration Examples for Configuring Fabric Quality of Service Policies and Classes

    Configuring Fabric Quality of Service Policies and Classes: Example

    This example shows a fabric QoS configuration:

    
    class-map match-any fab_1
    match precedence ipv4 priority
    
    class-map match-any fab_2
    match precedence ipv4 immediate
    
    class-map match-any fab_3
    match precedence ipv4 flash
    
    class-map match-any fab_4
    match precedence ipv4 flash-override
    
    class-map match-any fab_5
    match precedence ipv4 critical
    
    class-map match-any fab_6
    match precedence ipv4 internet
    
    policy-map fab
    class fab_1
    bandwidth remaining percent 5
    !
    class fab_2
    bandwidth remaining percent 25
    !
    class fab_3
    bandwidth remaining percent 30
    !
    class fab_4
    bandwidth remaining percent 20
    !
    class fab_5
    bandwidth remaining percent 20
    !
    class fab_6
    priority
    !
    
    switch-fabric service-policy fab
    commit
    

    Additional References

    These sections provide references related to implementing fabric QoS policies and classes.

    Related Documents

    Related Topic

    Document Title

    Initial system bootup and configuration

    Cisco IOS XR Getting Started Guide for the Cisco XR 120000 

    Series Router

    Master command reference

    Cisco XR 12000 Series Router Master Command Listing

    QoS commands

    Cisco IOS XR Modular Quality of Service Command Reference for the Cisco XR 12000 Series Router

    User groups and task IDs

    “Configuring AAA Services on Cisco IOS XR Software” module of Cisco IOS XR System Security Configuration Guide

    Standards

    Standards

    Title

    No new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature.

    MIBs

    MIBs

    MIBs Link

    To locate and download MIBs using Cisco IOS XR software, use the Cisco MIB Locator found at the following URL and choose a platform under the Cisco Access Products menu: http:/​/​cisco.com/​public/​sw-center/​netmgmt/​cmtk/​mibs.shtml

    RFCs

    RFCs

    Title

    No new or modified RFCs are supported by this feature, and support for existing RFCs has not been modified by this feature.

    Technical Assistance

    Description

    Link

    The Cisco Technical Support website contains thousands of pages of searchable technical content, including links to products, technologies, solutions, technical tips, and tools. Registered Cisco.com users can log in from this page to access even more content.

    http:/​/​www.cisco.com/​cisco/​web/​support/​index.html