27 Quality of Service

CLI - This example creates a class map call “rd-class,” and sets it to match packets marked for DSCP service value 3.

Console(config)#class-map rd_class

match-any

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Console(config-cmap)#match ip dscp

3

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Console(config-cmap)#

 

 

 

 

 

Creating QoS Policies

This function creates a policy map that can be attached to multiple interfaces.

Command Usage

To configure a Policy Map, follow these steps:

-Create a Class Map as described on page 27-2.

-Open the Policy Map page, and click Add Policy.

-When the Policy Configuration page opens, fill in the “Policy Name” field, and click Add.

-When the Policy Rule Settings page opens, select a class name from the scroll-down list (Class Name field). Configure a policy for traffic that matches criteria defined in this class by setting the quality of service that an IP packet will receive (in the Action field), defining the maximum throughput and burst rate (in the Meter field), and the action that results from a policy violation (in the Exceed field). Then finally click Add to register the new policy.

A policy map can contain multiple class statements that can be applied to the same interface with the Service Policy Settings (page 27-7). You can configure up to 64 policers (i.e., meters or class maps) for each of the following access list types:

MAC ACL, IP ACL (including Standard ACL and Extended ACL), IPv6 Standard ACL, and IPv6 Extended ACL. This limitation applies to each switch chip (ES4524D: ports 1-24, ES4548D: ports 1-24, ports 25-48). Also, note that the maximum number of classes that can be applied to a policy map is 16.

Policing is based on a token bucket, where bucket depth (i.e., the maximum burst before the bucket overflows) is by specified the “Burst” field, and the average rate tokens are removed from the bucket is by specified by the “Rate” option.

After using the policy map to define packet classification, service tagging, and bandwidth policing, it must be assigned to a specific interface by a service policy (page 27-7)to take effect.

Command Attributes

Policy Map

Modify Name and Description – Configures the name and a brief description of a policy map. (Range: 1-16 characters for the name; 1-64 characters for the description)

Edit Classes – Opens the “Policy Rule Settings” page for the selected class entry. Modify the criteria used to service ingress traffic on this page.

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Accton Technology 24/48-Port, ES4548D, ES4524D manual Creating QoS Policies, Policy Map, 56-2, 56-3