QoS Policy Planning Aids (IPQoS Administration Guide)

IPQoS Administration Guide

QoS Policy Planning Aids

Gather information for planning the QoS policy in a format that includes the information that you need for the IPQoS configuration file. For example, you can use the following template to list the major information to be used in the IPQoS configuration file.

Table 2–2 QoS Organizational Template


Class	Priority	Filters	Selectors	Rate	Forwarding?	Accounting?
Class 1	1	Filter 1 Filter 3	Selector 1 Selector 2	Meter rates, depending on meter type	Marker drop precedence	Requires flow-accounting statistics
		Filter 2	Selector 1 Selector 2
Class 2	2	Filter 1	Selector 1 Selector 2	Meter rates, depending on meter type	Marker drop precedence	Requires flow-accounting statistics
		Filter 2	Selector 1 Selector 2

You can divide each major category to further define the QoS policy. The subsequent sections explain how to obtain information for the categories that are shown in the template.

The next task map lists the major tasks for planning a QoS policy.

Table 2–3 QoS Policy Planning (Task Map)


Task	Description	For Instructions
1. Design your network topology to support IPQoS.	Identify the hosts and routers on your network to provide differentiated services.	How to Prepare a Network for IPQoS
2. Define the classes into which services on your network must be divided.	Examine the types of services and SLAs that are offered by your site, and determine the discrete traffic classes into which these services fall.	How to Define the Classes for Your QoS Policy
3. Define filters for the classes.	Determine the best ways of separating traffic of a particular class from the network traffic flow.	How to Define Filters in the QoS Policy
4. Define flow-control rates for measuring traffic as it leaves the IPQoS system.	Determine acceptable flow rates for each class of traffic.	How to Plan Flow Control
5. Define DS codepoints or user priority values to be used in the QoS policy.	Plan a scheme to determine the forwarding behavior that is assigned to a traffic flow when the flow is handled by the router or switch.	How to Plan Forwarding Behavior
6. If applicable, set up a statistics-monitoring plan for traffic flows on the network.	Evaluate the traffic classes to determine which traffic flows must be monitored for accounting or statistical purposes.	How to Plan for Flow Accounting

Note –

The rest of this section explains how to plan the QoS policy of an IPQoS-enabled system. To plan the QoS policy for the diffserv router, refer to router documentation and the router manufacturers' Web sites.