Tools for Creating a QoS Policy

The QoS policy for your network resides in the IPQoS configuration file. You create this configuration file with a text editor. Then, you provide the file as an argument to ipqosconf, the IPQoS configuration utility. When you instruct ipqosconf to apply the policy that is defined in your configuration file, the policy is written into the kernel IPQoS system. For detailed information about the ipqosconf command, refer to the ipqosconf(1M) man page. For instructions on the use of ipqosconf, refer to How to Apply a New Configuration to the IPQoS Kernel Modules.

Basic IPQoS Configuration File

An IPQoS configuration file consists of a tree of action statements that implement the QoS policy that you defined in Planning the Quality-of-Service Policy. The IPQoS configuration file configures the IPQoS modules. Each action statement contains a set of classes, filters, or parameters to be processed by the module that is called in the action statement.

For the complete syntax of the IPQoS configuration file, refer to Example 6-3 and the ipqosconf(1M) man page.

Configuring the IPQoS Example Topology

The tasks in this chapter explain how to create IPQoS configuration files for three IPQoS-enabled systems. These systems are part of the network topology of the company BigISP, which was introduced in Figure 2-4.

• Goldweb – A web server that hosts web sites for customers who have purchased premium-level SLAs

• Userweb – A less-powerful web server that hosts personal web sites for home users who have purchased “best-effort” SLAs

• BigAPPS – An application server that serves mail, network news, and FTP to both gold-level and best-effort customers

These three configuration files illustrate the most common IPQoS configurations. You might use the sample files that are shown in the next section as templates for your own IPQoS implementation.