19

Bandwidth Management

This chapter describes the functions and configuration of bandwidth management with multiple levels of sub-classes.

19.1 Bandwidth Management Overview

Bandwidth management allows you to allocate an interface’s outgoing capacity to specific types of traffic. It can also help you make sure that the ZyWALL forwards certain types of traffic (especially real-time applications) with minimum delay. With the use of real-time applications such as Voice-over-IP (VoIP) increasing, the requirement for bandwidth allocation is also increasing.

Bandwidth management addresses questions such as:

•Who gets how much access to specific applications?

•What priority level should you give to each type of traffic?

•Which traffic must have guaranteed delivery?

•How much bandwidth should be allotted to guarantee delivery?

Bandwidth management also allows you to configure the allowed output for an interface to match what the network can handle. This helps reduce delays and dropped packets at the next routing device. For example, you can set the WAN interface speed to 1024 kbps (or less) if the broadband device connected to the WAN port has an upstream speed of 1024 kbps.

19.2 Bandwidth Classes and Filters

Use bandwidth classes and sub-classes to allocate specific amounts of bandwidth capacity (bandwidth budgets). Configure a bandwidth filter to define a bandwidth class (or sub-class) based on a specific application and/or subnet. Use the Class Setup screen (see Section 19.12.1 on page 359) to set up a bandwidth class’s name, bandwidth allotment, and bandwidth filter. You can configure up to one bandwidth filter per bandwidth class. You can also configure bandwidth classes without bandwidth filters. However, it is recommended that you configure sub-classes with filters for any classes that you configure without filters. The ZyWALL leaves the bandwidth budget allocated and unused for a class that does not have a filter or sub-classes with filters. View your configured bandwidth classes and sub-classes in the Class Setup screen (see Section 19.12 on page 358 for details).

The total of the configured bandwidth budgets for sub-classes cannot exceed the configured bandwidth budget speed of the parent class.

 

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ZyWALL 2 Plus User’s Guide