Chapter 24 Bandwidth Management; Bandwidth Management Overview; Bandwidth Classes And Filters - ZyXEL Communications ZyWall 5 Series User Manual

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

24.1 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.

24.2 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
on page 433) 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
The total of the configured bandwidth budgets for sub-classes cannot exceed the configured
bandwidth budget speed of the parent class.

Chapter 24 Bandwidth Management

Bandwidth Management
Section 24.12 on page 431
ZyWALL 5/35/70 Series User's Guide
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H A P T E R
for details).
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