Trunks Overview; Trunks; Trunk Scenario Examples; Load Balancing Introduction - ZyXEL Communications Unified Security Gateway ZyWALL 300 User Manual

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H A P T E R
This chapter shows you how to configure trunks on your ZyWALL. See
115 for related information on these screens.

11.1 Trunks Overview

You can group multiple interfaces together into trunks to have multiple connections share the
traffic load to increase overall network throughput and enhance network reliability. If one
interface's connection goes down, the ZyWALL sends traffic through another member of the
trunk. For example, you can use two interfaces for WAN connections. You can connect one
interface to one ISP (or network) and connect the another to a second ISP (or network). The
ZyWALL can balance the load between multiple connections (see
If one interface's connection goes down, the ZyWALL can automatically send its traffic
through another interface.
You can use policy routing to specify through which interface to send specific traffic types.
You can use trunks in combination with policy routing. You can also define multiple trunks
for the same physical interfaces. This allows you to send specific traffic types through the
interface that works best for that type of traffic, and if that interface's connection goes down,
the ZyWALL can still send its traffic through another interface.

11.2 Trunk Scenario Examples

Suppose one of the ZyWALL's interfaces is connected to an ISP that is also your Voice over
IP (VoIP) service provider. You may want to set that interface as active and set another
interface (connected to another ISP) to passive. This way VoIP traffic goes through the
interface connected to the VoIP service provider whenever the interface's connection is up.
Another example would be if you use multiple ISPs that provide different levels of service to
different places. Suppose ISP A has better connections to Europe while ISP B has better
connections to Australia. You could use policy routing and trunks to send traffic for your
European branch offices primarily through ISP A and traffic for your Australian branch
offices primarily through ISP B.

11.3 Load Balancing Introduction

On the ZyWALL, load balancing is the process of dividing traffic loads between multiple
interfaces. This allows you to improve quality of service and maximize bandwidth utilization.
ZyWALL USG 300 User's Guide
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Trunks

Section 5.4.3 on page
Section 11.3 on page 219).
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