The Trunk Summary Screen; Figure 190 Weighted Round Robin Algorithm Example; Figure 191 Spillover Algorithm Example - ZyXEL Communications ZyWALL USG 100 Series User Manual

Chapter 11 Trunks

Figure 190 Weighted Round Robin Algorithm Example

Spillover
The spillover load balancing algorithm sends network traffic to the first interface in the trunk
member list until the interface's maximum allowable load is reached, then sends the excess
network traffic of new sessions to the next interface in the trunk member list. This continues as
long as there are more member interfaces and traffic to be sent through them.
Suppose the first trunk member interface uses an unlimited access Internet connection and the
second is billed by usage. Spillover load balancing only uses the second interface when the
traffic load exceeds the threshold on the first interface. This fully utilizes the bandwidth of the
first interface to reduce Internet usage fees and avoid overloading the interface.
In this example figure, the upper threshold of the first interface is set to 800K. The ZyWALL
sends network traffic of new sessions that exceed this limit to the secondary WAN interface.

Figure 191 Spillover Algorithm Example

Finding Out More
• See Section 5.4.3 on page 117
• See Section 11.3 on page 279
• See Section 6.6 on page 158

11.2 The Trunk Summary Screen

Click Network > Interface > Trunk to open the Trunk screen. This screen lists the
configured trunks and the load balancing algorithm that each is configured to use.
276
for related information on the Trunk screens.
for more background information on trunks.
for an example of how to configure load balancing.
ZyWALL USG 100/200 Series User's Guide