Configuring Load Balancing; Least Load First; Figure 99 Least Load First Example - ZyXEL Communications 5 Series User Manual

Table 35 NETWORK > WAN > General (continued)
LABEL
Allow Trigger Dial Select this option to allow NetBIOS packets to initiate calls.
Apply
Reset

9.2.2 Configuring Load Balancing

To configure load balancing on the ZyWALL, click NETWORK > WAN in the navigation
panel. The WAN General screen displays by default. Select Active/Active Mode under
Operation Mode to enable load balancing on the ZyWALL.
The WAN General screen varies depending on what you select in the Load Balancing
Algorithm field.

9.2.3 Least Load First

The least load first algorithm uses the current (or recent) outbound and/or inbound bandwidth
utilization of each WAN interface as the load balancing criteria for making decisions on how
how to route traffic. The outbound bandwidth utilization is defined as the measured outbound
throughput over the available outbound bandwidth. The inbound bandwidth utilization is
defined as the measured inbound throughput over the available inbound bandwidth. The two
ratios are indexes used to calculate which WAN interface is less utilized at the time. A new
LAN-originated session is distributed to the less utilized WAN interface.
Example 1
The following figure depicts an example where both the WAN interfaces on the ZyWALL are
connected to the Internet. The configured available outbound bandwidths for WAN 1 and
WAN 2 are 512K and 256K respectively.

Figure 99 Least Load First Example

If the outbound bandwidth utilization is used as the load balancing index and the measured
outbound throughput of WAN 1 is 412K and WAN 2 is 198K, the ZyWALL calculates the
load balancing index as shown in the table below.
ZyWALL 5/35/70 Series User's Guide
DESCRIPTION
Click Apply to save your changes back to the ZyWALL.
Click Reset to begin configuring this screen afresh.
Chapter 9 WAN Screens
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