ZyXEL Communications ZyXEL ZyWALL 35 - Manual (Page 143)

ZyWALL 35 User’s Guide
Chapter 7 WAN Screens 141
Figure 48 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.
Since WAN 2 has a smaller load balancing index (meaning that it is less utilized than WAN 1),
the ZyWALL will send the subsequent new session traffic through WAN 2.
7.4.1.2 Example 2
This example uses the same network scenario as in Figure 48 , but uses both the outbound and
inbound bandwidth utilization in calculating the load balancing index. If the measured
inbound stream throughput for both WAN 1 and WAN 2 is 102K, the ZyWALL calculates the
average load balancing indices as shown in the table below.
Since WAN 1 has a smaller load balancing index (meaning that it is less utilized than WAN 2),
the ZyWALL will send the next new session traffic through WAN 1.
Table 40 Least Load First: Example 1
INTERFACE
OUTBOUND
LOAD BALANCING INDEX
(M/A )
AVAILABLE (A) MEASURED (M)
WAN 1 512 K 412 K 0.8
WAN 2 256 K 198 K 0.77
Table 41 Least Load First: Example 2
INTERFACE
OUTBOUND INBOUND
AVERAGE LOAD
BALANCING INDEX
(OM / OA + IM / IA) / 2
AVAILABLE
(OA)
MEASURED
(OM)
AVAILABLE
(IA)
MEASURED
(IM)
WAN 1 512 K 412 K 256 K 102 K ( 0.8 + 0.4) / 2 = 0.6
WAN 2 256 K 198 K 128 K 102 K ( 0.77 + 0.8 ) / 2 = 0.79