Load Balancing - ZyXEL Communications ZyWALL 110 User Manual

Chapter 8 Wireless
Figure 146 An Example Four-Channel Deployment
However, some regions require the use of other channels and often use a safety scheme with the
following four channels: 1, 4, 7 and 11. While they are situated sufficiently close to both each other
and the three so-called "safe" channels (1,6 and 11) that interference becomes inevitable, the
severity of it is dependent upon other factors: proximity to the affected AP, signal strength, activity,
and so on.
Finally, there is an alternative four channel scheme for ETSI, consisting of channels 1, 5, 9, 13. This
offers significantly less overlap that the other one.
Figure 147 An Alternative Four-Channel Deployment

8.6.2 Load Balancing

Because there is a hard upper limit on an AP's wireless bandwidth, load balancing can be crucial in
areas crowded with wireless users. Rather than let every user connect and subsequently dilute the
available bandwidth to the point where each connecting device receives a meager trickle, the load
balanced AP instead limits the incoming connections as a means to maintain bandwidth integrity.
There are two kinds of wireless load balancing available on the ZyWALL/USG:
Load balancing by station number limits the number of devices allowed to connect to your AP. If
you know exactly how many stations you want to let connect, choose this option.
For example, if your company's graphic design team has their own AP and they have 10 computers,
you can load balance for 10. Later, if someone from the sales department visits the graphic design
team's offices for a meeting and he tries to access the network, his computer's connection is
delayed, giving it the opportunity to connect to a different, neighboring AP. If he still connects to
the AP regardless of the delay, then the AP may boot other people who are already connected in
order to associate with the new connection.
Load balancing by traffic level limits the number of connections to the AP based on maximum
bandwidth available. If you are uncertain as to the exact number of wireless connections you will
have then choose this option. By setting a maximum bandwidth cap, you allow any number of
ZyWALL/USG Series User's Guide
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