ZyXEL Communications P-660HN-T1H User Manual

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Chapter 8 Wireless LAN
P-660HN-T1H User’s Guide
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8.8.2  Additional Wireless Terms
The following table describes some wireless network terms and acronyms used in 
the ZyXEL Device’s Web Configurator.
8.8.3  Wireless Security Overview
By their nature, radio communications are simple to intercept. For wireless data 
networks, this means that anyone within range of a wireless network without 
security can not only read the data passing over the airwaves, but also join the 
network. Once an unauthorized person has access to the network, he or she can 
steal information or introduce malware (malicious software) intended to 
compromise the network. For these reasons, a variety of security systems have 
been developed to ensure that only authorized people can use a wireless data 
network, or understand the data carried on it.
These security standards do two things. First, they authenticate. This means that 
only people presenting the right credentials (often a username and password, or a 
“key” phrase) can access the network. Second, they encrypt. This means that the 
information sent over the air is encoded. Only people with the code key can 
understand the information, and only people who have been authenticated are 
given the code key.
Table 39   Additional Wireless Terms
TERM
DESCRIPTION
RTS/CTS Threshold
In a wireless network which covers a large area, wireless devices 
are sometimes not aware of each other’s presence.  This may cause 
them to send information to the AP at the same time and result in 
information colliding and not getting through.
By setting this value lower than the default value, the wireless 
devices must sometimes get permission to send information to the 
ZyXEL Device. The lower the value, the more often the devices must 
get permission.
If this value is greater than the fragmentation threshold value (see 
below), then wireless devices never have to get permission to send 
information to the ZyXEL Device.
Preamble
A preamble affects the timing in your wireless network. There are 
two preamble modes: long and short.
 
If a device uses a different 
preamble mode than the ZyXEL Device does, it cannot communicate 
with the ZyXEL Device.
Authentication
The process of verifying whether a wireless device is allowed to use 
the wireless network.
Fragmentation 
Threshold
A small fragmentation threshold is recommended for busy networks, 
while a larger threshold provides faster performance if the network 
is not very busy.