ZyXEL Communications Corporation VMG1312T10C Manuel D’Utilisation

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Chapter 6 Wireless
VMG1312-T10C User’s Guide
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6.10  Technical Reference
This section discusses wireless LANs in depth. 
6.10.1  Additional Wireless Terms
The following table describes some wireless network terms and acronyms used in the Device’s web 
configurator.
6.10.2  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 
Channel Width
A standard 20MHz channel offers transfer speeds of up to 150Mbps whereas a 40MHz 
channel uses two standard channels and offers speeds of up to 300 Mbps. 
Select 20MHz if you want to lessen radio interference with other wireless devices in your 
neighborhood or the wireless clients do not support channel bonding.
Select Auto to have the Device configure the wireless channel width automatically.
This field is available only when you set the 802.11 Mode to 802.11n or 802.11b+g+n 
in the Advanced Setup screen.
Apply
Click this to save your changes.
Cancel
Click this to restore your previously saved settings.
Table 22   
Network Setting > Wireless> Advanced (continued)
LABEL
DESCRIPTION
Table 23   
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 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 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 Device does, it cannot communicate with the 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.