ZyXEL Communications VMG1312-T10C, Руководство пользователя

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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.