ZyXEL Communications P-3202HN-Ba, Руководство пользователя

Страница: 91 / 250

Chapter 8 Wireless LAN
IAD User’s Guide
91
8.10.2 Additional Wireless Terms
The following table describes some wireless network terms and acronyms used in
the IAD’s Web Configurator.
8.10.3 Wireless Security Overview
The following sections introduce different types of wireless security you can set up
in the wireless network.
8.10.3.1 SSID
Normally, the IAD acts like a beacon and regularly broadcasts the SSID in the
area. You can hide the SSID instead, in which case the IAD does not broadcast the
SSID. In addition, you should change the default SSID to something that is
difficult to guess.
This type of security is fairly weak, however, because there are ways for
unauthorized wireless devices to get the SSID. In addition, unauthorized wireless
devices can still see the information that is sent in the wireless network.
8.10.3.2 MAC Address Filter
Every device that can use a wireless network has a unique identification number,
called a MAC address.
1
A MAC address is usually written using twelve hexadecimal
Table 24 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
IAD. 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 IAD.
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 IAD does, it cannot communicate with the
IAD.
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.