ZyXEL Communications P-870HW-51A V2, Руководство пользователя

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Chapter 7 Wireless LAN
P-870HW-51a v2 User’s Guide
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7.9.2 Additional Wireless Terms
The following table describes some wireless network terms and acronyms used in the ZyXEL
Device’s Web Configurator.
7.9.3 Wireless Security Overview
The following sections introduce different types of wireless security you can set up in the
wireless network.
7.9.3.1 SSID
Normally, the ZyXEL Device acts like a beacon and regularly broadcasts the SSID in the area.
You can hide the SSID instead, in which case the ZyXEL Device 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.
7.9.3.2 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 characters
2
; for
example, 00A0C5000002 or 00:A0:C5:00:00:02. To get the MAC address for each device in
the wireless network, see the device’s User’s Guide or other documentation.
You can use the MAC address filter to tell the ZyXEL Device which devices are allowed or
not allowed to use the wireless network. If a device is allowed to use the wireless network, it
still has to have the correct information (SSID, channel, and security). If a device is not
allowed to use the wireless network, it does not matter if it has the correct information.
Table 27 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.
1. Some wireless devices, such as scanners, can detect wireless networks but cannot use wireless networks.
These kinds of wireless devices might not have MAC addresses.
2. Hexadecimal characters are 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, and F.