ZyXEL Communications NXC-8160, Руководство пользователя

Страница: 43 / 205

Chapter 4 WLAN Settings
NXC-8160 User’s Guide
43
ESSID
A Service Set Identifier (SSID) is a group of access points connected to a wired LAN on the
same subnet. An SSID uniquely identifies each group. All access points and their associated
wireless stations in the same group must have the same SSID. The Extended Service Set
Identifier (ESSID) is a variation of the SSID-type. See
Appendix E on page 179 for more
information on Wireless LANs and SSIDs.
Normally, the AP acts like a beacon and regularly broadcasts the SSID in the area. You can
hide the SSID instead, in which case the AP 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 devices
to get the SSID. In addition, unauthorized devices can still see the information that is sent in
the wireless network.
4.2 The ESSID Settings Screen
Click WLAN > ESSID Definition to open this screen. This is where you can configure the
device’s wireless settings, such as ESSID and authentication security, among other things.
The ESSID is the name of a network managed by the NXC-8160. When a computer wants to
connect wirelessly to the network, it must use one of the ESSIDs transmitted by the NXC-
8160 in order to make the initial connection. An individually configured ESSID contains a set
of permissions and privileges for any computer that connects to the NXC-8160 using that
ESSID. For example, you can require MAC authentication for a particular ESSID, or set up a
captive portal (see
Section 7.7 on page 86 for details) to intercept all network traffic on first
connect, to name a few.
Each channel broadcast by the NXC-8160 can support multiple ESSIDs, allowing you to
create a number of “virtual” networks on the same channel.
The NXC-8160 supports the following parameters:
• Each radio is assigned one channel
• Each channel can support up to 16 different ESSIDs
• Each ESSID can be associated with a VLAN tag
• The same ESSID name can be repeated for different channels