Chapter 4 Wireless Technology
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The Internet connection connects to the Cable or DSL modem, and the
Ethernet cable connections connect to computers using network cable. The reset
button is used to reset the router confi guration to the default confi guration set
by the manufacturer. The electrical power connection connects to the electrical
power converter.
Wireless routers are commonly encountered today and incorporate features
such as Wireless Access Point (WAP) and Dynamic Host Confi guration Protocol
(DHCP). DHCP is a feature that automatically issues IP addresses to wireless
client devices.
Wireless devices can be confi gured in two different confi gurations: Ad
hoc and infrastructure mode. In ad hoc mode, wireless devices are free to
communicate with each other and all devices are considered equal. Ad hoc
mode does not use a router or WAP to control the connections between devices.
In infrastructure mode, a WAP is used to control communication between
devices. Wireless routers incorporate the WAP feature. Thus, the router controls
communication between wireless devices and wired devices connected to the
same router. Wireless devices such as routers and WAPs are also referred to
at times as bridges because they bridge the connection between two dissimilar
media types: wireless and cable.
The Service Set Identifi er (SSID) is the name used to identify the wireless
network. Manufacturers assign a default SSID to their wireless devices. For
example, D-Link uses “WLAN” or “Default,” Netgear uses “Wireless” or
“NETGEAR,” Linksys uses “Linksys,” and 3Com uses “WLAN” or “3Com.” You
can usually locate the default SSID as well as the default user name and password
to access the wireless router setup program by conducting a search on the Internet.
Because it is so easy to locate the default SSID and user name and password, the
default values are considered an extreme security risk. You can actually perform
a Google search for the default user name and password for most router devices.
During or after the initial confi guration, you should change the SSID to a name
other than the default name. Wireless devices from the same manufacturer will
automatically connect to other wireless devices using the same SSID unless they
are encrypted or have password authentication confi gured. The default SSID, user
name, and password can be reset to the original manufacturer’s values by pressing
the reset button on the router for approximately 15 seconds or more.
The default wireless channel, or dedicated frequency, also varies according
to manufacturer. In the United States, the FCC has assigned 11 wireless channels
for use with wireless devices. Each wireless device in the wireless network
Internet
connection
Ethernet cable
connections
Reset
button
Electrical
power connection