Information Technology Reference
In-Depth Information
A Star Network
An Ethernet Network
A Token-ring Network
Figure 8.5
Star, Ethernet, and tokenring networks.
currently in a network, the addition of a new machine would always
require just one more cable—from the new machine to the central
one. Of course, this approach might involve some congestion of
wires near the central computer, but wiring near the other comput
ers could be reasonably simple.
The star network is often the approach used for telephone sys
tems in small businesses or schools. The central machine in the tele
phone system is an electronic switch, and all telephones in the busi
ness or school have connections to that switch. In using this
network, some communications go directly from the central switch
to a local telephone. For example, were you to pick up the headset
of your classroom's telephone, you would establish communication
with the central machine, and you would hear a dial tone. The dial
tone is the signal from the central machine, letting you know that
your telephone is connected to the network and the system is pre
pared for you to dial. When you dial a number from your tele
phone, however, you're usually trying to establish communication
with another telephone—not the central switch. Back in the early
days of telephones, an operator would serve as the central machine:
You would connect to the operator, the operator would ask you
with whom you'd like to speak, and the operator would make the
connection for you. Times have antiquated these personal connec
tions, but the same basic principle applies as your information is
