CHAPTER 2
LAN HARDWARE
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Upon completing this chapter, you should be able to do the following:
Explain how to install, inspect, and test network components.
Describe how to make physical connections to networks.
Explain the function of a network server.
As noted in chapter 1, if the hardware, network
software, application software, and cabling were all
supplied by the same manufacturer, we would have
relatively few problems to contend with when we
design and implement a network. The answers to many
hardware and software incompatibilities are found in
the use of interfaces. These various types of interfaces
(bridges, gateways, routers, and so on) allow networks
to be compatible with one another.
NETWORK COMPONENTS
More and more, LANs are becoming part of larger
networks. By connecting LANs together, any
peripheral device, such as external hard disk, printer, or
plotter can be shared by all users of the networks. This
makes more efficient use of expensive peripherals.
Repeaters can be used to amplify electrical signals;
which, in turn, allows transmissions to travel greater
distances. Bridges (also known as bridge servers) make
it possible to interconnect like LANs; that is, two
similar networks. Routers enable networks to
communicate using the most efficient path. Brouters
combine the functions of a bridge and a router.
Gateways (also known as gateway servers) make it
possible to interconnect unlike LANs; that is, two
dissimilar networks.
INSTALL COMPONENTS
The installation of network components is
dependent on the particular type of component, the
manufacturer, and the type of cable being used. When it
comes to installing one of these components, read the
instructions that are supplied with the component to
make sure that you install it properly.
Repeaters
Repeaters are used to amplify electrical signals
carried by the network. They work at layer 1 of the OSI
model—the physical layer. (The OSI model was
covered in chapter 1.) The function of a repeater is to
receive incoming signals (a packet of data), regenerate
the signals to their original strength, and retransmit
them. Repeaters are used to lengthen individual
network segments to form a larger extended network.
That is, repeaters allow a network to be constructed that
exceeds the size limit of a single physical segment by
allowing additional lengths of cable to be connected
(see figure 2-l). There is a catch, however. For a
repeater to be used, both network segments must be
identical-same network protocols for all layers, same
media access control method, and the same physical
transmission technique. This means we could connect
two segments that use the CSMA/CD access methods,
or connect two segments that are running under the
Figure 2-1.—Repeaters used to lengthen individual network
segments.
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