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Minasi c01.tex V3 - 05/29/2008 9:45pm Page 8
8 CHAPTER 1 WHY NETWORK?
run the cable through a false ceiling or through air ducts, you may need special cable designed
for that purpose (often called plenum cable). Plenum cable resists burning and doesn’t produce
as many noxious chemicals if it does burn, but it costs a lot more than standard cable. Check
the local electrical code to ensure you use the right kind of cable for a specific purpose.
Hub A hub is the least expensive connectivity solution for a network. You connect one end
of the cable into the NIC and the other end into the hub. Voil
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a, you are now part of the network.
Every computer or other device (such as a printer) that wants to be part of the network has the
same connection setup. Hubs can usually have 2, 4, 8, 16, or 32 computers or other devices con-
nected to them, with 8 being the most common. Each connection to a hub is a port. You should
buy a hub with enough ports to support all the devices on your network, with a few to spare.
When you run out of ports, you can purchase another hub, connect the two hubs together using
a special port, and then plug additional computers into the new hub. Connecting multiple hubs
together is daisy chaining. Because hubs are very simple devices, they are also extremely reli-
able. However, the reliability and cost savings comes at the price of performance and ease of
maintenance. If you need a high-speed connection or you have many devices to connect, then
a switch is a better option than using a hub. The most important characteristic of a hub is the
connection speed it supports. The connection speed must match the speed of the NICs on a
network.
Switch Switches work precisely the same as hubs from the outside. You connect one end of
the cable into the NIC and the other end into the switch to create a connection to the network.
However, switches include additional internal circuitry and provide performance benefits. A
switch can make smart connections between two devices on the network to speed commu-
nication between them. When working with a hub, all of the computers on the network hear
the message that another computer sends, but switches direct the message specifically to the
computer that needs to hear it. In addition, switches normally contain diagnostic hardware to
make it easier to find problems on your network. Of course, you don’t get this extra circuitry
free — switches cost more than hubs do. As with hubs, the switch connection speed must
match the connection speed of NICs on the network.
Router A router is similar to a switch or hub, but it includes something extra — the ability
to connect to the outside world. A router is similar to a computer with two NICs in it. One set
of connections is for the local network, while the second set of connections is for the outside
world. The vendor labels the connections so you can’t make a mistake in creating the required
connections. Routers also include some of the features of a server, including a firewall for secu-
rity purposes. The features you obtain with the router depends on the kind of router you buy.
For example, some routers include special support for standard TCP/IP features, and some
even include a wireless access point (WAP) to connect with wireless devices. Make sure you
get a router that includes all the features you need. For example, if you have wireless devices,
then getting a router with a built-in WAP is a better buy than purchasing the WAP separately.
Network-Ready Device In days gone by, most devices such as printers, camcorders, and
cameras were dependent on a connection with a computer to gain network connectivity. You
plugged the device into the computer and shared the device with others on the network, and
then other people would access the device through this shared connection. This approach to
networking wastes resources because you now need a computer to create the required connec-
tion. Network-ready devices have a NIC built into them and provide the software required to
create the network connection. You access a network-ready device the same way you do any
computer on the network. The network-ready devices do cost more than standard devices,
so you need to weigh the added cost of the device against the cost of using the computer to