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These are the most common types of
wireless network, which are also often called Wi-Fi®
networks. There are three varieties of 802.11 wireless networks:
802.11a, 802.11b, and 802.11g. We cover them in more detail in the Home
Networking section. There are also Bluetooth® enabled
wireless home networks, although they may not be the optimal choice to
serve as the backbone for large data transfers between multiple
computers. Bluetooth technology does however offer many, many advantages
for connecting computers with smaller devices like printers and cameras.
So when people refer to "wireless home network," odds are they mean one
of the flavors of 802.11.
Access point
Most 802.11 networks, called
infrastructure networks, use a central piece of hardware called an
access point. Access points, or APs, are sometimes referred to as
hubs, routers, or base stations. You'll also see
terms like residential gateway or Internet gateway device
in documentation. Despite the number of synonyms, they all mean the same
thing on a wireless network. All computers on the network communicate
through this piece of hardware. An access point acts as a sort of grand
central station that manages every piece of data sent between computers.
Ad hoc
A small percentage of 802.11
networks, called ad hoc networks, use direct computer-to-computer
communication. An ad hoc network allows computers to "talk" (send data)
directly to and from one another.
For an ad hoc network to work, each
computer on the network needs a wireless network card installed, and you
must set your wireless network cards (installed in each computer on the
network) to Ad Hoc mode.
This is not the same as a firewall.
You need both. Firewalls are intended to help you to keep intruders and
dangerous software such as computer worms out of your computers;
antivirus software helps keep viruses out and helps you know what to do
if something does get in. Firewalls, for instance, won't catch viruses
sent in e-mail.
Since there is a constant real
danger of hackers writing viruses, worms, and other problem software
programs, you need to keep your antivirus software up to date. Many
companies make excellent antivirus software and update it regularly. If
a new virus arrives on your computer, your antivirus software tells you
what the virus is and how to clean it up.
A wired network can communicate
with a wireless network using a network bridge (usually just
called a bridge). If you set up an 802.11 wireless network,
you'll probably need to share something on your network that's wired—an
Internet connection or a device, such as a printer. Almost every
wireless network has a few wired connections in it somewhere. This means
you need to translate data from one network to another. Traditionally,
this work has been done by a piece of hardware called a bridge.
Currently, many routers are used to do this work instead, and bridges
aren't needed. You might still hear talk of bridges from some
salespeople. Windows XP and Windows XP Service Pack 2 both have network
bridging capabilities built in.
DHCP
You can probably get by without a
deep understanding of how Dynamic Host Configuration Protocol
(DHCP) works and enjoy your home network for years, but this term may
come up in discussions about connecting a wireless network to the
Internet.
If you have an access point that
acts as a router on your wireless network, DHCP enables the router to
assign temporary Internet Protocol (IP) addresses to the computers on
your network when you go online. Many broadband routers now perform this
function as well, even units that don't come with a built-in hub.
When you troubleshoot an Internet
connection problem or configure your wireless network's Internet
connection equipment, you may come across this term.
File sharing
One of the benefits of networking
for the home, and maybe even more so for a small business, is file
sharing. File sharing is as simple as it sounds—more than one
computer, and more than one user, can share access to a file.
Want to listen to music files from
the computer in the next room? You'll use file sharing. Same goes for
watching a movie file when the computer storing the file isn't the one
that you want to show the movie on (maybe you want to watch it on a
bigger monitor, or even your TV). Working together on a project and
updating a word processing or spreadsheet file—collaborating on a
proposal, for example? You'll use file sharing.
Many first-time home network users
are surprised to find out how much time they save—and how much more they
get done—using this most basic feature of networking. Sharing movies,
music, photos, and other files just clinches the deal.
Firewalls
do many things. They are intended to help your PC security efforts by
acting as guards at the gate, to assist with making sure only approved
data moves in and out of your computer. Data comes in small packets
(they're really called "packets"—one of the more descriptive technical
terms in computing), and a firewall checks each packet's permissions
before allowing it to proceed. Computers allow data in and out through
doors called ports. You can't turn your computer around and look
at a port; it's more like an engineering metaphor. Firewalls open and
close the ports. You decide which ports stay open, and which programs
get to use them. Firewalls also help to keep prying eyes out of your
computer, which in turn helps to protect private information.
Microsoft Windows XP includes a
built-in firewall, but many other companies sell firewalls of their own,
which you can install and run on computers running Windows XP.
Manufacturers of network equipment also include firewalls in the
equipment they sell.
You should run a firewall on each
piece of equipment on a network, but you usually shouldn't run more than
one on any given computer. If you have a firewall installed on a
computer running Windows XP and both that firewall and the Windows XP
firewall are turned on, you can have policy conflicts between the two.
You could lose a great deal of computing speed, especially when
downloading files from the network or the Internet.
Hub
A network hub is like the
hub of a wheel. It joins communication lines at one central location,
providing a common connection to all the computers and devices on your
network. With a hub, your computers are connected to one another but
they don't transmit data as quickly as they can with a device called a
switch. When you expand a network to more than about four
computers (this is a very rough rule of thumb), a hub's lack of power
will become more apparent, and you may want to change to a switch. You
can use a hub where you'd use a switch, and you'll likely save money,
but it's slower.
IP address
An Internet Protocol (IP)
address is the unique string of numbers that identifies a computer and
looks something like this: 192.168.0.99—four sets of digits divided by
periods. An IP address is a little like having a phone number tied to
one specific phone. Your computer's IP address will change if you log on
to the Internet through a different network, so don't assume that
knowing your IP address at work will apply at home, for example. Since
the "servers" that send data to and from the Internet have to know where
they're sending things, they need a way to identify which computer gets
which data.
If you're ever talking to a
technician about your network, particularly when discussing Internet
connections, you may be asked for your computer's IP address. You'll
almost certainly never need to memorize it like a phone number, but
sometimes it helps to know what one looks like when you're looking for
the information.
Latency
is the time a computer spends waiting before a download (or other data
request) starts. It's slightly different from bandwidth.
Bandwidth is the time required to move the data. If you have a
low-latency or "low ping" connection, your downloads start sooner. If
you have a high-bandwidth connection, your downloads finish sooner.
Think of a garden hose versus a fire hose: if the garden hose starts
running sooner, it has lower "latency" than the fire hose. But the fire
hose moves more water, so its "bandwidth" is higher.
NAT router with wireless
When you have a wired network (like
Ethernet®), and also a wireless network, you can link the two with a
NAT router with wireless support. This is a NAT router with an
802.11 access point and bridge built into it. Sometimes these are called
cable/DSL routers with wireless. In the store, read any packaging
carefully to make sure you're getting what you need, especially when
buying a router. Combination units like these aren't always labeled
exactly the same way.
With this type of router, you can
enjoy all the benefits of going online on computers connected two
different ways: wirelessly and wired. For example, you might have a
small Ethernet network with an Internet connection at home, and
occasionally you bring home a laptop from work. You might need a
wireless Internet connection for the laptop, to get files and e-mail. A
NAT router with wireless support lets you connect that laptop to your
home Internet connection.
When you buy a router, often the
only hardware left to buy is a network card (adapter) for each computer.
This can sometimes even produce a net savings in hardware costs, but
centralizing the hardware devices is the main benefit.www.tartoos.com
PC Card
The Personal Computer Memory Card
International Association (PCMCIA) developed the PCMCIA Card—usually
just called a PC Card. About the size of a credit card, it's
often the card in a laptop that you plug a network connection into.
PCI
Peripheral Component
Interconnect (PCI) and
Universal Serial Bus (USB) connections are two ways to plug
equipment into your computer.
PCI cards usually require opening
your machine and installing them. If the computers you want to network
don't have PCI cards installed, you may need to pay someone to install
them if you're not comfortable doing it yourself. This inconvenience
often pays off since PCI cards can offer faster performance, more
reliability, and more flexibility in communicating with other kinds of
hardware than USB cards. See also USB.
Printer sharing
A fundamental benefit of networking
your computers is that you can buy one printer for everyone's use. Once
you connect a printer to a computer on the network, turn that computer
on, and run the Network Setup Wizard in Windows XP, that printer is
available to other computers on the network running Windows XP.
If you have Windows Messenger
installed on two or more computers on a network, you can use the Remote
Assistance feature built in to Windows Messenger to help another person
get work done, or get a problem solved, on their computer.
This feature of Windows Messenger
is popular with parents of younger children (and in many cases, children
of parents new to technology). It's also handy at work when one person
regularly helps others solve technical problems.www.tartoos.com
Router
A router is the device used
to connect to the Internet in most networks. In some cases (especially
certain 802.11 wireless devices), routers have networking functionality
built in. Routers allow Internet communications (such as Web surfing,
file downloading and uploading, sending and receiving e-mail) to flow
both ways, while helping to keep your network activity private from the
outside world.
Routers usually come with a
firewall built in. This should be used in addition to the firewalls on
the computers on your network.
Switch
A switch is a connection
device that enables data to move to and from several computers on your
network at the same time. A switch costs more than a hub, but it can
move data much more quickly when several people are using the network at
once. In smaller networks (usually, fewer than four computers), you can
use a hub where you'd use a switch if cost is a concern. See also Hub.
USB
Universal Serial Bus
(USB) is the alternative to Peripheral Component Interconnect
(PCI) connectivity. Every computer on a network needs the right kind of
network card to communicate with the network. You can usually get the
right kind of card for your network in either PCI or USB form.
The great thing about USB
connections is how easy they are to use—most new computers have USB
slots right on the front, and maybe many more on the back. You just plug
in the jack and you're nearly done. See also PCI.
With laptops, deciding whether to
use USB means deciding between USB and a PC Card. See also PC Card.
See antivirus.
WEP
Wired Equivalent Privacy
(WEP) is the old standard for security and data protection on a wireless
network. The current standard is WPA, which is much stronger but is not
yet supported on all devices.
When people say "wireless
networking," they might be referring to Bluetooth wireless technology or
one of the flavors of 802.11 wireless networking. Usually, they mean
802.11.
Wireless networks enable you to
move data without having to run wires from computer to computer.
Wireless networks have good range, so even with relatively large spaces
between computers you can get good performance from them.
WPA
Wi-Fi® Protected
Access (WPA) is the current
standard for security and data protection on a wireless network. It
helps prevent unauthorized users from connecting to your network.
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