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To
understand broadband technology, you might find it useful to compare the
flow of computer data to the flow of water. Data flows from the reservoir
of the Internet much like water flows through a pipe, into your Internet
service provider (ISP), through to your computer (or local area network
of computers), and back out again.
Bandwidth
is the amount of data that can be transmitted per second. It’s like
the size of the pipe through which the data flows. The greater your bandwidth,
the faster you can accomplish those tasks whose quality is dependent on
speed, such as tuning in videos or music over the Internet, playing online
games, or sending large files.
Bandwidth
is measured by the amount of data it moves per second; typical measurement
units are kilobits per second (Kbps) and megabits per second (Mbps). A
“bit” is the basic unit of electronic data sent or received
by a computer. One kilobit equals roughly 1,000 bits, and one megabit
equals roughly 1,000,000 bits.
A
typical speed for a dial-up modem is 56 Kbps. In contrast, most high-speed
and broadband connections offer much faster speeds, measured in Mbps.
For example, a 1 Mbps broadband connection can transfer data at over 1,000,000
bits per second.
Connection types
Continuing the water analogy, let’s look at a few of the earliest
(and still common) types of Internet connections, in use before broadband
became practical for home and small office use.
Dial-up
A
dial-up connection is the smallest pipe you can use to connect to the
Internet. It is fast enough to read information and download small files,
but it has problems with video connections, multimedia-intensive websites,
and high-speed games. Dial-up connections, by definition, require you
to connect to an ISP over a phone line, so you cannot talk on the phone
and go online at the same time without a second phone line.
ISDN
Integrated
Services Digital Network (ISDN) modems, with speeds up to 128 Kbps over
two phone lines, provide a step up from an ordinary dial-up modem. ISDN
uses more advanced networking protocols to double or even triple the speed
of dial-up modems. However, the pipe is still small. While ISDN can be
used at home, it has not caught on as a standard home network connection,
and its use has mostly been restricted to small offices and computer professionals.
T1
and T3
T1
and T3 connections are high-capacity, always-on network connections that
have been available for some time. They directly connect a local area
network (LAN) to the Internet, usually through a telephone company.
While
T1 and T3 connections are broadband connections (large pipes capable of
moving huge flows of data), they’re prohibitively expensive for
home users. They are typically only used by larger and high-tech organizations.
Enter broadband for the home and small office
None of the previously mentioned connection types is ideal for a home
or small-office customer. But in the late 1990s, broadband connections
became practical for the home with the advent of Digital Subscriber Lines
(DSL) and digital cable connections. These newest broadband options offer
the best of all worlds: high-speed connections at affordable prices.
DSL (better known as Broadband)
DSL
enables you to connect to the Internet over a phone line without interrupting
your phone service. DSL connections are relatively inexpensive, always
on, readily accessible to home users through local telephone companies,
and desirably fast, with speeds that can reach 2 Mbps and higher. DSL
is popular in many urban areas, where existing phone lines support the
connections.
In
addition, a DSL account has a preset amount of bandwidth available for
upload and download. DSL connections don’t share bandwidth with
other users of the same ISP. Sharing of bandwidth can slow the flow of
data.
Digital
cable
At
about the same time that DSL hit the market, cable companies began providing
digital cable connections to their customers. Transmitted over existing
coaxial cable lines, digital cable can provide speeds of 256 Kbps to over
1 Mbps. Cable connections, like DSL connections, are always on.
Cable
broadband services share a set amount of bandwidth with a group of accounts,
such as an apartment building or neighbourhood, so the size of the data
pipe available to an individual user varies depending on how many neighbours
are using the Internet at the same time. When few people are online, data
speeds can be extremely fast; when many are online, connection speeds
can be considerably slower.
Home and small office connection speeds at a glance
The following table of home and small office connection options lists
the speeds of the most popular types of online connections. As you can
see, a broadband connection can provide over 1000 times the speed of a
dial-up connection.
| Connection
type |
Minimum
speed |
Maximum
speed |
| Dial-up
modem |
14.4
Kbps |
56.6
Kbps |
| ISDN |
64
Kbps |
128
Kbps |
| DSL |
128
Kbps |
7.5
Mbps |
| Digital
cable |
64
Kbps |
20
Mbps |
Use
a firewall
Just
as the name implies, a firewall acts as a barrier or buffer zone between
your local network and the Internet. A firewall allows you to specify
what information can be communicated from the computers on your network
to the Internet and from the Internet to the computers on your network.
It checks data packets being transmitted to your network and discards
any suspicious data.
How
to get broadband
The first step in bringing broadband to your home or small office is to
find out what services are available in your neighbourhood. Broadband
services are expanding at record rates. For information about availability
and pricing in your area, check with your telephone company or local cable
supplier, or contact your ISP.
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