Dial-up Options
"56K" connections.
The most-common, and least
expensive, type of Internet
connection involves a computer with
a standard internal V.90 modem with
an ordinary phone line running from
a computer to a phone jack. This
type of connection, often referred
to as a "dial-up" connection or
"standard dial-up," requires you to
establish Internet connectivity with
an Internet service provider, often
referred to as an "ISP."
This method requires you to have an
ISP-provided telephone number that
your modem dials into to establish
the connection. Because of the
data-transfer limitations of phone
lines, only up to 56 kilobits per
second (known as 56Kbps or, more
popularly, 56K) of data can be
transferred at one time. In the
world of Internet connections, this
is considered slow.
This type of connection is fine for
sending and receiving e-mail
messages and for viewing web pages
comprised of mostly text. But this
type of connection is problematic
when sending and receiving large
file attachments, viewing
multimedia-rich web pages, and
hearing and viewing audio and video
files.
A
56K connection is recommended as an
inexpensive solution for small
businesses and home offices with
simple e-mail and limited web
surfing needs that don't require
extensive use of multimedia or the
exchange of large file attachments.
ISDN.
ISDN (Integrated
Digital Services Network) is a
more-advanced type of dial-up
connection that can transfer data up
to 128Kbps, double that of a
standard phone-line connection.
This setup is a true digital
connection, rather than the
digital-analog combination of
standard dial-up, allowing it to use
ordinary phone wires at double the
normal data transfer capacity.
The faster speed means it costs more
than standard dial-up, but it's
better at handling data transfers,
and the true digital connection
means it's more reliable than
standard dial-up connections.
Many businesses use ISDN for
telecommuting or remote workers who
need to communicate to a business's
main office. That's because ISDN
give workers access to standard
office communications tools, such as
an Internet connection, e-mail and
fax capabilities, and telephony,
because it can simultaneously
support voice and data transmission.
ISDN requires additional hardware
beyond a standard dial-up
connection. A dual telephone wire
setup dedicated solely to the ISDN
connection is required as well as an
ISDN router in your office. (A
router is a network device use to
data between two or more networks).
This equipment typically is
installed by your local phone
company.
It's also a good idea to first check
with the phone company to ensure
ISDN is available in your area
before buying any hardware, as about
10 percent of the United States
lacks ISDN service.
Broadband Connections
DSL.
DSL (Digital Subscriber Line)
technology uses the same twisted
copper telephone lines as standard
dial-up and ISDN, but with
drastically improved speed. DSL can
be up to 140-plus times faster than
56Kbps modems, and up to more than
60 times faster than ISDN. It's also
popular because it's relatively
inexpensive compared to other
broadband connection options.
The increased speed found with this
type of Internet connection is
achieved by using sophisticated
modulation technology in a direct
connection between DSL-connected
computers and the telephone company.
In fact, your computers' physical
distance from the phone company
determines, in large part, the speed
of your DSL connection. That's why
it's a good idea to subscribe to DSL
only if the phone company providing
it is located close by, at least
within three or four miles.
There are different types of DSL
available. The most common are ADSL
(Asymmetrical Digital Subscriber
Line) and SDSL (Symmetrical Digital
Subscriber Line).
With ADSL, data downloads take place
up to 8 megabytes per second (Mbps),
and uploads are up to 1Mbps. This
type of service is ideal for
businesses needing access to the
World Wide Web and the ability to
send and receive large multimedia
files.
SDSL offers the same download and
upload speeds: up to 1.544 megabits
(not megabytes) per second. This
symmetrical speed makes it ideal for
e-mail and web servers on small
networks as well as interoffice
communications. It is also often
more expensive than ADSL and doesn't
support standard phone services.
Broadband connections such as DSL-in
a huge advantage over standard
dial-up and ISDN-are an "always-on"
connection, meaning computers with
DSL connection have continuous
connections to the Internet. This is
an important consideration if you
have many workers who need frequent
access to the Internet and the
ability to send and receive large
data files.
Cable.
A cable Internet
connection, unlike the previous
types of connections we've
discussed, doesn't use phone lines
at all. Instead, this technology
takes advantage of existing
television cable lines and "cable
modems" to transfer data at very
fast rates: 42Mbps for downloads and
10Mbps for uploads.
This type of connection is heavily
marketed by cable companies to
residential areas, given that most
homes are already wired with
television cables. This makes it a
popular choice for home offices,
although the subscription rates are
higher than dial-up connections and
DSL. Still, the price is generally
reasonable for small businesses and
the high-speed, always-on connection
makes for a highly reliable and very
fast Internet connection.
Because of the continuous connection
that flows through phone cables,
cable connections, like DSL
connections, are not highly secure
from unauthorized entry by hackers.
It's highly recommended that
computers with these types of
connection are protected by a
firewall (a set of related hardware
and software used to protect a
network).
T1 and T3.
These high-speed Internet voice and
data networks are very expensive and
recommended only for larger
companies using a computer network.
A
T1 line is a high-speed, always-on,
highly reliable connection
established usually with fiber-optic
lines that can carry 24 digital
voice channels or data at a rate of
up to a phenomenally fast 1.544
megabits per second. T1 connections
are often used for both a company's
phone system as well as a
high-speed, always-on Internet
connection. A T1 connection is
usually shared by many workers at a
company simultaneously needing
continuous high-speed Internet
access.
A
T3 line is used most often for huge
networks, like those that comprise
the Internet or for hosting heavily
visited websites. Digital data is
transferred at 44.746 megabits per
second, a huge broadband connection
needed by only the largest networks
and website hosts.
by
Robert H. Fraass on Friday, March
11, 2005
