FREE ESSAY ON DSL

DSL

Digital Subscriber Line
Digital Subscriber Line new technology that takes advantage of standard copper telephone
line to provide secure, reliable, high-speed Internet access. DSL refers to the family of
digital subscriber line technologies, such as ADSL, HDSL, and RADSL. Connection speed for
DSL ranges from 1.44 Mbps to 512 Kbps downstream and around 128 Kbps upstream. Unlike
traditional connections DSL such as analog modems and IDSN, DSL deliver continuous
"always on" access. That means multimedia-rich websites, e-mail, and other online
applications are available anytime. DSL makes it possible for you to remain online even
while you're talking on the telephone-without jeopardizing the quality of either
connection. 
DSL is available in a spectrum of speeds. Some are best home use, while others are
designed to accommodate rigorous business demands. Whether for business or the home, DSL,
offers unsurpassed price/performance value compared to other online options. There are
the five facts that one should know about DSL. 
It is remarkably fast. With DSL service, you can benefit from Internet speeds that are up
to 12 minutes faster than a typical ISDN connection and 50 times faster than traditional
28.8 Kbps modems. This means that in the 12 seconds it takes to read this information,
you could have downloaded a 2 megabyte presentation file or web photograph. It would take
10 more minutes (600 more seconds!) to download the same with a traditional 28.8 Kbps.
It's highly reliable. One can depend on DSL because its proven technology takes full
advantage of the existing telecommunications infrastructure. It's inherently secure. DSL
network provides a dedicated Internet connection via private telephone wires, you can
bypass dial-up intruders or shared network hackers. Unlike traditional dial-upp modems or
cable modems. DSL protects your valuable data with the most secure connection available.

It's surprising affordable. DSL is widely recognized as the most cost-effective
connectivity solution for small buisness. DSL delivers industrial- strength like speed to
multiple users at only 25% of typical TI costs. There is no better price option
available. DSL is also an exceptional value for home users. At about $2 a day for
services that meets the needs of most people. 
The connection is always on. It's ready to run every minute of the day. There's no more
logging on and off. No more busy signals or disconnects. This gives you the freedom to
focus on what you want to accomplish on line rather than focusing on trying to get
connected. In fact, you can be more productive because the power and immediacy of the
internet is continuously available at your fingerprints.
DSL is a network access technology that telephone companies have been testing and
refining since the beginning of the decade. It has unique advantages that it can provide
high speed digital transmission over 750 million ordinary phone lines that make up our
communication infrastructure. 
Speed 384 Kbps 128 Kbps 28.8 Kbps
2 Mb image files 72 seconds 3.6 minutes 15.9 minutes
72 MB video 43 minutes 2.2 hours 9.6 ours 
DSL enables today's users to gain continuous access to the Internet or corporate Local
Area Neworks (LANs) at an amazing rate of 25 times to 100 times faster than the 56.6
kilobits per seconds modems. DSL modems use sophisticated digital coding techniques that
squeezes up to 99% or more capacity out of an ordinary phone line, making a super-fast
network access possible. 
DSl was originally developed to support video on demand services that telephone companies
planned to offer to compete with cable companies. However most companies have backed away
from these services. Instead, DSL's high speed capacity have made it the technology of
choice for the majority of the lines leased by large corporation for private voice and
data networks. 
DSL comes in many different varieties:
ADSL
Asymmetric or Asynchronous Digital Subscriber Line service transmits faster on direction
(1.544 Mbps downstream to the house) than the other (384 Kbps to the the telephonw
company's CO). ADSL bases services offer high power Internet users who want to download
large files and other resources from the Web in less time than it normally would.
SDSL
Symmetric Digital Subscriber Line (also know as the single line) provides 144 Kbps of
bandwidth in both directions. SDSL's is cheaper than other services provided by DSL. It
has the ability to transfers information in both directions. It's ideal for most buisness
applications, including internet access, or connecting remote offices of large
corporations.
IDSL
ISDN Digital Subscriber line service is designed to accommodate users that already
invested in ISDN. This is buisness oriented service, it provides ISDN signalling at 144
Kbps over a DSL circuit. It plugs into existing ISDN equipment a local carrier's CO.
HDSL
High speed Digital Subscriber Line, it runs approximately 6 Mbps. This service is used to
provide T-1 digital servies (1.544 Mbps) over standard telephone lines.
VDSL
Very High-Speed Digital Subscriber Line is the