Dial-up
connection
Dial-up Internet access is a form of Internet access that
uses the facilities of the public switched telephone network (PSTN) to
establish a connection to an Internet service provider (ISP) by dialing a
telephone number on a conventional telephone line. The user's computer or
router uses an attached modem to encode and decode information into and from
audio frequency signals, respectively.
In 1979, Tom Truscott and Steve Bellovin, graduate students
for Duke University, created an early predecessor to dial-up Internet access
called the USENET. The USENET was a UNIX based system that used a dial-up
connection to transfer data through telephone modems.[1] Dial-up Internet has
been around since the 1980s via public providers such as NSFNET-linked
universities and was first offered commercially in July 1992 by Sprint.[2]
Despite losing ground to broadband since the mid-2000s, dial-up may still be used
where other forms are not available or the cost is too high, such as in some
rural or remote areas.
Dialup internet service is a service that allows
connectivity to the internet through a standard telephone line. By connecting
the telephone line to the modem in your computer and inserting the other end
into the phone jack, and configuring the computer to dial a specific number
provided by your internet service provider (ISP) you are able to access the
internet on your computer.
Dial up internet service is provided through several ISP.
The majority of internet service providers give you a set of telephone numbers
either national or local that allows you to dial into a network that feeds into
the internet. This allows you to receive and send email, search the World Wide
Web, participate in chat rooms and plenty of other features the web has to
offer.
In order to get a dial up internet service a person must
definitely have a computer and even more important a modem. There are different
types of modems, and most of them are inexpensive to purchase. You can have an
internal modem installed in a free slot of your computer, or you can have an
external modem that's hooked up to the computer through cables. A telephone
line is linked to the modem.
The modem whether external or internal is controlled by
software on the computer. With Microsoft Windows operating system that software
is the Network Connection utility which allows you to connect to the internet.
How? In the Network Connection utility you have to set up ISP profile so that
the modem knows what phone number to dial so that you can connect to the internet.
Once you have found an internet service provider and joined
you must choose a password and username. Why? When the modem dials the phone
number you are given by your ISP, a connection is made, and then information is
swap between the modem and the remote server. A remote server is the computer
and related software that is established to handle users who want to access a
network remotely. The username and password you choose for the modem allows
access to the dial up gateway to the internet. The gateway to the internet is a
network that allows entry into another network.
If you are looking for an inexpensive internet service dial
up is the way to go. Not only is it the cheapest but also the slowest type of
access you can get. Since the bandwidth is limited it will take some time for
the modem to send and receive information. It will be slow loading web pages,
listening to music and watching videos online. There are all kinds of software
available that can help speed up your dial up internet.
With dial up internet you cannot use the phone and search
the web at the same time. How come? Remember while one end of the telephone is
linked to the modem the other end is in the phone outlet. There are internet
services available that allows you to use the phone at the same time and be
online.
So as you can see dial up internet has its pros and its
cons. If you are looking for a inexpensive internet service and don't mind not
being able to talk on the phone and use the web at the same time then dial up
is definitely for you!
Dialup
modem
News wire services in the 1920s used multiplex devices that
satisfied the definition of a modem. However, the modem function was incidental
to the multiplexing function, so they are not commonly included in the history
of modems. Modems grew out of the need to connect teleprinters over ordinary
phone lines instead of the more expensive leased lines which had previously
been used for current loop–based teleprinters and automated telegraphs.
In 1941, the Allies developed a voice encryption system called
SIGSALY which used a vocoder to digitize speech, then encrypted the speech with
one-time pad and encoded the digital data as tones using frequency shift
keying.
Mass-produced modems in the United States began as part of
the SAGE air-defense system in 1958 (the year the word modem was first
used[1]), connecting terminals at various airbases, radar sites, and
command-and-control centers to the SAGE director centers scattered around the
United States and Canada. SAGE modems were described by AT&T's Bell Labs as
conforming to their newly published Bell 101 dataset standard. While they ran
on dedicated telephone lines, the devices at each end were no different from
commercial acoustically coupled Bell 101, 110 baud modems.
The 201A and 201B Data-Phones were synchronous modems using
two-bit-per-baud phase-shift keying (PSK). The 201A operated half-duplex at
2,000 bit/s over normal phone lines, while the 201B provided full duplex 2,400
bit/s service on four-wire leased lines, the send and receive channels each
running on their own set of two wires.
The famous Bell 103A dataset standard was also introduced by
AT&T in 1962. It provided full-duplex service at 300 bit/s over normal
phone lines. Frequency-shift keying was used, with the call originator
transmitting at 1,070 or 1,270 Hz and the answering modem transmitting at 2,025
or 2,225 Hz. The readily available 103A2 gave an important boost to the use of
remote low-speed terminals such as the Teletype Model 33 ASR and KSR, and the
IBM 2741. AT&T reduced modem costs by introducing the originate-only 113D
and the answer-only 113B/C modems.
