Dial up

Since early 1990s dial up connection system has been used for internet access. This involves use of a computer connected to a telephone line through a modem at the user end, and a modem connected to the telephone line at the dial up isp’s end. The user dials into the internet service provider’s node; on achieving this modem-to-modem link, the call gets routed to the internet. The user can, thereafter, search the web sites and download (or upload) as desired. Modem in this case will modulate analog carrier signal to encode digital information for sending over the telephone lines.

Dial up requires several seconds to establish contact and to perform a handshake – a protocol – before data transfer can take place. Data transfer rate in a dialup connection is generally of the order of about 50 kbps - quite slow by today’s broadband standards. But in spite of the handicap of slowness, dial up internet usage is still commonly found in many areas throughout the world.

In spite of the desire of all people to have access to faster internet service whether for business or pleasure, internet dialup system continues due to various reasons. Firstly, it probably involves the least investment from the user for many areas. Secondly, since telephones are available throughout the world and internet dial up does not require any modification of the existing telephone network, dialup internet access could be available anywhere in the world. Thirdly, and most importantly, in many areas it may not be possible to have access to a high speed internet connection due to low population density, poor demand and poor infrastructure. Many dialup ISPs provide free dial up connection. Such free internet dial up can still be quite costly since the telephone call charges have to be paid for the time the internet connection is made. Free dial up internet services are widely advertised by free dialup ISPs.

There is, however, an intermediate solution to this handicap of dial up system. High speed dial up is a new system which speeds up the internet access significantly. In this system, the dial up internet provider interposes an acceleration server at his end at which the user’s connection terminates. Instead of establishing a direct data transfer between the user and the web-server from where the user has to obtain information, the acceleration server collects the information at high speed from the web-server on user’s behalf, so to say, and passes on to the user. High speed dialup cuts down the time for searching web addresses and downloading information by as much as 50 % in many cases.