WHAT IS ADSL?
At the simplest level, ADSL is a high-speed replacement for your modem or ISDN adapter that allows you to access the Internet faster. The following diagram shows the maximum speeds attainable..

What does ADSL mean?
ADSL stands for Asymmetrical Digital Subscriber Line - it is the transmission technique used on the line from your modem to your service provider.

Asymmetrical: The speed of transmission is not the same in both directions. The downstream (from network to consumer) speed can be more than ten times as fast as upstream (from consumer to network). This coincides nicely with the requirements for Internet access where a single mouse click (therefore a small amount of data sent by the consumer) can result in the receipt of a large amount of data from the Internet.

Digital: ADSL modems operate on a bit stream, and are intended for carrying digital information between digital equipment such as PCs. In this respect they are no different from conventional modems.

Subscriber Line: ADSL itself only operates over the subscriber's normal telephone line to the local exchange. The telephone line can continue to be used for voice calls through the use of devices called 'splitters' that separate the data and voice on the line. Beyond the point at which the subscriber's line is terminated in the exchange, other technologies are responsible for the data transmission.

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