ADSL stands for Asymmetrical Digital Subscriber Line - it is the transmission technique used on the line from your modem (CPE) to your service provider (NT).
Asymmetrical: The speed of transmission is not the same in both directions. The downstream (from network to consumer) speed can be as fast as ten times of upstream (from consumer to network). This coincides nicely with the requirements of Internet access for the large amount of data down load.
Digital: ADSL modems (also known as CPE) 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 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 device called 'splitters' that separate the data and voice on the telephone line.
Asymmetrical: The speed of transmission is not the same in both directions. The downstream (from network to consumer) speed can be as fast as ten times of upstream (from consumer to network). This coincides nicely with the requirements of Internet access for the large amount of data down load.