Free DSL Search Glossary - Technical Terms De-Mystified

 

ADSL (Asymmetrical Digital Subscriber Line) - Commonly called DSL. Technology and equipment that allow high-speed communication across normal twisted pair copper wiring. This may also include video signals. ADSL can transmit at high rates of speed both upstream and downstream. The downstream speed is typically faster than the upstream speed...hence the term "asymmetrical" ( i.e.; 1.5Mbps upstream / 768 Kbps downstream). See also DSL.

Bandwidth - Also sometimes referred to as "capacity". The volume, or amount of data that an Internet connection (modem or transmission line) can handle. The data is typically measured in bits per second (bps).
Certain technologies, such as DSL or high speed cable internet, may increase the volume of data that can be transmitted to or received from the Internet.

Broadband - A single, multi channel cable or wire that is used to carry a large volume of data at high speeds. Examples of broadband connections include DSL modems, which use existing, twisted copper phone lines and cable modems, which use existing cable television connections.

Central Office (CO) - A telecommunications term, referring to the physical location of the local telephone company's building where home and business subscriber lines are connected to the rest of the network. For the purposes of Internet access, the central office switching equipment receives data transmission from a customer's location, then threads them into the Internet over the telephone companies’ or third party networks.

DSL (Digital Subscriber Line) - a kind of modem technology that allows your existing phone line to be used as a three-channel data delivery system. The first channel transmits voice services, so normal phone and fax usage can continue. The second channel transmits data downstream at high speeds, and the third bi-directional channel transmits data upstream at a slower rate of speed. The downstream and upstream channels carry information to and from the Internet. A phone or fax call in progress on the first channel will not be affected by your online activity. A DSL modem provides a dedicated or “always on” connection, eliminating the need to dial-up for access to the Internet.

Modem - Acronym for modulator/demodulator. A device that connects your computer to the Internet, over a phone line. Modems work at different speeds; the faster the speed, the faster that information flows to (and from) your computer. Although you can access the Internet with a modem of any speed, it is desirable to go as fast as possible. A modem's speed is measured in bits per second, or bps.

SDSL (Symmetric Digital Subscriber Line) - A type of DSL that sends digital pulses in the high-frequency area of telephone wires. SDSL cannot operate simultaneously with voice connections over the same wires. SDSL requires a special SDSL modem. SDSL is called symmetrical because it supports the same data rates for upstream and downstream traffic (i.e.; 1.5Mbps upstream / 1.5 Mbps downstream)