DSL Glossary of Terms

ADSL (Asynchronous Digital Subscriber Line)
DSL connection where the download speeds exceed the upload speeds

Bit
A single unit of data that is either a 1 or a 0. Usually measured in terms of kilobits (approximately 1,000 bits) or megabits (approximately 1,000,000 bits).

Broadband
Defined by the FCC as an Internet connection that exceeds 200 kbps data transmission in at least one direction.

Central Office
Location where the phone lines in a geographic area are aggregated.

Dedicated Connection
Always on connection that allows Internet access 24 hours a day.

Downstream
Flow of information into your computer.

DSL (Digital Subscriber Line)
High-speed dedicated Internet connection that uses standard copper telephone lines to transfer data.

DSLAM
Device located in the central office where multiple DSL lines are aggregated into one line.

Internet Service Provider
A company that provided Internet Access to its customers.

Kbps
Kilobits per second.

Mbps
Megabits per second.

Prequalification
Test performed to determine how far a customer is from a central office and what types of DSL connection are available to them.

SDSL (Synchronous Digital Subscriber Line)
DSL connection where the download and upload speeds are the same.

Upstream
Flow of information out of your computer.

xDSL
Generic term that refers to all types of DSL connections.