DSL transfers data digitally using standard telephone system copper wires, and does so much faster than traditional analog "dial-up" modem connections. It is not the same as ISDN (which is digital) but similar in the fact that they both use telephone lines (POTS). The advantage of xDSL is that it can reach much higher speeds than ISDN or dial-up, typically 384kbps to 6Mbps.

The primary advantages of DSL over dial-up are:

• High speed uploads and downloads (from 5 to 100 times faster)
• Always-on connection: no need to "dial-up"
• Use your phone at the same time - it does not tie up the phone line

• More expensive (typically $40/month)
• Limited range: ADSL is typically limited to a distance of approximately 15,000ft. from your telephone company's central office (CO).
• Limited availability: DSL is not available in all markets/areas
• An always-on connection makes you more vulnerable to security holes and hackers but you can protect yourself with software or hardware firewalls.

If you have DSL and would like to test your connection's throughput (speed), visit the DSL Reports speed test center.

DSL related Acronym List:

ADSL	Asymmetric Digital Subscriber Line
ATM	Asynchronous Transfer Mode
bps	Bits Per Second
CO	Central Office
DSLAM	Digital Subscriber Line Access Multiplexer
ISP	Internet Service Provider
Kbps	Kilobits Per Second
LAN	Local Area Network
Mbps	Megabits Per Second
NIC	Network Interface Card
POTS	Plain Old Telephone Service
PPP	Point to Point Protocol
SDSL	Symmetric Digital Subscriber Line
VDSL	Very high bit-rate Digital Subscriber Line

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