Digital Subscriber Line (DSL)

DSL is a developing WAN technology that exploits unused frequencies on copper telephone lines to transmit traffic typically at multi-megabit speeds. DSL can allow voice and high speed data to be sent over the same line. Because the service is 'always available' end-users don't need to dial in or wait for call set-up.

xDSL indicates the entire range of DSL technologies, including:

• SDSL : Symmetric Digital Subscriber Line = Same speeds for download and upload
• ADSL : Aysymmetric Digital Subscriber Line = Higher download speed, lower upload speed (most common)