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)
IPCCTV White Paper
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.