ADSL and SDSL are relatively new access technologies, based on the
use of unused communications bandwidth in the wire "local loop"
used to provide basic analog telephone service. DSL offers possible
data rates from several hundred kbps up to the low Mbps range.
One difference between DSL services and other types is that, due
to the way commercial access to telephone exchange DSL equipment is
structured, ISPs can charge a single monthly fee including both
"Basic Access" and Internet charges.
