DSL DSL (Digital Subscriber Line) is a set of standards for broadband network connectivity over normal telephone lines.
ADSL
ADSL (Asymmetric DSL) is a type of DSL where the upstream and downstream bandwidth are assigned different amounts of bandwidth. Typical configurations today are 2Mb downstream and 128Kb upstream.
Downstream refers to data which you are downloading across the network to your local systems. Upstream refers to data you are sending from your local systems across the network.
ADSL is the most common flavor of DSL.
VDSL
VDSL (Very high bit-rate DSL) is an asymmetric version of DSL which operates at very high speeds.
VDSL operates at downstream speeds up to 55Mbps, but only at a distance of up to 1000 feet from the Central Office (CO).
At longer distances, VDSL transmission rates drop dramatically.
xDSL xDSL is a generic term that refers to any type of DSL: ADSL, HDSL, IDSL, RADSL, SDSL, VDSL, DSL Lite, G.SHDSL, etc...
DSLAM
A DSL circuit exists between the DSL modem on the customer premesis and a DSLAM (Digital Subscriber Line Access Multiplier). The DSLAM is usually located in the telco Central Office (CO).
One DSLAM can terminate several hundred DSL connections.
Linear Mode
