Asymmetric digital subscriber line (ADSL) is a type of DSL, a data communications expertise that allows quicker data transmission in excess of copper telephone lines than a usual voiceband modem can offer. It does this by using the frequencies which are not used by our normal voice telephone call. [1] A splitter - or else microfilter - enables a single telephone connection to be used for both ADSL service as well as voice calls at the similar time. ADSL can only be dispersed over short distances from the central office, normally not more than 4 kilometers (2 mi),[2] but has been known to go beyond 8 kilometers (5 mi) if the formerly laid wire gauge allows for beyond distribution.

At the telephone exchange the line normally comes to an end at a DSLAM where one more frequency splitter divides the voice band signal for the usual phone network. Data carried by the ADSL is normally routed above the telephone company's data network as well as finally reaches a conformist internet network.