Asynchronous Transfer Mode (ATM)

ATM does not relate in any way to asynchronous dial-up connections. Rather, it refers to the
transmission of fixed-length cells and the transport of data, voice, and video services. The majority
of the public telephone network has already converted to this technology for the aggregation of
phone lines. Cells are fixed in length, and therefore latency and delay can be determined and controlled
accurately.
ATM is rarely used as a remote access technology in the context applied to the exam, and it
would be best to think of it as a potential replacement for Frame Relay installations. Typically,
residential ATM installations appear in the form of DSL—ATM being the underlying Data Link
(layer 2) technology.