ATM

Asynchronous Transfer Mode

Asynchronous transfer mode (ATM) is, according to the ATM Forum, "a telecommunications concept defined by ANSI and ITU (formerly CCITT) standards for carriage of a complete range of user traffic, including voice, data, and video signals".[1] ATM was developed to meet the needs of the Broadband Integrated Services Digital Network, as defined in the late 1980s,[2] and designed to integrate telecommunication networks. Additionally, It was designed for networks that must handle both traditional high-throughput data traffic (e.g., file transfers), and real-time, low-latency content such as voice and video. The reference model for ATM approximately maps to the three lowest layers of the ISO-OSI reference model: network layer, data link layer, and physical layer.[3] ATM is a core protocol used over the SONET/SDH backbone of the public switched telephone network (PSTN) and Integrated Services Digital Network (ISDN), but its use is declining in favour of all IP.\