<Tr> <Td> </Td> <Td> This article's tone or style may not reflect the encyclopedic tone used on Wikipedia . See Wikipedia's guide to writing better articles for suggestions . (October 2012) (Learn how and when to remove this template message) </Td> </Tr> <Table> <Tr> <Td> </Td> <Td> This article may be in need of reorganization to comply with Wikipedia's layout guidelines . Please help by editing the article to make improvements to the overall structure . (March 2017) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This article may be in need of reorganization to comply with Wikipedia's layout guidelines . Please help by editing the article to make improvements to the overall structure . (March 2017) (Learn how and when to remove this template message) </Td> </Tr> <P> 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". ATM was developed to meet the needs of the Broadband Integrated Services Digital Network, as defined in the late 1980s, 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 . 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 . </P>

Atm is a wan technology that functions in the data link layer