• noun method of transferring data very rapidly, at up to 155 Mbps, across an ISDN link or network
  • noun a CCITT and ANSI standard defining cell relay transmission
  • noun electronic machine in a bank that dispenses cash when you insert a magnetic card.


  • Abbreviation of asynchronous transfer mode. In networks, a connection-oriented communications protocol. ATM carries data, audio, video, or any other information which can be digitally encoded, in packets of a fixed size. Each packet, or cell, consists of 53 bytes, 48 of which are payload, and 5 of which are overhead. Cells can be transferred between nodes at speeds ranging from 1.5 Mbps, to over 10 Gbps. In addition, ATM has quality of service standards which insure a reliable level of performance, and can appropriate unused bandwidth for other communications. For example, a videoconferencing circuit can be used for transmission of data during its idle periods. Also called ATM protocol.
  • Abbreviation of automated teller machine, or automatic teller machine.


  • acronym forasynchronous transmission mode


  • acronym forair traffic management