Asynchronous Transfer Mode (ATM)
1988 - initiated as part of ISDN by Consultative Committee for International Telegraph and Telephone (CCITT)
1991 - ATM Forum to reach agreement on interfaces in North America. Participants include vendors, carriers, and users.
ATM is cell switched, connection oriented, full duplex, point-to-point protocol using asynchronous time division multiplexing (TDM) to control flow
The 53 Byte fixed length cells consist of 5 Byte header and 48 Byte payload (5X8 + 48X8 = 424 bit)
Header contains address information in form of a virtual circuit connection (VC)
PVC - permanent virtual circuit for dedicated bandwidth
SVC - switched virtual circuit sets up circuit as needed by the application