ABSTRACT
A protocol stack is a set of layers that incorporates standards of one system or another at each layer. Asynchronous transfer mode (ATM) is an open standard based on the documentation available from the International telecommunications union-T and the ATM forum. ATM protocol stack is for communications over a high-speed network where information is sent in an unchannelized fashion through cells. The physical layer in the ATM protocol stack sends and receives cells. However, these cells are actually processed by the ATM layer. Support for higher layer services such as circuit emulation, frame relay, internetwork protocol and switched multi-megabit services is provided by the ATM adaptation layer. The physical layer of the ATM protocol architecture has a different implementation based on different media types. On the transmission side of the network the transmission convergence sub-layer is responsible for loading the ATM cells into the physical transport transmission frame.
