The physical infrastructure supporting data communications has improved its ability to transmit data quickly with advances such as optical fibers. As this physical capacity increases, there is a need to utilize effectively the bandwidth to carry a variety of traffic (voice, video, data) in an efficient manner. Traditionally, circuit switching is used to support the real-time delivery needed for voice and video. Packet switching is used to support intermittently heavy data traffic. Asynchronous Transfer Mode (ATM) has emerged as a technology that efficiently utilizes the bandwidth while carrying one or more traffic types. ATM is a high-speed packet switching technology that is capable of supporting both real-time voice and video and the kind of data traffic that has peaks and plateaus in its transmission.

ATM uses fixed size packets (called cells) to reduce processing and switching delays. The cell size is kept small, at...