ATM has now been widely accepted as the leading contender for the implementation of broadband communications networks (Brinkmann, Lavrijsen, Louis, et al, 1995) ATM networks are no longer restricted to research laboratories, and commercial products such as switches and interfaces manufactured by well known computer and communications companies have started to appear in the market place. The main advantage seen in ATM over other broadband networking technologies such as Synchronous Transfer Mode (STM) is its ability to transmit a wide variety of traffic types, including voice, data and video efficiently and seemlessly.