AN ATM BUFFER CONTROLLER AND A METHOD THEREOF

An ATM (asynchronous transfer mode) buffer controller and an ATM buffer control method, which maintains a high level of the quality of service of ATM traffic independent of whether shaping is required or not, is realized. Traffic not requiring shaping is queued in a dedicated output queue of every ATM service category and is output in the order of each priority via the control of fixed priority. In the meantime, traffic requiring shaping is queued in any of n pieces of shapers and shaping processing is applied to the traffic. All shapers can select a suitable one of five round robin control sections by the class of the traffic and hereby, the optimum control of the priority of the output of the corresponding ATM traffic is executed.