Abstract: A cell or packet-based Connection Admission Control (CAC) solution is provided for transmitting Protocol Data Units (PDU) such as Asynchronous Transfer Mode (ATM) user cells or Internet Protocol integrated and differentiated service packets. The CAC method and apparatus allocate network resources including user cell/packet transferring bandwidth in the channel/connection/flow set-up phase. The calculation of Effective Bandwidth is implemented in hardware using an additive-Fractal and measurement-based approach to shorten the processing time and to increase overall system reliability and efficiency.