Call admission control and resource utilization in ATM networks: a new improvement strategy

Congestion and admission control are two of the most widely investigated problems which must be faced in ATM. The FBR (fast buffer reservation), i.e. a virtual circuit acceptance algorithm proposed by Turner (1992), based on the excess probability criterion (EPC), seems to be a complete approach for bandwidth management. It will constitute the starting point of the new admission and congestion control strategy proposed in this paper. FBR cannot use the EPC algorithm because of lock out problems; moreover, the utilization of the FBR buffer should be improved. Therefore, a new mechanism for accepting bursts to the buffer is proposed together with a new kind of service at the buffer exit. Merged with EPC this mechanism will become simple, economically implementable, it will offer the required flexibility and robustness, as well as ease of control. In addition, it will preserve burst integrity and present high burst-served to burst-sent ratio. Finally, a low burst loss, determined only by burst refusal at the buffer entry, will be obtained.