A hybrid ATM connection admission control scheme based on on-line measurements and user traffic descriptors

Connection admission control (CAC) is a preventive congestion control mechanism and it is essential for providing quality of service (QoS) requirements for calls established over ATM. The strategies for CAC in an ATM network can be classified into two categories: measurement-based CAC and traffic descriptor-based CAC. Both categories have their advantages and disadvantages. This paper proposes a simple CAC algorithm which utilizes both traffic descriptors and parameters that can be reliably and accurately derived from on-line measurements. This hybrid CAC algorithm avoids the disadvantage of traffic descriptor based CAC in which some traffic parameters can not be tightly characterized by sources and the disadvantage of measurement-based approach in which some measurements are not reliable and/or time-consuming. CAC decision can be made easily in our algorithm. Simulation studies are presented which are indicative of the good performance of our algorithm.