A hybrid model and measurement based connection admission control and bandwidth allocation scheme for ATM networks

We extend the earlier work of Ramamurthy and Ren (see IEEE INFOCOM'97, 1997) and develop a dynamic connection admission control (CAC) scheme that supports cell loss requirements. The CAC algorithm explicitly computes the equivalent bandwidth required to support each class of connections based on on-line observations of aggregate traffic statistics as well as the declared parameters. We use Gaussian and diffusion approximations to characterize the aggregate traffic stream. Through careful analysis and collection of statistics, we derive simple closed-form formulas to estimate the equivalent bandwidth in real time. We validate the proposed algorithms for various VBR traffic profiles and show that the system utilization can be substantially improved by appropriately combining traffic characteristics deduced from the declared parameters and traffic measurements.