Fast time-dependent evaluation of multi-service networks1

We present a numerical-analytical method to evaluate multi-service networks with adaptive routing, scheduling and admission controls. We apply our method to connection-oriented networks supporting different types of real-time connections. The network dynamics is described by difference equations which can be solved for both transient and steady-state performances. Results indicate that our method is computationally much cheaper than discrete-event simulation, and yields accurate performance measures. Connection routing algorithms are usually evaluated individually in terms of steady-state performance measures. In this paper, we also use our time-dependent evaluation method to compare several connection routing schemes in terms of instantaneous measures. Our results show that a routing scheme which defines the cost of a path as the sum of measured link utilizations yields more stable behavior and lower connection blocking probability over a wide range of workload parameters and network configurations than other traditional schemes.