Modeling of computer networks for performance evaluation and control under nonstationary conditions

Three distinct approaches for modeling computer networks under nonstationary conditions are presented. The first approach uses a queuing-theoretic formulation to develop numerical techniques for determining the nonstationary queue dynamics and for estimating the settling time for the queue. In the second approach, discrete-event simulation techniques are used for the evaluation of network performance during nonstationary periods. The third approach develops a nonlinear state model for representing the dynamics of the packet queues at the various transmission links of the network and establishes a framework for formulating optimal control problems for designing routing and flow control strategies that ensure optimal network performance under both transient and steady-state conditions