Abstract: Continuously growing needs for distributed applications that transmit massive amount of data has led to the emergence of high-speed networks that require broadband and multimedia capabilities. Such networks are supposed to have the ability to handle heterogeneous traffic and to manage large span of resources and services effectively. In this paper, a single server G/D/1 queuing system with infinite buffer is simulated with the consideration of three input traffic sources: exponential, weibull, and normal distributions. The upper bounds on buffer size are evaluated for the given distributions.