The effects of user behavior and Internet provider policy on the accessibility of SezamPro on-line system

We present a model of an online system that includes user population, a number of dial-in lines, and specific waiting subsystem. According to this model we perform simulations in order to show the effects of various user behaviors and provider policy on the accessibility of the system. In addition to experiments with assumed values of parameters, we also determine realistic values based on data recorded on the SezamPro, the largest online system in Yugoslavia.