Abstract
In this paper we describe a model for systems in which the customers usually reserve the required facilities in advance. The model has been developed for a communication network which provides visual conferencing services. We concentrate upon a network with a single pair of cities. Each customer calls the reservation office and specifies the desired day, starting time and holding time for his conference. A scheduler either satisfies the customer's request or offers him up to two alternatives which he may or may not accept. Various performance indices of the system, such as the proportion of lost customers, the proportion of rescheduled customers and the facilities' occupancy rate, are derived. Numerical examples and applications are discussed.