The M/G/l/∞ queues with instantaneous Bernoulli feedback have been studied by Takacs, Disney and others. This work is motivated by the fact that most queueing systems have finite waiting room for the practical applications.
In this paper we investigate the M/G/l queues with instantaneous Bernoulli feedback for the case of finite waiting room. First, we investigate the stationary distributions of the number of customers in the system, at time t, departure epochs, arrival epochs, output epochs and feedback epochs. Finally, we apply the general results to the M/M/l/K queues with instantaneous Bernoulli feedback.