Szukana fraza: [Abstract = "To facilitate the investigation of the system we use a generalized phase\-type service time distribution. The criterion of ergodicity for a multi\-dimensional Markov chain describing the behavior of the system and the algorithm for computation of its steady\-state distribution are outlined. Some key performance measures are calculated. The Laplace\-Stieltjes transforms of the sojourn and waiting time distributions of priority and non\-priority customers are derived. A numerical example illustrating the importance of taking into account the correlation in the arrival process is presented."]