Congestion Formulas for a Heterogeneous Server Loss System with Random Selection Discipline

A heterogeneous server loss model which has found considerable use in modeling faulty trunk circuits is studied. The server selection discipline is random, service time distributions are general and the arrival process is Poisson. Results obtained include closed form expressions for the server occupancies and group blocking which involve only the well studied and tabulated Eriang Loss Function. The results are useful for the insight they yield about system behavior, as well as the ease with which numerical results can be obtained.