An exponential two-phase queueing system where calls are erased

The well-known results for a two-node exponential service network are extended to the case where calls may be erased. An infinite capacity accumulator is available in the first node of the network. For node interface disciplines where internal losses of calls or interlocks of the first node are possible, ergodicity conditions and an algorithm for determining the stationary probabilities of the number of calls in the network are provided.