| Abstract: | We consider a system where the superposition of two heterogeneous Poisson traffic streams is offered to an integrated network link in synchronous transfer mode, where one stream follows the blocked-and-cleared mode (‘loss’ mode) and the other can wait (finitely) if bandwidth is not available for connection at the time of arrival (‘hold’ mode). We assume that each stream has different bandwidth requirements per call. A reservation scheme, called anticipated-release policy, is introduced where an arrival is accepted into a waiting room only if the amount of time this customer is expected to wait is within acceptable limits. For such a loss/hold system, we provide analytical performance models for exponential service time distributions for both streams as well as for the non-exponential service time distribution case for the traffic stream in ‘hold’ mode. We also present a method on how to model the waiting time distribution of the traffic stream with ‘hold’ mode. From numerical studies, we observe that blocking can be reduced considerably for both services just by introducing a small waiting room for one traffic class compared to ‘loss’ mode for both traffic classes. Furthermore, this holds true for the case when a maximum tolerable time limit is imposed on the waiting. Finally, our results indicate that this loss/hold scenario with limited waiting room appears to be virtually insensitive to the service time distribution of the ‘hold’ mode traffic. |
