Analysis of shared buffer multistage networks with hot spot

Multistage interconnection networks based on shared buffering are known to have better performance and buffer utilization than input or output buffered switches. Shared buffer switches do not suffer from head of line blocking which is a common problem in simple input buffering. Shared buffer switches have previously been studied under uniform and unbalanced traffic patterns. However, due to the complexity of the model, the performance of such a network, in the presence of a single hot spot, has not been fully explored. A hot spot arises when one of the outputs of the network becomes very popular. We develop a model for a multistage interconnection network constructed from shared buffer switching elements and operating under a hot spot traffic pattern. The model is validated by comparison with simulation results. The model is used to study the network performance in terms of the throughput, packet delay, packet loss probability and the optimal buffer utilization, Numerical results show that, in the presence of hot spot traffic, shared buffer switches degrade more significantly than switches with dedicated input and/or output buffers