A performance modeling scheme for multistage switch networks with phase-type and bursty traffic

Existing analytical methods to model multistage switch networks cannot be applied to the performance modeling of switch networks with phase-type and bursty traffic because of the problem of state-space explosion and unrealistic assumptions, e.g., uniform traffic and independent destination (UTID). This paper presents an approximate scheme to model and analyze such networks. First, a traffic aggregation technique is proposed to deal with phase-type and bursty traffic, including splitting and merging. For the aggregation of two bursty traffic, a closed-form solution is obtained for buffer state probabilities. For the aggregation of more bursty traffic, a recursive algorithm is derived in terms of the buffer size and number of inputs of a switch. Second, a switch decomposition technique is developed, by which the crossbar of a switch is decomposed from its preceding and succeeding buffers. In this way, a switch network of N inputs and outputs is converted to N tandem queues, for which the performance can be easily evaluated. Our extensive numerical and simulation examples have shown that the proposed scheme achieves satisfied accuracy and computational efficiency.