A simulation study of the performance of the extra-stage cube and the augmented-shuffle exchange networks under faults

Abstract

In this paper, we conducted a simulation study to compare the performance of the Extra-Stage Cube (ESC) and the Augmented-Shuffle Exchange (ASE) networks in the presence of multiple link failures. The main objective of this study is gain an insight as to which of these two networks can better support graceful degradation under varying network loads and link failure rates. To achieve this task, three performance metrics are introduced, these are throughput, Message-Delivery ratio, and Average Delay Per Message and three simulation experiments using the simulation package COMNET II.5 are designed.The simulation results indicate that with respect to the three performance metrics, the ESC network outperforms the ASE for network size N≥32 and link MTTF=0.75 hours. However, when the link MTTF=0.12 hours, the ASE network outperforms the ESC network for N<64. In both cases, the ESC network outperforms the ASE network when N=64. This result appears to be directly related to the link complexities of the two networks. For large networks, the link complexity of the ASE is much larger than that of the ESC network and accounts for its poorer performance when N<32.