Assessment and Open-Issues of the Load-Balanced Switching Architecture

High packet switching performance and the potential scalability to a large number of input/output ports, under the admissible traffic assumption, have made Birkhoff-von Neumann load-balanced switch one of the most attractive and promising switch architecture. The focus of this study is on the construction of large number of input/output ports load-balanced switch with very high transmission rate, which is robust enough to better support ever-growing Internet traffic. In this paper, we analyze the state-of-the-art of load-balanced switching while assessing key open issues. We present solutions to some existing problems, specifically to cells re-sequencing in the central and output stages, and the impact on the overall system scalability. A set of new and more complex load-balanced switch architectures will be described in details. This work presents a study of switching behavior with input arrival of variable size packets. The research shows that under certain circumstances the original load-balanced switch will face a critical problem of cells drop in the middle stage buffers, which can lead to unpredictable behavior of the system due to complex variable size packet reassembly at the output stage buffers.