Performance evaluation of VSQ: a fair MAC scheme for packet ring networks

Packet ring networks are increasingly being used to support data services in metropolitan areas. The IEEE 802.17 resilient packet ring (RPR) standard is a new technology for metro packet rings. However, there are some performance deficiencies associated with RPR, such as large access delay, throughput loss and slow convergence. In our previous work, we proposed a fair medium access control (MAC) scheme called virtual source queuing (VSQ) for packet ring networks. We also designed an effective congestion control scheme called one-hop-backpressure (OHB) to ensure lossless transit paths for VSQ. OHB exploits the source information and implicitly control the input rate of the sources that send excessive traffic. In this paper, we provide detailed performance evaluation of VSQ in comparison with various MAC schemes. Our simulation and analysis results demonstrate that VSQ requires less transit buffer occupancy and variance to ensure lossless transit paths than RPR does. We also conduct complexity comparisons among different MAC schemes. The comparisons show that VSQ is a simple and efficient MAC scheme for metro packet ring networks