非同步傳輸模式網路之存活性研究之虛擬路徑重建問題

Abstract

Self-healing is a key issue in developing reliable and efficient Asynchronous Transfer Mode(ATM)networks, because it can provide the network with the failure recovery ability and reduce the economic and social damage caused by network failure. In the past, most of the self-healing algorithms proposed in the literature emphasize on how to achieve 100% fault restoration rate and leave the bandwidth utilization as a minor issue. In this paper, we propose two new self-healing algorithms for mesh typed ATM networks to improve the bandwidth utilization while keeping the restoration rate as high as possible. Both of these two algorithms combine restoration technique with dynamic VP routing strategy to improve the network resource utilization. The main difference between these two algorithms is the underlying VP bandwidth allocation mechanism. The performance of theses two algorithms are evaluated through simulations and are compared to one existing algorithm. With the combination of self-healing and dynamic routing, the proposed two algorithms yield near zero blocking probability while maintaining reasonable restoration rate. A new performance metric, referred to as restoration reward, is also proposed to evaluate these two algorithms to show how much reward can be restored during a network failure.