Regional fault tolerant recovery mechanism for multilayer networks

Abstract

With the multi-rate transmission and variable bandwidth switching technology, the Elastic Optical Networks (EONs) have many advantages to satisfy current network traffic. Compared with the traditional optical network, the EONs improve the spectrum utilization and increase the network capacity. So the EONs gradually become the key point of next generation optical transport networks. Obviously, the restoration mechanism in EONs has become thefocus of network operators' attention. This paper presents a dynamic restoration scheme based on software defined network (SDN) framework and an improved regional fault-tolerant routing and spectrum allocation algorithm (RSA). Using the SDN framework, we can greatly reduce recovery time and avoid configuration contentions. On this basis, we introduce the improved regional fault-tolerant RSA algorithm. The proposed RSA algorithm can decrease restoration blocking probability and relief effects caused by regional failures. The performance of the proposed dynamic restoration is evaluated in terms of restoration blocking probability and recovery time under different network loads, and compared against other schemes.