Fast Detection of Alternative Route under Unknown Failure on SDN Network

Fast recovery from failures in a network is a serious challenge. Failures are sometimes not detected because of the management system's own failure or misconfiguration by human error. Such failures are called silent failures. Many researchers have studied silent failures, and much attention has been paid to developing a management system that detects silent failures more accurately. However, these silent failure detection methods require a large amount of information. Therefore, for fast recovery, a failure point should not be localized with a long period first. Although using an alternative route is effective, in this case, the alternative route that avoids all suspicious nodes and links on a degraded route may not satisfy an allowable delay. In this paper, we present a method to quickly configure an alternative route within the flow allowable delay. In this method, suspicious nodes and links are pruned gradually until an alternative route is found that satisfies the allowable delay. To realize the pruning and the alternative route configuration, we use Software- Defined Networking(SDN) architecture. Our simulation evaluation in various topologies and traffic conditions shows the advantage of the method and the conditions in which it is most effective.