Survivability: Wavelength Recovery for Node and Link Failure in All Optical Networks

Survivability is a critical network design issue in todaypsilas all optical networks. Its objective is to restore the traffic affected by a failure at the network level with little or minimal loss and delay. In a multilayer network environment, this problem becomes more complex since a physical failure may generate multiple failures in different network layers. Optical networks (e.g. SDH) have been studied for several years and protection technique standards for such networks have been developed. Multi-layer survivability techniques promise to overcome this problem by integrating the survivability techniques provided in the different network layers. This article takes a look at the techniques used to achieve survivability in traditional optical networks, and to a certain extent how those techniques are extendable to present day optical burst switching (OBS). It further proposes a survivability implementation strategy for a mesh topology network.