Practical issues for the implementation of survivability and recovery techniques in optical networks

Failures in optical networks are inevitable. They may occur during work being done for the maintenance of other infrastructures, or on a larger scale as the result of an attack or large-scale disaster. As a result, service availability, an important aspect of Quality of Service (QoS), is often degraded. Appropriate fault recovery techniques are thus crucial to meet the requirements set by the Service Level Agreements (SLAs) between carriers and their customers.In this paper, we focus on practical issues related to the deployment of fault recovery mechanisms in commercial optical networks. In particular, we outline the most important functionalities that, to the best of our knowledge, need to be implemented, as well as discuss the related problems making deployment of fault recovery mechanisms difficult. Investigated topics include fault recovery challenges (fault detection, location, and recovery), multiple failures recovery, as well as application of reliability mechanisms in Elastic Optical Networks, and in multiprovider multilevel networks.