An new approach to multi‐layer network survivability: strategies, model and algorithm

This paper studies multi‐layer survivability strategies in multi‐layer transport networks. Two escalation strategies, failure‐oriented and traffic‐oriented, are proposed, with the former reducing the time in both failure detection and notification, and the latter allowing priority restoration for different traffic. To reach the optimal spare resources for multi‐layer survivability, a new resource sharing pool (RSP) is provided, which allows resources to be shared among adjacent layers without incurring any additional resource on lower layers to provide for any redundant protection. The RSP is formulated as a difficult optimization problem, and can be combined with any escalation strategies and thus can be used in any type of multiple layer networks, such as WDM‐based SDH networks or IP over WDM networks. Finally, simulation is supplied to examine the efficiency of the RSP assuming the SDH‐based ATM transport network is in use.