Concurrent Failures and Redundant Protection Problem in Hierarchical GMPLS Networks

The generalized multiprotocol label switching (GMPLS) networks attain a hierarchical structure, and each layer maintains an independent protection mechanism, resulting in redundant protection. The common pool method provides a basic approach to solve the redundant protection problem. Although the common pool method is simple and robust, however it can fail in some cases. This work first shows that none of the prior work satisfies both redundant protection and two links failure problem simultaneously. Moreover, this work also presents a new type of two links failure problem (i.e., the failure of two links at two different layers), which can happen frequently and the common pool method cannot cope with. To solve the proposed two links failure problem, while minimizing the cost of redundant protection problem, this work proposes a new protection scheme for hierarchical GMPLS networks.