An On-Line Path Computation Algorithm for a Protected GMPLS Enabled Multi-Layer Network

In this paper we focus on 1+1 dedicated protection in multi-layer network formed by Connection-Oriented (CO) Ethernet over Wavelength Switched Optical Networks (WSON) under the framework of a GMPLS control plane. We propose a dynamic path computation algorithm that is used for computing both the working and protecting paths, ensuring the Shared Risk Link Group (SRLG) disjointness at both layers. The proposed algorithm favors the usage of Forwarding Adjacency (FA) TE links over a new LSC LSP establishment, where a multiple change of the layer is possible. It accommodates the requested traffic depending on the current state of both, optical and FA TE links. By doing so, it keeps the network resource utilization balanced at both involved layers. Through an extensive set of simulations using two network topologies, NSFNET and Pan-European, we compare the proposed algorithm with two algorithms found in the literature. It is shown that the algorithm improves the network performance regarding the connection blocking probability and survivability for a given failure model.