Protection and Restoration Strategies in WDM Mesh Networks

This paper analyzes strategies for protection and restoration in a WDM network supporting two main classes of services. We refer to a scenario in which the optical network interacts with Multi-Protocol Label Switching (MPLS) based networks. We analyze routing, wavelength assignment, and protection/restoration issue. First the analysis is done at a pure optical level, handling the traffic with wavelength granularity. Then the option of a routing coordinated between the MPLS and optical layers is taken into account. In this case, there is the possibility to route the traffic on a LSP basis, providing a more efficient use of optical resources and restoration capabilities at the expense of an increase of electrical processing.