Protection approaches for dynamic traffic in IP/MPLS-over-WDM networks

Due to the explosive growth of data-related traffic driven by the Internet, network reliability becomes an important issue. We investigate various protection approaches to handle failures for dynamic traffic demands in IP/MPLS-over-WDM networks. An LSP can be protected at either the IP/MPLS layer or the optical layer. In IP/MPLS layer protection, an LSP is protected by providing a link-disjoint backup LSP between its end nodes. In optical layer protection, an LSP is protected by the backup lightpath of each lightpath traversed by the LSP. We present two integrated routing algorithms: hop-based integrated routing algorithm and bandwidth-based integrated routing algorithm (BIRA) to set up the restorable bandwidth-guaranteed paths efficiently. Then we present a multilayer protection scheme for multiclass traffic in such networks. This scheme takes into account the different QoS and recovery requirements of the traffic to provide protection capability either at the MPLS layer or at the optical layer in a cost-effective manner. We use the connection blocking probability and number of optical-electrical-optical conversions as performance metrics to compare various protection approaches.