Design models for robust multilayer next generation Internet core networks, carrying elastic traffic

This paper presents three mathematical formulations for designing robust two-layer networks carrying elastic traffic. The formulations differ by the way flow reconfiguration is performed in the case of link failures. An iterative algorithm to solve the problems is given and an extensive numerical study is provided comparing the effectiveness of the three reconfiguration approaches. The formulations can be applied for designing next generation Internet (NGI) core networks with two-layer IP-over-WDM structure.