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In this paper, we propose a new restoration algorithm for disaster recovery in Elastic Optical Networks (EONs). The algorithm considers the different requirements on restoration delay and bandwidth degradation while restoring over multiple routes. Furthermore, the algorithm is able to adapt the connection recover process to the post-disaster network conditions and, consequently, increase the number of restored connections. Results indicate that the proposed strategy is able to improve connections restorability and decrease bandwidth blocking probability when compared to restoration approach based on bandwidth degradation and multipath recovery.

All-optical (transparent) wavelength-division multiplexing (WDM), a cost-effective and low power consumption solution for core transport networks, suffers from physical-layer impairments that accumulate along optical paths. In this context, it is important to find dynamic routing schemes with good performance that can consider the optical-layer constraints. In this paper, we propose the alternative least loaded under physical impairments (ALLPI) and the ALLPI with threshold (ALLPI-TH) algorithms. These are heuristic routing methods by which the lightpath requests that cannot be provisioned based on the shortest physical distance are established over least-loaded routes, provided that the selected lightpaths satisfy the impairment constraints (OSNR and PMD). Either dispersion-limited or noise-limited network scenarios were studied, for the bit rate of 40 Gbps. The results indicate that the ALLPI-type algorithms produce significantly lower blocking probabilities when compared to the reference algorithms, especially for a highly-connected network and at higher loads.