The Advantages of Backup Reprovisioning After Failure Repair (and Failure Arrival) in Telecom Mesh Networks

Survivability is a key concern in modern telecom mesh networks because of the enormous capacity of a telecom link which is usually an optical fiber employing wavelength-division multiplexing (WDM). Backup bandwidth reprovisioning has been shown to be an effective approach for improving network survivability as well as preventing existing services from unnecessary interruption. We investigate the advantages of reprovisioning new backup paths for connections when a previous failure is repaired (as well as when a network failure occurs). We consider reprovisioning of backup paths either (1) for unprotected or vulnerable connections that lose their primary or backup paths due to a previous failure and fail to be reprovisioned when the failure happens due to resource limits, or (2) for all existing connections in the network. The pros and cons of the two policies are investigated. A wavelength-convertible network and shared-path protection are assumed in this study. We compare the performance of our dynamic reprovisioning approach with a conventional scheme which reprovisions backup paths for connections only when a network failure occurs. The simulation results demonstrate that our approach achieves more network robustness and better backup capacity optimization.