Improving dependability of real-time communication with preplanned backup routes and spare resource pool

Timely recovery from network component failures is essential to the applications that require guaranteed-performance communication services. To achieve dependable communication, there have been several proposals that can be classified into two categories: reactive and proactive. The reactive approach tries to reroute traffic upon detection of a network link/node failure. This approach may suffer from contention and resource shortage when multiple connections need to be rerouted at the same time. The proactive approach, on the other hand, prepares a backup channel in advance that will be activated upon failure of the corresponding primary channel due to a broken link or node. The proactive approach, although it offers higher dependability, incurs higher routing overhead than the reactive approach. We propose a hybrid approach that reduces signaling overhead by decoupling backup routing from resource provisioning. We also propose an efficient backup routing algorithm for the hybrid approach. Our in-depth simulation results show that the proposed approach can achieve the ability of failure recovery comparable to the proactive scheme without the need for broadcasting the routing information.