Scalable Communication for High Performance and Inexpensive Reliable QoS using Relaxed Recovery

Providing high quality-of-service using a single reserved path easily suffers from single link failures. This paper provides a scalable solution, TPmax-R, to tolerate single link failures. TPmax-R is based on an existing method, AvoidPBO-R. TPmax-R reduces the communication cost incurred by AvoidPBO-R to a scalable level. Instead of broadcasting routing information of all the flows in the network, TPmax-R source nodes communicate only link-based information to each other. TPmax-R pairs a reserved primary path with a well chosen unreserved backup path. Conflicts that might occur in the event of failure are predicted and backup paths are chosen to avoid these conflicts. By carefully planning the backup paths, the resulting service quality provided to the flows after re-routing is expected to be very close to that before the failure. Initial simulations show that TPmax-R provides competitive service quality after the failure while using less overhead.