Hybrid deflection and retransmission routing schemes for OBS networks

Deflection routing is an attractive scheme for resolving the burst contention problem in optical burst switching (OBS) networks and retransmission of rejected packets is widely accepted as a basic mechanism for guaranteeing the robust operation of IP networks. In this paper, we explore the potential benefits of combining the deflection routing and burst retransmission schemes in OBS networks. We first demonstrate that if these two schemes are not combined appropriately, the network performance may be significantly degraded. We then suggest a novel approach to combining deflection routing and burst retransmission, such that the resulting hybrid algorithm can always guarantee a better overall performance in terms of burst loss and end-to-end delay than that of both the conventional pure deflection routing and the pure retransmission scheme, as verified by the simulation results based on the ns-2 simulator and two typical network topologies.