Optical Flow Switching with Time Deadlines for High-Performance Applications

This paper focuses on the design and analysis of scheduling approaches for Optical Flow Switching (OFS) serving high performance applications with very stringent time deadline constraints. In particular, we attempt to meet setup times only slightly longer than one roundtrip time with networks at moderate to high loading. This paper proposes three possible scheduling mechanisms for OFS connection setup in a WDM network: (i) a simple algorithm, which awards pre-emptive priority to applications requiring time deadline performance; (ii) a multi-path probing mechanism using only coarse average loading information (i.e., no detailed network state information) but without pre-emption; and (iii) a multi-path probing mechanism using periodically updated network state information and without pre-emption. The updating scheme calls for a slow control plane, which refreshes and broadcast network states only periodically on the order of seconds or longer. Our results show that for a low blocking probability, the update interval must be a fraction of the mean service time of transactions. We conclude that this algorithm, a combination of both slow centralized and fast distributed processes, delivers an efficient and scalable control design for a high-speed transport network of the future.