Guaranteeing packet order in Load Balanced distributed Schedulers for WASPENT optical packet switches

In [5] we proposed the load balanced WASPNET scheduler (LBWS), a novel scheduling approach for WASPNET optical packet switching (OPS) nodes. Unlike the original WASPNET description, LBWS is fully distributed and its computational cost is independent of switch size. Since it predicts packet delays at packet ingress based on a deterministic evolution of the switch configuration, it is not necessary to emulate RAM memories. However, LBWS does not maintain packet sequence. In this paper we present the LBWS algorithm with packet ordering (OLBWS), the first proposal to prevent mis-sequencing in a LBWS scheduler. We show that, despite the simplicity of the algorithm, a reasonable throughput can be achieved.