Time-Division based Scheduling Scheme for Hybrid Optical/Electrical Data Center Network

Past few years have witnessed the great development of Optical Circuit Switches (OCSes), which support high and dynamic bandwidth at low per-bit overhead in the data center network. Although OCSes deliver variety of attractive properties, the challenge still remains due to the unneglectable reconfiguration delay of OCSes. Previous OCS-based proposals amortize the long reconfiguration overhead by reconfiguring OCSes at intervals of a few 100s of milliseconds, which inevitably incurs a mass of packets waiting during reconfiguration intervals, hence the degradation of network performance happens. In this paper, we propose an OCS-based scheduling scheme named Time-Division Scheduling (TDS), which groups OCSes and reconfigures different groups in sequential time slots, instead of periodically reconfiguring all OCSes. TDS diminishes the impact of the long reconfiguration delay with mere directly software modifications. We evaluate the performance of TDS via OMNET++. The experimental results show that TDS delivers significant performance enhancements in latency and benefits slightly on the throughput.