Limitations and Perspectives of Optically Switched Interconnects for Large-scale Data Processing and Storage Systems

ABSTRACTThe ever-growing Internet data traffic leads to a continuously increasing demand in both capacity and performance of large-scale Information and Communication (ICT) systems such as high-capacity routers and switches, large data centers, and supercomputers. Complex and spatially distributed multirack systems comprising a large number of data processing and storage modules with high-speed interfaces have already become reality. A consequence of this trend is that internal interconnection systems also become large and complex. Interconnection distances, total required number of cables, and power consumption increase rapidly with the increase in capacity, which can cause limitations in scalability of the whole system. This paper addresses requirements and limitations of intrasystem interconnects for application in large-scale data processing and storage systems. Various point-to-point and optically switched interconnection options are reviewed with regard to their potential to achieve large scalability while reducing power consumption.