Optical packet switching for high-performance computing.

摘要

The success of next generation high-performance computing systems will critically rely on large scale packet switching fabrics that can provide ultrahigh bandwidths with very low switching latency. Current computing systems that use electronic switching and interconnection become constrained by the inherent limitations of electronics aggravated by increasing pin-out density and concomitant severe electromagnetic interference (EMI). A natural solution for this so called electronic bottleneck is to replace the electronics with optical technologies that are capable of transmitting very high bandwidths data over long distances EMI free, while providing transparency to the data coding. However, optics cannot simply replace electronic switching fabrics as it lacks the capability to process and buffer data in the necessary capacities and densities required for large switches. Therefore, a large-scale switching fabric that utilizes optical technologies must be accomplished with a new architecture that can exploit the advantages of optics and electronics in synergy.; This dissertation presents theoretical and experimental research results on a novel optical packet switching architecture for high-end computing applications. The switch architecture, termed Data Vortex, is studied by numerical simulations and experimentally in a testbed configuration. The unique topology design and an embedded control scheme of the Data Vortex eliminate the need for optical buffering and requires minimal logic function within the routing nodes. These two attributes greatly facilitate an optical implementation of a switch fabric based on the Data Vortex architecture. WDM-encoding techniques are employed to further enhance the throughput and latency performance. Numerical simulation results have shown high scalability of the Data Vortex architecture with sustained large throughput, low switching latency, and small latency variations.; Moreover, the architecture shows its robust performance with respect to non-ideal traffic conditions such as non uniform and bursty packet distributions. We also present an experimental implementation of the Data Vortex in several prototype testbed configurations. The enabling optical and electronic technologies for the routing node subsystem implementation are evaluated. The results successfully demonstrate the basic packet routing functions, and a multiple-hop routing of six cascaded nodes is shown in a re-circulating testbed. The results also demonstrate the proper traffic control scheduling within the Data Vortex switch.