Fair scheduling in an optical interconnection network

Existing fair scheduling schemes have focused primarily on scheduling multiple flows to a single output. The limited work that has focused on scheduling multiple flows to multiple outputs has assumed a non-blocking, slotted-time, cell-based network with a centralized controller. This paper presents a fair scheduler suitable for use in bufferless circuit-switched blocking networks operating with distributed, asynchronous controllers and variable length messages. We begin by describing the potential for starvation in the Gemini interconnect network, an optical, circuit-switched network. A proposed distributed fair scheduler is presented and shown to solve this problem. The tradeoffs and limitations of performing many-to-many fair scheduling in general, and that of our fair scheduler in particular, are discussed.