Issue No.01 - January/February (1999 vol.19)
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/40.748793
Crossbar switches are frequently used as the internal switching fabric of high-performance network switches and routers. However, an intelligent centralized scheduler is needed to configure the crossbar fairly and with high utilization. In this paper, we describe the design and implementation of a scheduling algorithm for configuring crossbars in input-queued switches that support virtual output queues and multiple precedence (priority) levels of unicast and multicast traffic). This design was carried out for the Tiny Tera prototype at Stanford University, a fast label-swapping packet switch supporting 32 ports, each operating at 10 Gb/s (OC192 line rate). The scheduler is designed to configure a crossbar once every 51ns. The scheduler implements the ESLIP scheduling algorithm which consists of multiple round-robin arbiters.
Pankaj Gupta, Nick McKeown, "Designing and Implementing a Fast Crossbar Scheduler", IEEE Micro, vol.19, no. 1, pp. 20-28, January/February 1999, doi:10.1109/40.748793