A four-terabit packet switch supporting long round-trip times

A four-terabit packet switch supporting long round-trip times is described. The switch uses a combined input- and crosspoint-queued structure with virtual output queuing at the ingress. The system is build from four different CMOS ASIC building blocks, using a total of 40 chips for the switching core and 64 fabric interface chips on the line cards. Benefits include high scalability, thoroughput and quality of service.