Three-stage switch fabric with buffered crossbar devices

A switch fabric for routing data from one or more sources towards one or more destinations, comprising a switching stage configured between an input stage and an output stage wherein:

• the input stage is configured to receive the data transmitted from the one or more sources and forward the data to the switching stage;
• the switching stage is configured to route the data received from the input stage to the output stage;
• the output stage is configured to transmit the data received from the switching stage towards the one or more destinations;
• the input stage comprises a plurality of input devices, each input device performing a port expansion function;
• the switching stage comprises one or more crossbar devices, each crossbar device performing a data routing function;
• the output stage comprises a plurality of output devices, each output device performing a port contraction function;
• each input device transmits bids to the one or more crossbar devices to request connections through the switching stage for routing the data to the output devices;
• and
• each crossbar device comprises:
• (1) a bid arbitrator configured to determine whether to accept or reject each received bid, wherein, in response to a collision between multiple bids, the bid arbitrator accepts two or more of the colliding bids in a single time slot;
• and
• (2) memory for storing one or more accepted cells for the same output device, wherein the crossbar device can transmit grant signals for two or more accepted bids for the same output device in a single time slot.