The invention includes an apparatus and method for switching packets
through a switching fabric. The apparatus includes a plurality of input
ports and output ports for receiving arriving packets and transmitting
departing packets, a switching fabric for switching packets from the
input ports to the output ports, and a plurality of schedulers
controlling switching of packets through the switching fabric. The
switching fabric includes a plurality of virtual output queues associated
with a respective plurality of input-output port pairs. One of the
schedulers is active during each of a plurality of timeslots. The one of
the schedulers active during a current timeslot provides a packet
schedule to the switching fabric for switching packets through the
switching fabric during the current timeslot. The packet schedule is
computed by the one of the schedulers active during the current timeslot
using packet departure information for packets departing during previous
timeslots during which the one of the schedulers was active and packet
arrival information for packets arriving during previous timeslots during
which the one of the schedulers was active.