SIMULATED · OUTPUT 1 HELD BUSY
STEP 1
One queue per input
Packets wait in arrival order. Output 1 is busy, so the packet at the head waits, and every packet behind it waits too, even those bound for free outputs. This is head-of-line blocking.
STEP 2
One queue per output
Virtual Output Queueing gives each input a separate queue for every destination. Packets for output 1 still wait, but they no longer hold up the rest, and the delivered count climbs.
STEP 3
Inn + voq
Innovation, and the systems engineering under it. Said aloud, the name is invoke: to call something into being.