We present a novel low latency, high throughput and scalable optical packet switch (UPS) capable to optically interconnect hundreds of input/output ports. We focus on a strictly non-blocking Spanke architecture with contention resolution based on wavelength conversion. Highly distributed control of the UPS reduces the switching time to few nanoseconds regardless the amount of inputs/outputs. Queuing node analysis (mean values analysis) of input buffers in a computer communication network with windowflow control confirms that the new architecture, unlike rearrangeable nonblocking (i.e. Benes) architecture, can operate with low latency and high throughput with a very large amount of input/output ports
