Abstract: A packet router has an input stage (1), an output stage (15) and a coupling stage (10) for coupling the input and output stages. The input stage has plural input devices, the output stage has plural output devices and the coupling stage provides paths for signals between output elements of the input devices and input elements of the output devices. Each input device has circuitry arranged to respond to packet destination data of a packet received by its input device for adding, to the packet data of the packet, information indicative of a router output node at which the packet is to be output. The router has a controller (20) connected to the input stage and to the coupling stage for causing packets to be output to said coupling stage in dependence on this information. Each output device has circuitry for removing the information prior to output of packets.