A data processing system comprising a plurality of interconnected nodes, each node comprising a media processor and one or more ports, each port connected to a respective media processor. Each port is configured to be active or passive, an active port being arranged, upon receipt of data, to transfer the received data to its output, a passive input port being arranged, upon receipt of data, to retain the received data and to transmit the received data to its output when the received data reaches a specific size, and a passive output port being arranged to trigger the receipt of data when the data capacity of the output port reaches a specific size.