A data processing system comprising: a processing subsystem supporting a plurality of consumers, each consumer being arranged to process messages received into a corresponding receive queue; a network interface device supporting a virtual interface for each of the receive queues; and a hardware accelerator coupled to the processing subsystem by the network interface device and configured to parse one or more streams of data packets received from a network so as to, for each consumer: identify in the data packets messages having one or more of a set of characteristics associated with the consumer; and frame the identified messages in a new stream of data packets addressed to a network endpoint associated with the virtual interface of the consumer so as to cause said new stream of data packets to be delivered into the receive queue of the consumer.