Abstract: A capture buffer stores data frames captured from a network which includes a data storage region for storing content data of the or each data frame received from the network, and for storing a descriptor associated with the or each data frame received from the network. The invention further includes an auxiliary storage region for storing an indicator of a property of a frame.

Abstract: A data merge unit is provided for providing an interleaved data stream, the data stream including data frames received on two or more input channels, wherein data frames from each of the two or more input channels are arranged in time-slots of the interleaved data stream. The data merge unit comprises an input unit to receive data frames from two or more input channels, a frame merge buffer arranged to receive data frames from the two or more input channels via the input unit and store said data frames; and, an output generator to generate the interleaved data stream, the output generator being configured to select complete data frames from the frame merge buffer and arrange said complete data frames in the interleaved data stream.

Abstract: A traffic generator for generating a packet information stream that includes plural information cells has plural memory regions. Each memory region contains identical data in the form of plural information cells. A memory-reading device reads information cells from the plural memory regions in an alternating manner such that, as an information cell is being read from one of the memory regions, the next memory region from which the next information cell is to be read can be activated. In this way, the next information cell can be read from the next memory region substantially as soon as the previous information cell has been read from the first memory region, thereby to generate a packet information stream from the read information cells.