A communication system comprising: a first network node and a second network node, wherein the first network node is arranged to transmit a flow of data records to the second network node via a network, and the second network node comprises a data record processing module arranged to receive and process the data records; a controller for controlling the transmission of data records by the first network node to the second network node, the controller comprising: an acquisition module operable to acquire data records of the flow of data records; a pattern recognition module arranged to determine whether the data records acquired by the acquisition module match a part of a pattern of one or more patterns each defining a respective sequence of data records and, when the acquired data records match part of a pattern of the one or more patterns, to identify which of the one or more patterns the acquired data records match; and a control signal generator module arranged to generate, when the pattern recognition module has identified a pattern matching the acquired data records, an indication of the matching pattern and at least one transmission control signal for the first network node to prevent the first network node from transmitting to the second network node remaining data records in the flow that follow the acquired data records and whose number is equal to the number of data records in the remaining part of the matching pattern, the remaining part of the matching pattern being the part of the sequence of data records of the pattern other than the part found to match the acquired data records; and a pattern handler comprising a data store that stores the one or more patterns, the pattern handler being communicatively coupled to the data record processing module via a communication path that is separate from the network and responsive to the indication of the matching pattern to predict the remaining data records using the pattern of the stored patterns that is indicated by the indication, and provide the predicted data records to the data record processing module via the communication path. a first network node and a second network node, wherein the first network node is arranged to transmit a flow of data records to the second network node via a network, and the second network node comprises a data record processing module arranged to receive and process the data records; a controller for controlling the transmission of data records by the first network node to the second network node, the controller comprising: an acquisition module operable to acquire data records of the flow of data records; a pattern recognition module arranged to determine whether the data records acquired by the acquisition module match a part of a pattern of one or more patterns each defining a respective sequence of data records and, when the acquired data records match part of a pattern of the one or more patterns, to identify which of the one or more patterns the acquired data records match; and a control signal generator module arranged to generate, when the pattern recognition module has identified a pattern matching the acquired data records, an indication of the matching pattern and at least one transmission control signal for the first network node to prevent the first network node from transmitting to the second network node remaining data records in the flow that follow the acquired data records and whose number is equal to the number of data records in the remaining part of the matching pattern, the remaining part of the matching pattern being the part of the sequence of data records of the pattern other than the part found to match the acquired data records; and an acquisition module operable to acquire data records of the flow of data records; a pattern recognition module arranged to determine whether the data records acquired by the acquisition module match a part of a pattern of one or more patterns each defining a respective sequence of data records and, when the acquired data records match part of a pattern of the one or more patterns, to identify which of the one or more patterns the acquired data records match; and a control signal generator module arranged to generate, when the pattern recognition module has identified a pattern matching the acquired data records, an indication of the matching pattern and at least one transmission control signal for the first network node to prevent the first network node from transmitting to the second network node remaining data records in the flow that follow the acquired data records and whose number is equal to the number of data records in the remaining part of the matching pattern, the remaining part of the matching pattern being the part of the sequence of data records of the pattern other than the part found to match the acquired data records; and a pattern handler comprising a data store that stores the one or more patterns, the pattern handler being communicatively coupled to the data record processing module via a communication path that is separate from the network and responsive to the indication of the matching pattern to predict the remaining data records using the pattern of the stored patterns that is indicated by the indication, and provide the predicted data records to the data record processing module via the communication path.