A method of reducing the bandwidth usage of a network comprises intercepting traffic between a TCP server and a TCP client using TCP protocols that use client acknowledgements; identifying client acknowledgements from the TCP protocols; identifying the sequence number of a last received client acknowledgements from the intercepted traffic; identifying the sequence number of a last sent client acknowledgement from the intercepted traffic; calculating an unacknowledged byte value based on the difference between the last received client acknowledgement sequence number and the last sent client acknowledgement sequence number; comparing the calculated unacknowledged byte value with a predetermined threshold value, to determine whether the calculated unacknowledged byte value is at least as great as the predetermined threshold value; and transmitting the identified client acknowledgements into the network when the compared unacknowledged byte value is at least as great as the predetermined threshold value.