Abstract: A network device that is inserted in the path of traffic in a packet network, and the associated procedures and controller algorithms for monitoring the performance of aggregates of short lived Transmission Control Protocol (TCP) Connections flowing over a bottleneck link and dynamically managing their performance. TCP operates by allowing a certain window of data to be outstanding between the source and the receiver of each transfer and if many transfers attempt to share the network, congestion occurs, thus reducing the transmission rate of ongoing transfers. The method and apparatus aim at the performance of an aggregate of short-lived connections and hence measure only the RTT (Round Trip Time) for the aggregate and determine a window for the aggregate. By setting a target performance for the entire aggregate a measurement is made over the aggregate to determine the current performance level for each value of control eg. A RD (Random Drop) probability, or a value of MWA (Modified window Advertisement).