A system for adjusting the window size of a TCP packet on a packet network including a sending network element in communication with a receiving network element for transmitting and receiving data packets between the sending network element and the receiving network element on the packet network, wherein at least one of the sending network element and the receiving network element is configured to determine network performance information of the packet network; and adjust the window size of the TCP packet based on the network performance information. A method for adjusting the window size of a TCP packet on a packet network is also included.