A system for adjusting the window size of a TCP packet on a packet network including a receiving transport layer device configured to determine network performance information of the packet network; concatenate the network performance information into the data packets; adjust the window size of the TCP packet based on the network performance information; a non-transport layer device in communication with the receiving transport layer device for receiving the data packets; and a transport layer device in communication with the non-transport layer device, wherein the non-transport layer device forwards the data packets on to the transport layer device. A method for adjusting the window size of a TCP packet on a packet network is also included.