Patent ID: 7035214

Claim:
A method of transmitting data in a data communications network, comprising the steps of: (i) establishing a connection-oriented communications link between a transmitter and a receiver through a Transmission Control Protocol (TCP) handshake, the communications link having a congestion window set to an initial length; (ii) transmitting data packets in TCP from the transmitter to the receiver; (iii) sending periodically a keep-alive request from the transmitter to the receiver, whereupon a re-transmission time-out timer is set, (iv) determining, at the transmitter, if an acknowledgment to the keep-alive request is not received before expiry of the re-transmission time-out timer, whereupon the transmitter backs off for a predetermined period; (v) detecting a missing data packet at the receiver; (vi) sending a negative acknowledgment from the receiver to the transmitter for the missing data packet, the receiver being unresponsive to any packets from the transmitter unless the receiver detects the missing data packet; (vii) decreasing, at the transmitter, the length of the congestion window in response to receipt of the negative acknowledgment; and (viii) re-transmitting the missing data packet.