Adaptive fast retransmit threshold to make tcp robust to non-congestion events

Abstract

Mechanisms are disclosed for adjusting a fast re-transmit threshold (FRT) value for transmitting data streams over a computer system. One embodiment includes receiving, by a sender, a current fast re-transmit threshold value for a packet from a receiver. Further, these mechanisms include decreasing the size of the congestion window of the sender, and re-transmitting the packet to the receiver in network communication with the sender. Further still, the mechanisms include counting, by the sender, a number of dupacks after re-transmitting the packet until arrival, at the sender, of an acknowledgement (ACK) for the packet. Yet further, the mechanisms include determining, based on the size of the congestion window and the counting, a value of the FRT value. If the sender receives the ACK for the packet in less than one round trip time, then this may be a re-ordering problem for re-setting the FRT value.