Patent ID: 8300545

Claim:
A method comprising: monitoring, at a network device located at a demarcation point in a network, performance of a network application relative to a first network latency condition between a first transmission control protocol (TCP) host on a first side and the demarcation point and a second network latency condition between a second TCP host on a second side and the demarcation point; and wherein the first network latency condition is determined by recording the arrival time, at the demarcation point, of packets transmitted by the second TCP host to the first TCP host; recording the arrival time, at the demarcation point, of respective acknowledgement packets corresponding to the packets transmitted by the second TCP host; and computing the difference between the arrival times of the packets and corresponding acknowledgement packets; wherein the second network latency condition is determined by recording the arrival time, at the demarcation point, of packets transmitted by the first TCP host to the second TCP host; recording the arrival time, at the demarcation point, of respective acknowledgement packets corresponding to the packets transmitted by the first TCP host; computing the difference between the arrival times of the packets and corresponding acknowledgement packets; and wherein the first and second network latency conditions are expressed as congestion index values, the method further comprising: comparing congestion index values over time.