The details given on the NDT site were: Your system: Windows Vista version 6.0 Java version: 1.7.0_17 (x86) TCP receive window: 223200 current, 262080 maximum 7.9743E-5 packets lost during test Round trip time: 19 msec (minimum), 60 msec (maximum), 43.07 msec (average) Jitter: 41 msec 0 seconds spend waiting following a timeout TCP time-out counter: 228 202 selective acknowledgement packets received No duplex mismatch condition was detected. The test did not detect a cable fault. No network congestion was detected. No network address translation appliance was detected. 0.1153% of the time was not spent in a receiver limited or sender limited state. 88.09% of the time the connection is limited by the client machine's receive buffer. Optimal receive buffer: 268369920 bytes 0 duplicate ACKs set No congestion or cable faults found, so is there some other factor which would need investigation?