I did some extremely rough numerical experiments with the TCP throughput algorithm. Results for TCP throughput in bits/sec at MSS=1440 bytes at various loss rates: 0.001% loss: Throughput 4.5 Mbits/sec (HD can survive) 0.01% loss: Throughput 1.4 Mbits/sec 0.1% loss: Throughput 458 Kbits/sec (VGA can survive) 1% loss: Throughput 144 Kbits/sec (good audio can survive) 10% loss: Throughput 43 Kbits/sec (crappy audio can survive) These are stable in the first 2 digits over a large range of RTT (1 ms to 100 ms). Interesting numerical result: In all cases, the second term of the TCP throughput denominator is less than 1% of the first term, so a reasonable approximation is: T = s / sqrt(p * 2/3) That's a simple formula. Harald