On 29 Mar 2012, at 13:04, Harald Alvestrand wrote:
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.
Add the RTT, and you get the usual TCP throughput approximation. That seemed to be the suggestion to use from ICCRG. -- Colin Perkins http://csperkins.org/