Predicting TCP throughput

Glen Kent glen.kent at gmail.com
Thu May 28 01:15:44 UTC 2015


Hi,

I am looking at deterministic ways (perhaps employing data science) to
predict TCP throughput that i can expect between two end points. I am using
the latency (RTT) and the packet loss as the parameters. Is there anything
else that i can use to predict the throughput?

A related question to this is;

If i see an RTT of 150ms and packet loss of 0.01% between points A and B
and the maximum throughput then between these as, say 250Mbps. Then can i
say that i will *always* get the same (or in a close ballpark) throughput
not matter what time of the day i run these tests.

My points A and B can be virtual machines spawned on two different data
centers, say Amazon Virgina and Amazon Tokyo? So we're talking about long
distances here.

What else besides the RTT and packet loss can affect my TCP throughput
between two end points. I am assuming that the effects of a virtual machine
overload would have direct bearing on the RTT and packet loss, and hence
should cancel out. What i mean by this is that even if a VM is busy, then
that might induce larger losses and increased RTT, and that would affect my
TCP throughput. But then i already know what TCP throughput i get when i
have a given RTT and loss, and hence should be able to predict it.

Is there something that i am missing here?

Thanks, Glen



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