[TriLUG] speedtests

[Steven Tardy via TriLUG]

> I have spectrum cable service for my internet. Decided to test the
> speed using dslreport's speedtest. I selected cable and in no time,
> received an answer which wasn't too speedy.
>
> Decided to use fiber and tested again. The result was much better.
>
> How can this be?


There is a LOT of math behind “how fast is network connection” beyond
negotiated wire/link rate.
  https://en.m.wikipedia.org/wiki/TCP_tuning

The sender can only send the TCP window size before waiting for an ACK, so
throughput of a single TCP stream is a bit latency dependent.
Did the “other” side have different ping/latency times?

Was ther packet loss during the test?

How many parallel streams were sent?

Maybe the “fiber” option provided different TCP settings.

Did you redo the original test? Was it slow again?

Packet captures of (the first few 10s of MBs) may help uncover any
differences.