Some questions about Iperf
I've been using Iperf for a few months now and I have a question about a
certain scenario I setup and tested using Iperf.
What I did was setup two fast computers (1GHz PIII w/512MB RAM 10/100 Eth)
in a peer-to-peer network with just themselves via use of a Cat5e crossover
cable. After making sure both systems ethernet cards (onbaord Intel 82557)
were set to 100Mbit Full-Duplex I setup to sets of Iperf
cilent/servers. That is, each computer would be sending a Iperf stream to
the other while simultaneously recieving an Iperf stream. When I ran these
tests the speeds reported on the clients on both ends was roughly 50Mbps. I
would have expected to see somewhere in the range of 90-92Mbps since this
was a full duplex 100Base-TX network scenario.
Is there something wrong with my understand of the the full-duplex nature
on Ethernet or is there something about how Iperf sets up its test streams
that would cause a simultaneous bi-directional test like I setup to be
invalid. I guess what I am asking is, is Iperf only accurate for
unidirectional tests?
Any help is greatly appriciated, thanks!
-Daniel E. Spisak