iperf different numbers on server vs. client
I'm using iperf and get vastly different bandwidth results from the server
and client's perspective when using parallel connections from the client
and specifying the -n and -l options to control how much data is sent from
the client.
The results are very similar, if not identical, when using the defaults.
Why are the results so different? I would expect that both would report
the same values. If not, what is the server reporting its numbers on?
Which one would be a more reliable measure?
The OS is Solaris 5.8; iperf version 1.6.5 (13 Jan 2003) pthreads
Thanks,
-Jason
Server (removing extraneous information lines):
iperf -s -p 5001
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 64.0 KByte (default)
------------------------------------------------------------
[ ID] Interval Transfer Bandwidth
[ 6] 0.0- 0.0 sec 4.00 KBytes 59.3 Mbits/sec
[ 7] 0.0- 0.0 sec 4.00 KBytes 437 Mbits/sec
[ 8] 0.0- 0.0 sec 4.00 KBytes 504 Mbits/sec
[ 9] 0.0- 0.0 sec 4.00 KBytes 141 Mbits/sec
[ 10] 0.0- 0.0 sec 4.00 KBytes 529 Mbits/sec
[ 11] 0.0- 0.0 sec 4.00 KBytes 475 Mbits/sec
[ 12] 0.0- 0.0 sec 4.00 KBytes 520 Mbits/sec
[ 13] 0.0- 0.0 sec 4.00 KBytes 282 Mbits/sec
[ 5] 0.0- 0.0 sec 4.00 KBytes 4.81 Mbits/sec
[ 4] 0.0- 0.0 sec 4.00 KBytes 1.45 Mbits/sec
Client:
iperf -c dh12017 -p 5001 -n 4k -l 4k -P 10
------------------------------------------------------------
Client connecting to dh12017, TCP port 5001
TCP window size: 64.0 KByte (default)
------------------------------------------------------------
[ ID] Interval Transfer Bandwidth
[ 6] 0.0- 0.0 sec 4.00 KBytes 24.5 Mbits/sec
[ 7] 0.0- 0.0 sec 4.00 KBytes 10.9 Mbits/sec
[ 8] 0.0- 0.0 sec 4.00 KBytes 5.98 Mbits/sec
[ 10] 0.0- 0.0 sec 4.00 KBytes 4.20 Mbits/sec
[ 11] 0.0- 0.0 sec 4.00 KBytes 3.78 Mbits/sec
[ 12] 0.0- 0.0 sec 4.00 KBytes 3.47 Mbits/sec
[ 13] 0.0- 0.0 sec 4.00 KBytes 3.16 Mbits/sec
[ 5] 0.0- 0.0 sec 4.00 KBytes 6.03 Mbits/sec
[ 4] 0.0- 0.0 sec 4.00 KBytes 6.89 Mbits/sec
[ 9] 0.0- 0.0 sec 4.00 KBytes 3.45 Mbits/sec