Para hacer tests de velocidad. Usa el puerto 5001

En el servidor:

iperf -s
root@ssh-1-esc-p:~# iperf -s  
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 85.3 KByte (default)
------------------------------------------------------------
[  4] local 192.168.1.101 port 5001 connected with 212.0.117.66 port 34685
[ ID] Interval       Transfer     Bandwidth
[  4]  0.0-10.1 sec  39.8 MBytes  32.9 Mbits/sec
[  5] local 192.168.1.101 port 5001 connected with 212.0.117.66 port 64073
[  5]  0.0-10.2 sec  39.0 MBytes  32.1 Mbits/sec
[  4] local 192.168.1.101 port 5001 connected with 212.0.117.66 port 4747
[  4]  0.0-10.1 sec  41.0 MBytes  33.9 Mbits/sec

En el cliente: jose@avtp67:~$ iperf -c lobo99.com

------------------------------------------------------------
Client connecting to lobo99.com, TCP port 5001
TCP window size: 85.0 KByte (default)
------------------------------------------------------------
[  3] local 10.9.1.50 port 42409 connected with 37.14.80.193 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec  41.8 MBytes  35.0 Mbits/sec