Hi! I am writing to explain how to test your network connection between your client (Windows or Linux) and another client (say, a remote server). The tool is iperf version 3.

You can find some useful explanations and examples on this French site: https://iperf.fr/ But the version stays at 2 which does not have some amazing new features.

With iperf3 you will not need to set parameters on the server side because the client will negotiate the parameters with the server.

Here are some useful examples you may want to test with iperf3:

# Classic mode (10 seconds)
iperf3 -c 10.10.10.1 -w 300k

# 2 Connections
iperf3 -c 10.10.10.1 -w 300k -P 2 

# Transfer 10MB instead of 10 sec
iperf3 -c 10.10.10.1 -w 300k -n10M

iperf3 for Windows

You may want to use the compiled binary on windows systems:
http://pan.baidu.com/s/1kTFw5PP

iperf3 for Linux

I don’t want to explain to much on how to install it for your Linux distribution. I believe you can find the right package. LOL

# Install iperf3 on CentOS 7
rpm -ivh http://mirror.as24220.net/pub/epel//7/x86_64/i/iperf3-3.0.10-1.el7.x86_64.rpm

# Install iperf3 on CentOS 6
rpm -ivh http://dl.fedoraproject.org/pub/epel/6/x86_64/iperf3-3.0.10-1.el6.x86_64.rpm

# Add firewall rules on both nodes
iptables -A INPUT -i ppp+ -p tcp --dport 5201 -j ACCEPT