I've made a web interface for using iperf to test link speeds on the mesh. Just trying this out to see how well it works. You need to install it on at least 2 nodes on your mesh. Then use the ui at http://<node>:8080/iperfspeed to run a speed test. It will login to the server node and start iperf as the server, then login to the client and run iperf against the server for 10 seconds and record the result. See screen shot below.
To install you need to have iperf on both nodes. If your node is connected to the Internet just use the drop down box on the setup page. Otherwise here are links to the packages you need to install before installing iperfspeed on your node:
Then install iperfspeed:
Let me know if it works for you.
Oh one note. After you install iperf on your node you will need to reboot for the firewalls rules to take effect and allow access to iperf.