measuring Network Speed with BBB

There is a Make Project that runs on BBB, that measures the speed of the network at the moment.

Lined below:

As per my understanding, IP packets are delivered directly through a router sockets to the respective computer connected to the correct socket. In that case, BBB would be unable to measure/receive the packets (normally) through its Ethernet socket.

I am wondering how the above project is made possible.

Thank you very much!

Look into two programs you can install using apt-get. They are “iftop” and “vnstat”. They work quite well to see what is going on.