The robots in the virtuallab are controlled using TCP/IP connection on port 7123, or 3331-3334 for the second and third robot. You can find out which robot you are controlling by looking closer at the link(s) where the robot icon(s) point(s). Look at the "lab=" variable in the URL.
lab=1 | use port 7123 |
lab=2 | use port 3331 |
lab=3 | use port 3332 |
lab=4 (simulated) | use port 3333 |
lab=5 (simulated) | use port 3334 |
In order to connect to the robots, your firewall should allow outgoing TCP traffic on these ports, and traffic on established connections in both ways.
If your firewall will block the communication, you will not be able to connect to the robots, most likely getting the timeout error.