Cannot view over the Internet. #42

It works over my WiFi connection.

When I turn off WiFi on the phone, the app gives me an external IP address, 
e.g. 10.66.188.110:8080. I cannot ping this address. Is this a limitation of IP 
technology over a mobile data connection? That you are not able to connect to a 
mobile based server? Or should it be possible but there is a reason why it does 
not work with this app?