What are we talking about? Android tries to send the packages over ‘http://clients3.google.com’ and if the answer is successfully you get an HTTP Response-Code 204 (the answer is correct but it doesn't contain any data). Basically the IP and a timestamp will be transmitted. Some of the domains used by Google to check for internet connection for Android. http://clients1.google.com/ http://clients3.google.com http://connectivitycheck.gstatic.com http://connectivitycheck.android.com and other domains used for this purpose by Google.