General :: No Network Timeout When Connection Lost On Device But Works In Emulator

I'm developing an App that sends keep-alive packets to its server to ensure the connection is still alive.

The server is java based and thus easily to run. I run the server on a virtual machine (Windows 7). After my App is connected and the first keep-alive packet is received (it displays a message in its console output) I disable the network interface in Windows. This step is very important because by disabling it, there is no way to send any packet back to the client informing it about network changes.

The clients are configured to send every 25 seconds a keep-alive packet, so you don't need to wait long.

When you use the sample JavaClient on Windows 7 it takes less than a minute after the keep-Alive packet and an exception is thrown which triggers reconnection (which currently can't occur). This is the expected behaviour.

When you use the sample Android App on an emulator (tested Android version 2 and 4) it is the same behaviour. So in less than a minute after the keep-alive packet it recognises that the connection is dead, throws an exception, this triggers reconnection.

Problem is now when this App runs on a real device (tested several, Xpearia Arc S, one Cyanogen Mod 4 on Galaxy S3 and my Galaxy S3). I've waited 5 minutes, but there was no exception. This behaviour is reproducable.

Since this is a sample App, it uses no wakelock or service, so to test it is important to have it in foreground all the time (don't switch to other Apps or homescreen) and increase your display timeout to a few minutes to ensure that it doesn't go off. Use Logcat-Output to get informed whats happening, because there is no output in the App itself.

Now Sample-Code is in the attachement. Something had gone wrong. The Code consists of 3 Eclipse projects which you can easily import.