Having one application failed in Microsoft Certification, here are the testing notes recieved from Microsoft for testing applications that use Network Connection.
The application must run on any Windows Phone 7 device, regardless of model, screen size, keyboard hardware, and manufacturer.
NOTE: An application must be tested with a SIM in the device with data connection enabled by default. For an application that has network service dependency, the steps must be repeated without any data connection after disabling cellular data, wireless, and desktop tethered connections.
1. Install the application on two or more Windows Phone 7 devices and the application must install and uninstall without error.
2. Launch the application and comprehensively test the application's functionality and features to ensure there are no device specific issues.
3. Ensure that the application does not cause the device to hang or crash.
4. ***This step only applies to applications that require network service***
Disable the cellular connection by turning on "Airplane mode", turn off WiFi and ensure the device is not tethered to the desktop. Launch the application and ensure it launches or produces an error message stating it is unable to connect.