Q:

Does GCM requires Internet Connection? 

Im using GCM to get Notifications for my Android App. 
When registering at GCM you have to call:
@Override
protected String doInBackground(Void... params) {
    String registrationID = "";
    GoogleCloudMessaging gcmObject = null;

    try {
        gcmObject = GoogleCloudMessaging.getInstance(this.context);
        registrationID = gcmObject.register(Globals. GOOGLE_PROJECT_ID);
    } catch(IOException e) {
        registrationID = null;
    }

    return registrationID;
}

Is it neccessary to have connection to the internet for that call? 
Im asking because i have problems in my intranet where i test my 
application. 

A:

Yes you do need internet because there is a call to register your device so you can get your GCM token

