How to Check whether the connected network is having data communication or not continuously while the app is running?

My application completely depends on the network so I have to check whether the data communication is there between the application and my server and make a popup on communication lost and if not connected to Wifi or Mobile Data and if the connected service is having slow connection. I am using the following code where I can get whether the device is connected to the Wifi or mobile data and get the type of connection and also got the code to get the type of mobile network connected which is not working at all. please refer the following code...

 public void CheckInternet()
        {
            Plugin.Connectivity.CrossConnectivity.Current.ConnectivityChanged += delegate
            {
                if (!(Plugin.Connectivity.CrossConnectivity.Current.IsConnected))
                {
                    StartActivity(typeof(InternetCheckingView));
                }
                if (Plugin.Connectivity.CrossConnectivity.Current.IsConnected)
                {
                    ConnectivityManager connectivityManager = (ConnectivityManager)GetSystemService(ConnectivityService);
                    NetworkInfo networkInf = connectivityManager.ActiveNetworkInfo;
                    bool isOnline = networkInf.IsConnected;
                    NetworkInfo networkInfo = connectivityManager.ActiveNetworkInfo;
                    bool isWifi = networkInfo.Type == ConnectivityType.Wifi;
                    bool isdata = networkInfo.Type == ConnectivityType.Mobile;
                    if (!isOnline)
                    { StartActivity(typeof(InternetCheckingView)); }
                    else if(isWifi)
                    {
                        Toast.MakeText(_context, "Wifi Connected", ToastLength.Short).Show();
                    }
                    else if (isdata)
                    {
                        Toast.MakeText(_context, "Mobile Data Connected", ToastLength.Short).Show();
                        bool datatype = IsConnectionFast(subType);
                        if(!(datatype))
                        {StartActivity(typeof(InternetCheckingView));}
                    }
                }
            };
        }

        public bool IsConnectionFast(object networkType)
        {
            switch (subType)
            {
                //case TelephonyManager.NETWORK_TYPE_1xRTT:
                case NetworkType.OneXrtt:
                    return false; // ~ 50-100 kbps//case TelephonyManager.NETWORK_TYPE_CDMA:
                case NetworkType.Cdma:
                    return false; // ~ 14-64 kbps//case TelephonyManager.NETWORK_TYPE_EDGE:
                case NetworkType.Edge:
                    return false; // ~ 50-100 kbps//case TelephonyManager.NETWORK_TYPE_EVDO_0:
                case NetworkType.Evdo0:
                    return true; // ~ 400-1000 kbps //case TelephonyManager.NETWORK_TYPE_EVDO_A:
                case NetworkType.EvdoA:
                    return true; // ~ 600-1400 kbps//case TelephonyManager.NETWORK_TYPE_GPRS:
                case NetworkType.Gprs:
                    return false; // ~ 100 kbps//case TelephonyManager.NETWORK_TYPE_HSDPA:
                case NetworkType.Hsdpa:
                    return true; // ~ 2-14 Mbps//case TelephonyManager.NETWORK_TYPE_HSPA:
                case NetworkType.Hspa:
                    return true; // ~ 700-1700 kbps//case TelephonyManager.NETWORK_TYPE_HSUPA:
                case NetworkType.Hsupa:
                    return true; // ~ 1-23 Mbps//case TelephonyManager.NETWORK_TYPE_UMTS:
                case NetworkType.Umts:
                    return true; // ~ 400-7000 kbps
                                 /*
                                  * Above API level 7, make sure to set android:targetSdkVersion
                                  * to appropriate level to use these
                                  */
                                 //case TelephonyManager.NETWORK_TYPE_EHRPD: // API level 11
                case NetworkType.Ehrpd:
                    return true; // ~ 1-2 Mbps//case TelephonyManager.NETWORK_TYPE_EVDO_B: // API level 9
                case NetworkType.EvdoB:
                    return true; // ~ 5 Mbps//case TelephonyManager.NETWORK_TYPE_HSPAP: // API level 13
                case NetworkType.Hspap:
                    return true; // ~ 10-20 Mbps//case TelephonyManager.NETWORK_TYPE_IDEN: // API level 8
                case NetworkType.Iden:
                    return false; // ~25 kbps//case TelephonyManager.NETWORK_TYPE_LTE: // API level 11
                case NetworkType.Lte:
                    return true; // ~ 10+ Mbps// Unknown//case TelephonyManager.NETWORK_TYPE_UNKNOWN:
                case NetworkType.Unknown:
                    return false;
                default:
                    return false;
            }
        }

Here I would like to detect the slow network or not and if that is a slow network I have to call StartActivity(typeof(InternetCheckingView))

Can any one please help me to do that in I would like to open a popup whenever there is no data communication available like a onclicklisner in so that the even filers when ever there is a data loss even when the network is connected

(Added--)

I am checking for the data communication by pinging a url when the network connected change like disconnected or changes between wifi and mobile data but i would like to know the solution to get a popup to connect network whenever the data communication is lost even if it is connected to the network only when the app is opened.