How to collect internet usage information for iPhone with Xamarin / monotouch

Question

I need to collect internet usage information on iphone , the code c# below that I am using only returns me zeroed values.

I’m using the right class ?

has some reference I need to add on Xamarin ?

in the mono appears me 3 types of classes , concidently the interface "Macosipv4interfacstatics" returns fixed always the value 0.

https://github.com/mono/mono/blob/master/mcs/class/System/System.Net.NetworkInformation/IPv4InterfaceStatistics.cs

1. Win32ipv4interfacstatics
2. Linuxipv4interfacestatistics

3. Macosipv4interfacstatics

   using System;
   using System.Net;
   using System.Net.NetworkInformation;
   using System.Runtime.InteropServices;
   using System.Threading;
   using MonoTouch.ObjCRuntime;
   

   namespace Taximetro { public delegate void Update();

   public static class ControleUso
   {
       public static long controller;
   
       public static long BytesReceivedWiFi;
       public static long BytesSentWiFi;
   
       public static long BytesReceived3G;
       public static long BytesSent3G;
   
       public static Update UpdateMethod;
   
       public static void DoWork()
       {    
           foreach (var netint in NetworkInterface.GetAllNetworkInterfaces()) {
               var stats = netint.GetIPv4Statistics ();
   
               //WiFi
               //if (netint.Name.StartsWith ("en")) {
                   BytesReceivedWiFi += stats.BytesReceived;
                   BytesSentWiFi += stats.BytesSent;
               //}
   
               //3G
               if (netint.Name.StartsWith ("pdp_ip")) {
                   BytesReceived3G += stats.BytesReceived;
                   BytesSent3G += stats.BytesSent;
               }
           }
           controller++;
           if (UpdateMethod != null) {
               UpdateMethod ();
           }
           Thread.Sleep (1000);
       }
   }
   

   }