System.Net.WebRequest on Xbox One?

Hi.

When I tried to call our Web API by POST method using following code:

 HttpWebRequest httpRequest = (HttpWebRequest)WebRequest.Create(url);

I got an error on debug output like this:

 NotSupportedException: http://192.168.***.***:****/***
   at System.Net.WebRequest.GetCreator (System.String prefix) [0x00000] in <filename unknown>:0 
   at System.Net.WebRequest.Create (System.Uri requestUri) [0x00000] in <filename unknown>:0 
   at System.Net.WebRequest.Create (System.String requestUriString) [0x00000] in <filename unknown>:0 

WebRequest is not supported on Xbox One? Or is there any way to enable it?

The WebRequest works great on iOS and Android platforms. http://docs.unity3d.com/410/Documentation/ScriptReference/MonoCompatibility.html

Thanks in advance.