title: Why can't I reference System.Net.Sockets in a Portable Class Library using Xamarin?
body: <p>I am trying to use System.Net.Sockets API in a portable class library so that my projects can reuse code for socket connections. But I cannot reference that namespace in my code. </p>
  
  <p>As I understand it, PCLs limit you to assemblies that are available on all targeted platforms. But I am targeting ios, Android, and .Net 4.5 (using Xamarin), and all of these should have the system.dll assembly that contains the API. What am I missing?</p>