title: Async socket server with multiple clients connected
body: <p>I want to write a asynchronous socket server and client in C#. The server has to manage many client connections and keep them alive as long as it's possible.
  I tried using MSDN server code <a href="http://msdn.microsoft.com/en-us/library/fx6588te%28v=vs.110%29.aspx" rel="nofollow">from this site</a>, but it cant handle multiple clients at the same time and closes connection after sending acknowledge message. Could you show me how I'm supposed to change that example code to manage sending messages to many clients at the same time (like, having client connections in some array or list) and keeping the connection alive?</p>