title: WCF: DuplexChannelFactory timeout error
body: <p>I'm using a DuplexChannelFactory when accessing my WCF service so that my service can use a callBackChannel to communicate back to the client.</p>
  
  <p>That's all fine but I get a timeout error when creating the CallBackChannel if I do not use the channel for a period of time. I create the callBackChannel like so:</p>
  
  <pre><code>OperationContext.Current.GetCallbackChannel&lt;ICallBack&gt;().MethodOnClient();
  </code></pre>
  
  <p>Does anyone know how to change the timeout to infinity and what the actually default timeout period is?</p>