title: What is the difference between DefaultAppPool and Classic .NET AppPool in IIS7?
body: <p>I have a problem with timeouts in IIS. In the web.config the session timeout was set to 60 minutes but after 20 minutes the session ends. </p>
  
  <p>This problem only occurs in IIS7 and not in IIS5.</p>
  
  <p>After some investigation, I discovered it was due to the application pool's timeout. If the App Pool is left 20 minutes without doing anything, IIS ends the session.</p>
  
  <p>If the application is using the defaultAppPool this always happens but if I change the App Pool to the classic .NET App Pool, the timeout does not occur.</p>
  
  <p>Both modes have idle timeout but <em>only</em> in the DefaultAppPool this occurs.</p>
  
  <ul>
  <li>Why is this? </li>
  <li>What is the difference between be a Classic .NET AppPool and DefaultAppPool?</li>
  <li>What is the difference in the pipeline, between Classic and Integrated?</li>
  </ul>