This feature will allow you to set up the feature in which an extension automatically calls you back if they are busy when you call them. 

Conditions that need to be met in order for this to work: 

  1. You have to have call waiting disabled
  2. You have to have call forwarding disabled on the extension
  3. You have to have a busy message recorded via the *85 feature code
  4. You need to be on a call for this feature to work (Does not work for no answer, only busy)

Once all these conditions have been met in order to schedule a call back you would dial the extension and if they are on a call you can dial "0". 

This will then schedule the extension to call you back on your extension as soon as they're done with their call.