since v11.27

The extension point CallStateEventListener is a java interface that can be implemented to perform actions within the novomind iAGENT routing process after a call state has been changed.

All required information about the call is provided by the CallStateChangedEvent parameters, which are passed to the various method calls. If you don't need to distinguish the different close events you can just override the method with the CallStateChangedEvent parameter. Otherwise override the methods that suit your needs.