Core Issue
The Call Park feature allows you to place a call on hold so it can be retrieved from another phone in the Cisco CallManager system (for example, a phone in another office or in a conference room). If you are on an active call at your phone, you can park the call to a call park extension by pressing the Park softkey or the Call Park button. Someone on another phone in your system can then dial the call park extension to retrieve the call.
You can define either a single directory number or a range of directory numbers for use as call park extension numbers.
Resolution
For information on configuring Call Park, refer to these sections of Call Park: