- Click on the Extension Manager menu item.
- Click on the Extension sub-menu item.
- Select the correct extension.
- Click on the Options tab at the top.
- Ensure Call forwarding is disabled.
- Ensure Call waiting is disabled.
- Ensure a busy message is recorded via the *85 feature code.
You need to be on a call for this feature to work (It does not work for no answer, only busy)
Once all these conditions have been met, dial the extension. If they are on a call can dial "0".