HOW TO PLACE A CONFERENCE CALL
You may conference up to five parties (you and four others) in any combination of outside lines and/or internal stations in any order.
If you are not able to reach the desired person when attempting to add another party to the conference, hang up. Then press the [CONF] key again to return to your previous conversation.
To leave the conference, hang up. Control is passed to the next internal station.
How to place a conference call.