Multiple-Way Call - D-Link DPH-400S User Manual

3. When the call is answered, press Conf and add the first call to the
conference.
4. If you want to release the conference, press Split key.

3.10 Multiple-way call

If user has 4 line calls and wants to invite the five party during the call, they can
press Conf or Transf "New Call", press OK, enter the number ,then press Send
and wait for the other party to answer. When the multiple-way calls, you can
press the arrow keys to select a call.