Following guide walks through making a 3-way call.
Pick up your handset or press the speaker button to get a dial tone.
Call the extension or phone number of your first conference call attendee. After they pick up the phone, ask them to hold on while you contact the other attendees.
Press the Conference button your phone, then you should hear a dial tone, Dial the number of your second attendee.
When the second attendee pucks up, press the Conference button again to join your calls together.