Open Source - How To Conference with Digium Phones
For standard D-Series Phones:
During a call, press the Conference softkey. Make a call, or Resume an existing call.
Press Conference again to connect all participants.
To end the Conference and put both calls on Hold, press the Split softkey on either call.
For D-80 model phones:
During a call tap Conference.
Dial the third participants number, or select from Contacts.
Tap Complete to connect all participants.
Tap Split to separate calls with each participant.