Definitions for "Direct Distance Dialing"
Keywords:  ddd, iddd, telephone, distance, dial
(DDD) A telephone service with which a subscriber can call someone outside the area without requiring operator assistance.
Telephone exchange service that enables the telephone user to call long distances without operator assistance.
(DDD) A telephone service which enables a user to dial long distance calls directly to telephone outside the user's local service area without the aid of an operator.