Charge minimizing callback system

摘要

A device and method minimize telephone charges by not answering the destination telephone when an incoming call is detected. Preconnection information such as dialed number identification system (DNIS) information, phone type information digits, and automatic number identification (ANI) information is automatically provided by the public switched telephone network to the destination telephone in response to the incoming call. The preconnection information is examined to determine if the rate structure is such that it would be more desirable to have the call billed as if it originated from the destination telephone or from the source telephone. If it is less expensive to have the call originate from the source telephone, the call is answered. If it is less expensive to have the call originate from the destination phone, a signal is sent to the user prompting them to hang up. When the caller hangs up, a return call is placed to the number and the caller answers. A slight modification of the method and device can be utilized to operate a cost efficient calling card system. The preconnection information is received at a central station without answering the telephone and a return call is placed. The caller then enters the number they wish to call. The central station then connects the caller to the number. In accordance with the invention, callers can also be prompted to enter an identification code to insure they are authorized to use the system.