Telephone system preventing anonymous calling - uses sender transmitting subscriber's number to called extension for display and acknowledgement before handset can be used

摘要: The telephone system has a caller identification facility. After dialling the required extension, sender of calling extension transmits its own number to called extension. is stored i store and displayed. Only after been received connection subscriber completed. This arrangement affords protection against anonymous nuisance callers. can be switched in by release button. display made l.e.d.s.