Telephone interface call processing system with call selectivity

摘要

For use with a public telephone network CO incorporating a vast number of terminals T1-Tn, a system CS limits and controls interface access to implement voice-digital communication for statistical processing. The system CS accommodates calls in different modes, e. g. "800", "900" or area code and incorporates qualifying apparatus to restrict against caller misuse. Alternative calling modes are used to reach an interface facility that also affords some control based on calling terminal identification, e. g. as by ANI equipment.