A customer premises communications system that provides its station subscribers with a wide variety of telephony services and access to public switched telephone network (PSTN) trunk circuits provided by local exchange carrier (LEC) and interexchange carrier (IEC) services. Standard private branch exchange (PBX) system hardware elements include the common equipment (cabinets, shelf carriers, printed circuit boards) and telephone instruments. Peripheral servers may also be included in the system design configuration to support systems management and voice messaging requirements. A PBX system is privately owned and physically located at the user subscriber's premises. Telephony services provided by a PBX range from basic communications operations (provisioning of dial tone and switched connections between peripheral endpoints) to station user-controlled call processing features (such as call transfer, call forwarding, and call waiting) to advanced software applications (such as multisystem networking and call contact centers).