Since 1997, Power Plug has been developing 4D-based management systems for CTI (Computer Telephony Integration), inventory, accounting and products. The CTI system connects to Asterisk PBX to interface with and control external IP phones. Two-channel display and three-way control are possible, and customer databases can be accessed on the web site for CTI to look up customer information. The system can judge the responses from receivers automatically, saving time and effort for telephone operators until the beginning of a conversation. Power Plug also provides calling services for the elderly.