On this day, 31 years ago, on October 22, 1994 (September 18, 1994 in the lunar calendar), China's public digital data network was opened. On October 22, 1994, China Public Digital Data Network (CHINADDN) was officially completed and opened. At present, the network can reach 21 municipalities and provincial capitals, and can provide 776 high-speed circuits at 2.048Mbps and 2588 circuits at other speeds. Digital data networks in 16 provinces and 17 cities have been opened for service, and are expected to cover more than 300 cities across the country in the first half of next year. This network and the China Public Packet Switched Data Network, which was opened a year ago, will be interconnected with computer networks and information systems of various sectors of society to form a public information network with rich resources and complete functions, including man-machine communications and computer communications, and will provide communication services for the establishment of various national information processing systems.