This standard specifies the technical requirements for the main business performance, call processing functions, numbering, signaling, billing, and traffic statistics of digital program-controlled automatic telephone exchanges for office use. It also specifies the technical requirements for network synchronization, overload control, maintenance management, technical indicators, and network management that is being developed. This standard applies to the development, design, inspection, and acceptance of various digital program-controlled automatic telephone exchanges in the national public long-distance telephone network and local telephone network. GB/T 15542-1995 Technical Requirements for Digital Program-Controlled Automatic Telephone Exchanges GB/T15542-1995 Standard Download Decompression Password: www.bzxz.net