X·25广域数据网通信,在北美、西欧、日本等国外发达地区已有十多年广泛应用的历史,而在国内则是近几年才开始引进和推广。本文介绍了X·25网络通信的原理与协议、X·25网络通信的特点和网络提供的业务,并介绍了作者参与开发的X·25终端通信产品及X·25网络应用的前景。 X.25 wide area data network communication has been widely used for over a decade in developed countries such as North America, Western Europe and Japan. However, it has been introduced and promoted only in recent years in China. This paper introduces the principles and protocols of X.25 network communication, the characteristics of X.25 network communication and the services provided by the network, and introduces the prospect of X.25 terminal communication products and X.25 network applications that the authors participated in.