一 DPABX在办公室系统中的地位随着社会的发展,人们越来越清醒地意识到,消息闭塞就等于落后,甚至会走向消亡;随着计算机的广泛使用,人们越来越深刻地认识到必须迅速改变单机使用的状况——这就要求建立人—机,机—机,人—人之间的广泛地信息传输和交换。为完成这一时代重托,综合业务数据网(ISDN)的概念应运而生。经过十多年来的理论研究和实践,建立ISDN的工作已有长足的进展。然而,无论技术上还是工程实现,ISDN都是艰 The Position of DPABX in the Office System With the development of society, people are more and more aware that information blockage is equal to falling behind or even disappearing. With the widespread use of computers, people have become more and more aware of the necessity Rapid changes in the status of stand-alone use - which requires the establishment of a wide range of information transfer and exchange between people, machines, machines and people. To fulfill this era of trust, the concept of Integrated Services Digital Network (ISDN) came into being. After more than a decade of theoretical research and practice, there has been considerable progress in establishing ISDN. However, ISDN is hard both technically and engineeringly