Alternatives for providing highly reliable access to X.25 networks

Public and private packet-switching networks (PSNs) are being developed or planned throughout the world—for example in Canada (DATAPAC), the U.S. (TELENET), France (TRANSPAC), the U.K. (EPSS), Japan (DDX), Spain, Netherlands and others. 7 Such an explosive development of data communications services is one of the means for attaining the near-perfect availability required from future distributed information processing systems. 9 The reasons for this requirement are the increasing size, complexity and geographic dispersion of information processing systems, and the increasing real-time dependence of users on these critical, distributed systems for the timely and effective operation of their businesses.