A growing trend in many types of enterprises is downsizing mainframe-based applications to run on personal computer client-server networks. Many of these downsized applications will still require access to data and applications residing on IBM System Network Architecture (SNA) hosts, mainframes and midrange computers. Companies have invested large amounts of money, time, and effort in their host systems and so want to be able to make the best use of that investment even as they move toward distributed client-server computing. This section discusses how Windows NT computers can be connected to IBM SNA hosts to leverage the high capacity of SNA hosts in a distributed environment.