The conventional Logical Unit Application (LUA) programming interface is an API that allows you to write logical unit applications to communicate with host applications. The interface is provided at the request/response unit (RU) and session levels, allowing programmable control over the Systems Network Architecture (SNA) messages sent between your communications software and the host. It can be used to communicate with any of the logical unit (LU) types 0, 1, 2, or 3 at the host; it is up to the application you develop to send the appropriate SNA messages required by the host.
The Microsoft® SNA Server implementation of LUA is compatible with the Request Unit Interface (RUI) and the Session Level Interface (SLI) of LUA for the Microsoft® Windows NT® operating system, the Microsoft Windows® graphical environment, and the IBM Extended Services for OS/2 version 1.0 (IBM ES for OS/2 version 1.0) operating system.
The following topics provide a conceptual overview of LUA and discuss important programming considerations. For more information about these topics, see the Microsoft SNA Server documentation in the "Internet, Networking, and Distributed Services" section of the Microsoft Platform SDK.