SNA Enhancements for Distributed Data Processing

Abstract

Systems Network Architecture (SNA) defines the behavior of networks of heterogeneous, loosely coupled processors. After a brief introduction of SNA, this paper describes three recent enhancements to SNA which will further increase the capabilities of SNA products and users to interact in distributed data processing system environments.The first enhancement allows applications in different, independent SNA networks to communicate with one another without having to be modified. In fact, after installation of this Network Interconnection function, a user need not be aware that the session partner is in a separate network.The second enhancement is the definition of a general-purpose program-to-program protocol that serves as a base for future application programs cooperating in a distributed system environment. This Advanced Program-to-Program Communication (APPC) interface also serves as a foundation upon which additional distribution services can be provided by IBM, other suppliers of hardware and software, and owners of individual networks.The third enhancement provides a general asynchronous (i.e., queued) data distribution facility for all applications needing such a service, e.g., office systems, file transfer, job networking, and network management. SNA Distribution Services (SNADS) are provided by a set of architected service transaction programs using APPC.