SYSTEMS NETWORK ARCHITECTURE - OVERVIEW

A method to unify network operations, known as Systems Network Architecture (SNA), is discussed. SNA increases network flexibility by clearly identifying and separating the functional responsibilities of three major functional layers: transmission management; function management; and application. A key concept of SNA is the structuring of each network node as a set of well-defined layers. SNA defines an orderly flow of information between an application program in a host and either a terminal user or another application program. To facilitate this communication and ease application program development, an SNA network insulates end users from the details of network operation. An end user need only be aware of the protocols and data formats required for interaction with function management in his node. The products developed for use in SNA networks are combinations of hardware and programming whose design is based on the architecture. Using some current implementations as examples, this overview introduces the concepts on which the architecture is based and broadly describes the basic components of the structure.