Systems Network Architecture

Systems Network Architecture (SNA) is IBM's proprietary networking architecture created in 1974. It is a complete protocol stack for interconnecting computers and their resources. SNA is still used intensively in banks and other financial transaction networks.

Within SNA there are two types of datastream to connect local terminals and printers; there is the 3270 datastream mainly used by mainframes (S/390 family) and the 5250 datastream mainly used by minicomputers/servers such as the S/36, S/38, and AS/400 (nowadays called the iSeries).

Starting from version 5.2 of OS/400, SNA for