Glossary of Data Communications TermsCourtesy Enterprise-Wide Computing, Inc. |
Term:
Systems Network Architecture (SNA)
Definition: IBM network architecture, defined in terms of its functions, formats and protocols. A widely used communications framework developed by IBM to define network functions and establish standards for enabling computers to exchange and process data. SNA is a layered network architecture consisting of the following seven layers (numbered from lowest [1] to highest [7]): (1) Physical Control Layer; (2) Data Link Control Layer; (3) Path Control Layer; (4) Transmission Control Layer; (5) Data Flow Control Layer; (6) Presentation Services Layer; (7) Transaction Services Layer. An SNA network is that part of a user-application network that conforms to the formats and protocols of Systems Network Architecture. It enables reliable transfer of data among end users and provides protocols for controlling the resources of various network configurations. The SNA network consists of network accessibl units (NAUs), boundary function, gateway function, and intermediate session routing function components; and the transport network. |