Systems Network Architecture (SNA)

Definition

Systems Network Architecture (SNA) is a proprietary networking architecture developed by IBM in 1974. It was designed to ensure reliable and efficient communication between IBM mainframes and peripherals such as terminals, printers, and storage devices. The architecture provides a complex set of protocols, enabling diverse systems to communicate over both local and wide-area networks (LANs and WANs). SNA integrates a suite of higher-level services to streamline network design and management, including communication control, data synchronization, and error correction.

Examples

1. Enterprise Mainframe Network: SNA is often used in large corporations relying on IBM mainframe systems for handling massive transactional data processing. For instance, banks may use SNA for secure and reliable financial transaction processing across various branches.

2. Retail Systems: Many retail companies implement SNA to manage point-of-sale (POS) systems networking with centralized inventory and accounting applications on mainframe systems.

3. Government Organization Networks: Government agencies that have legacy IBM systems still use SNA for the operation of crucial applications and records management systems over vast geographical areas.

Frequently Asked Questions (FAQs)

What are the primary layers in Systems Network Architecture?

SNA is structured into seven layers, somewhat analogous to the OSI model. The layers include:

1. Physical control (PC): Defines hardware and transmission media.
2. Data link control (DLC): Manages point-to-point data streams.
3. Path control (PC): Handles routing and path determination.
4. Transmission control (TC): Ensures data flows reliably and in the correct sequence.
5. Data flow control (DFC): Manages the pacing and timing of message units.
6. Presentation control (PSC): Transforms application data formats.
7. Transaction services (TS): Supports application processes.

Can SNA be integrated with modern networking protocols?

Yes, SNA has been adapted over the years to interoperate with modern networking protocols such as TCP/IP, often through the use of gateways, routers, and middleware that translate SNA communications into protocols compatible with contemporary systems.

Is SNA still in use today?

While SNA usage has declined in favor of TCP/IP and other modern networking protocols, it is still in use in many legacy systems, particularly within sectors like banking, retail, and government that rely on IBM mainframes.

Related Terms

• Mainframe: Large, powerful computers primarily used for large-scale computing purposes such as bulk data processing.
• TCP/IP: A suite of communication protocols used to interconnect network devices on the internet.
• Middleware: Software that acts as a bridge between an operating system or database and applications, especially on a network.
• Protocol: A set of rules governing the exchange or transmission of data between devices.

Online References

1. IBM SNA Overview
2. Wikipedia - Systems Network Architecture
3. IBM Knowledge Center

Suggested Books for Further Studies

1. “IBM’s Systems Network Architecture: Architecture and Concepts” by Wolfgang F. Syrůček
2. “IBM’s Systems Network Architecture: Enterprise Networks and Protocols” by Hidetaka Fukuhara and Toshio Takeshima
3. “Computer Networks” by Andrew S. Tanenbaum and David J. Wetherall

Fundamentals of Systems Network Architecture: Networking Basics Quiz

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