System Network Architecture (SNA) is a set of IBM mainframe network protocols that were established in 1974 with the aim of connecting various devices to a central host computer. Originally designed as a centralized architecture, SNA later evolved to adjust to contemporary peer-to-peer communications and distributed computing environments.
Today, SNA is used mainly in legacy systems while TCP/IP has become the dominant protocol for modern networks. However, understanding the basic ideas behind SNA remains important for professionals working with mainframe systems. Some key features of SNA include:
APPN and APPC (LU 6.2)
APPN and APPC (LU 6.2) are protocols that expanded the capabilities of SNA and enabled it to work with contemporary computing environments. APPN (Advanced Peer-to-Peer Networking) allowed for peer-to-peer communication over SNA, while APPC (Advanced Program-to-Program Communication) allowed for communication between applications on different systems.
Centralized Architecture
SNA was originally designed as a centralized architecture where a host computer controlled numerous terminals. The host computer communicates with the terminals through a cluster controller that manages the terminals and provides a single point of communication.
Legacy System
While TCP/IP has largely replaced SNA in modern networks, SNA remains an important part of legacy systems, particularly those that still use IBM mainframes. Understanding SNA can help professionals work with these legacy systems and potentially migrate them to modern architectures.
FAQs About System Network Architecture
What is System Network Architecture (SNA)?
SNA is a set of IBM mainframe network protocols that were established in 1974 to connect various devices to a central host computer.
What are APPN and APPC (LU 6.2)?
APPN and APPC (LU 6.2) are protocols that expanded the capabilities of SNA and enabled it to work with contemporary computing environments. APPN allowed for peer-to-peer communication over SNA, while APPC allowed for communication between applications on different systems.
Is SNA still used?
SNA is still used in legacy systems, particularly those that still use IBM mainframes. However, TCP/IP has largely replaced SNA in modern networks.
Final Thoughts
System Network Architecture (SNA) may have been replaced by TCP/IP as the dominant protocol for modern networks, but understanding the basic ideas behind SNA remains important for professionals working with mainframe systems. Features like APPN and APPC have expanded the capabilities of SNA, and it continues to be an important part of legacy systems today.
