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SNA Terms and Concepts

Basic SNA Concepts

Basic SNA Concepts

SNA defines the standards, protocols, and functions used by devices—from mainframes to terminals—to enable them to communicate with each other in SNA networks.

SNA functions are divided into a hierarchical structure of separate layers, each performing a specific set of functions. This division of network functions into layers enables network devices to share information and processing resources without having detailed information about each device on the network. A user at a workstation can communicate with another user without knowing anything about the physical devices on the network or the connections between those devices.

Network Types

SNA supports the following types of networks:

•A subarea network is a hierarchically organized network consisting of subarea nodes and peripheral nodes. Subarea nodes, such as hosts and communication controllers, handle general network routing. Peripheral nodes, such as terminals, attach to the network without awareness of general network routing.

•A peer network is a cooperatively organized network consisting of peer nodes that all participate in general network routing.

•A mixed network is a network that supports both host-controlled communications and peer communications.

HP-UX workstations running SNAplus2 can be part of a subarea network, a peer network, or both.

SNA Nodes

In SNA networks, a node is a system, workstation, or other device—with associated software components—that implements SNA protocols and has at least one communication path to another node in the network.

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Chapter 1