EXPRESS SNA Server

The architecture of EXPRESS SNA Server comprises several key components designed to facilitate SNA communication. The SNA Gateway is the core component, responsible for protocol conversion between TCP/IP and SNA. The Communication Manager handles network connections and session management, utilizing TCP/IP for transport.

The Application Interface provides a means for UNIX-based applications to interact with SNA resources. 1 emulation, enabling it to connect to a wide range of SNA hosts. Configuration files, located in the `/etc/sna` directory, define SNA nodes, link stations, and logical units.

The `snaconfig` utility is used to manage these configurations. The server does not use a database for persistent storage; configuration data is stored in text-based files. The server listens on configurable ports for incoming SNA connections.

The SNA Gateway translates between TCP/IP and SNA protocols, handling session establishment, data transfer, and session termination. The Communication Manager manages the underlying network connections, ensuring reliable data transmission. The Application Interface provides a set of APIs for developers to build applications that interact with SNA resources.

The server's design prioritizes efficient SNA protocol handling and seamless integration with UNIX environments. The server's architecture is focused on providing a dedicated SNA gateway, unlike some competitors that offer broader networking solutions.