Organizations with IBM® mainframe or AS/400® computers are consolidating their SNA-only and non-SNA networks into single TCP/IP-based wide area networks (WANs). In the past, two parallel networking systems have been deployed in most organizations: the traditional SNA network, used to connect PCs and hardware controllers with IBM mainframes and AS/400s, and local area networks (LANs), used primarily to access files and client/server applications running on local server computers.
In the past few years, there has been a dramatic increase in the number of organizations seeking a single WAN solution that provides access to all desktops, servers, and host systems across a single networking protocol. At the same time, TCP/IP is emerging as the protocol of choice because of its versatility, openness, and ability to support Internet and intranet connections.
Many organizations cannot integrate their networks because of the need to ensure reliable and secure access to existing IBM host systems — on which most organizations base their mission-critical daily operations.
SNA Open Gateway Architecture (SOGA) satisfies the requirement for reliable and secure host connectivity in the context of an integrated WAN. SOGA is a scalable framework for SNA enterprise connectivity, offering multiple options for integrating branch offices by means of routed internetworks with IBM mainframe and AS/400 computers. This framework encompasses components from leading channel attachment and internetworking vendors, while deploying SNA Server computers in both traditional and innovative ways.
SOGA supports industry standards for SNA host access and presents flexible options for integrating host data across open WANs, such as those composed of Data Link Switching (DLSw), Frame Relay (RFC 1490), and Asynchronous Transfer Mode (ATM). Request for Comment (RFC) 1490 specifies methods of encapsulating TCP/IP and SNA within Frame Relay. The SOGA blueprint consists of three core elements: