Consolidating SNA onto IP is not a simple task. Each set of SNA components and applications should be evaluated on its own merits, and a solution should be found that best suits the requirements. In some cases a solution is to replace an application or device; in other cases it is to use data link switching (DLSw), SNA switching services (SNASw), branch extender (BEX), Enterprise Extender, or a combination of these.

DLSw is a common SNA over IP solution found in the wide area networks (WANs) of many organizations. The DLSw router is deployed at branch offices and peered to data center DLSw routers. Upstream to the z/OS mainframe is normally through SNASw routers and OSA-Express. DLSw provides switching at the data link layer (layer 2), and encapsulates SNA into TCP packets for transportation through the WAN.

Enterprise Extender is an extension of SNA high performance routing (HPR) and provides encapsulation of SNA packets into UDP frames at the edges of an IP network.

Enterprise Extender capable devices and components include: z/OS Communications Server, Cisco routers, Microsoft Host Integration Server and IBM Communications Server for Windows and AIX, and IBM Personal Communications for Windows.

SNASw branch extender support within the above components can be deployed at the branch office, and connects directly to Enterprise Extender on z/OS through an organization's IP router network.

SNA views Enterprise Extender as just another data link control, while IP views Enterprise Extender as a UDP application. No changes are required to the SNA applications if Enterprise Extender is deployed.

Core z/OS enablement definitions are contained in VTAM, but also requires TCP/IP setup. A routing protocol such as OSPF, although it has no Enterprise Extender-specific definitions, is required to provide a high availability IP routing solution.