In the hierarchical SNA network model most frequently associated with mainframes, centralized applications are accessed from remote terminals across a network..
This model uses the information display protocol for IBM mainframe computers known as 3270. This protocol facilitates conversations between the mainframe and devices such as terminals, printers, and controllers. Through the definition and assignment of 3270 logical units, SNA Server provides access to these mainframe resources.
Once you have established the physical connection from SNA Server to the mainframe, you need to determine the types of 3270 connectivity that your users need. This chapter discusses the services that SNA Server can provide to your users and suggests ways to set up these services.