You can connect to an IBM mainframe via a Microsoft SNA Server. A Microsoft SNA Server connection supports the complete range of terminal and printer types, on single or multiple hosts, and IND$FILE transfer.
Microsoft SNA Client software running on each client workstation.
TCP/IP transport protocol, installed on the SNA Server and on the client workstations.
If you need the Microsoft SNA client software, you can obtain it from the Microsoft SNA Server or Host Integration Server CD or directly from Microsoft. It is recommended that the client software match the SNA Server or Host Integration Server version installed.The SNA Server client software is not required for TN3270 or TN5250 connections to a Microsoft SNA Server or Host Integration Server.