Host Connectivity and Windows 95

Host connectivity in this section refers to connecting to legacy IBM mainframe computers, the mid-range IBM AS/400® computers, DEC VAX®/VMS, UNIX, and HP® 3000 computers. Host terminal emulation applications running in Windows 95 require network protocols to connect to their respective hosts.

The common network protocols used to support host connectivity include the following:

• IPX/SPX. The IPX/SPX-compatible transport provided with Windows 95 is compatible with Novell NetWare IPX/SPX, and can be installed to support host connectivity using terminal emulation programs and gateways supporting an IPX/SPX interface.
• NetBEUI. The NetBEUI protocol provided with Windows 95 supports a NetBIOS programming interface and conforms to the IBM NetBEUI specifications. It also includes performance enhancements related to NetBIOS 3.0. Microsoft NetBEUI can be installed on computers running Windows 95 to provide NetBIOS support for host connectivity using terminal emulation programs and gateways supporting a NetBIOS interface.
• TCP/IP. The TCP/IP protocol provided with Windows 95 is a complete implementation of the most common and accepted protocol available. It allows connectivity between interconnected networks with different operating systems and hardware architectures such as UNIX, IBM mainframes, and Microsoft networks. Usually, host connectivity with the TCP/IP protocol is provided using Telnet services such as TN3270 connecting to legacy mainframes, TN5250 connecting to an IBM AS/400, and using gateways supporting a TCP/IP interface. Microsoft TCP/IP supports the Windows Sockets 1.1 interface.
• DLC. Data Link Control (DLC) protocol is used primarily to access IBM mainframe computers. This protocol is not used for general networking with Windows 95. Host terminal emulation programs use this protocol directly to communicate with IBM mainframe computers.

For information about using Microsoft NetBEUI, the IPX/SPX-compatible protocol, and TCP/IP, see Chapter 12, "Network Technical Discussion."

Windows 95 includes a real-mode version of the DLC protocol. This section discusses how to install the Microsoft DLC protocol for host connectivity, and how Windows 95 upgrades over existing DLC configurations. This section also provides tips for using terminal emulation applications and connectivity through gateways.