Using TCP/IP with Third-Party Software

TCP/IP is a common denominator for heterogeneous networking, and Windows Sockets is a standard used by application developers. Together they provide a framework for cross-platform client-server development. TCP/IP-aware applications from vendors that comply with the Windows Sockets standards can run over virtually any TCP/IP implementation.

The Windows Sockets standard ensures compatibility with Windows-based TCP/IP utilities developed by more than 30 vendors. This includes third-party applications for the X Window System, sophisticated terminal emulation software, NFS, electronic mail packages, and more. Because Windows NT offers compatibility with 16-bit Windows Sockets, applications created for Windows 3.x Windows Sockets run over Windows NT without modification or recompilation.

For example, third-party applications for X Window provide strong connectivity solutions by means of X Window servers, database servers, and terminal emulation. With such applications, a Windows NT computer can work as an X Window server platform while retaining compatibility with applications created for Windows NT, Windows 3.1, and MS-DOS on the same system. Other third-party software includes X Window client libraries for Windows NT, which allow developers to write X Window client applications on Windows NT that can be run and displayed remotely on X Window server systems.

The Windows Sockets API is a networking API used by programmers creating applications for both the Microsoft Windows NT and Windows operating systems. Windows Sockets is an open standard that is part of the Microsoft Windows Open System Architecture (WOSA) initiative. It is a public specification based on Berkeley UNIX sockets, which means that UNIX applications can be quickly ported to Microsoft Windows and Windows NT. Windows Sockets provides a single standard programming interface supported by all the major vendors implementing TCP/IP for Windows systems.

The Windows NT TCP/IP utilities use Windows Sockets, as do 32-bit TCP/IP applications developed by third parties. Windows NT also uses the Windows Sockets interface to support Services for Macintosh and IPX/SPX in NWLink. Under Windows NT, 16-bit Windows-based applications created under the Windows Sockets standard will run without modification or recompilation. Most TCP/IP users will use programs that comply with the Windows Sockets standard, such as ftp or telnet or third-party applications.

The Windows Sockets standard allows a developer to create an application with a single common interface and a single executable that can run over many of the TCP/IP implementations provided by vendors. The goals for Windows Sockets are the following:

• Provide a familiar networking API to programmers using Windows NT, Windows for Workgroups, or UNIX
• Offer binary compatibility between vendors for heterogeneous Windows-based TCP/IP stacks and utilities
• Support both connection-oriented and connectionless protocols

Typical Windows Sockets applications include graphic connectivity utilities, terminal emulation software, Simple Mail Transfer Protocol (SMTP) and electronic mail clients, network printing utilities, SQL client applications, and corporate client-server applications.

If you are interested in developing a Windows Sockets application, specifications for Windows Sockets are available on the Internet from ftp.microsoft.com, on CompuServe® in the MSL library, and in the Microsoft Win32 Software Developers Kit.

To get a copy of the Windows Sockets specification via anonymous FTP

1. Make sure you have write permission in your current working directory.
2. At the command prompt, start ftp, and then connect to ftp.microsoft.com (or 198.105.232.1).
3. Log on as anonymous.
4. Type your electronic mail address for the password.
5. Type cd \advsys\winsock\spec11, and then press ENTER.
6. Use the dir command to see the list of available file types. If you want binary data such as in the Microsoft Word version, type bin, and then press ENTER.
7. Determine the file with the format you want [for example, ASCII (.TXT), PostScript® (.PS), or Microsoft Word (.DOC)], and then type get winsock.ext where ext is the format that you want, such as winsock.doc for the Microsoft Word version.

To get a copy of the Windows Sockets specification from CompuServe

1. At the command prompt, type go msl, and then press ENTER.
2. Browse using the keywords windows sockets.
3. Choose the file with the format you want [ASCII (.TXT), PostScript (.PS), or Microsoft Word for Windows (.DOC)], and then type get winsock.ext.

There is also an electronic mailing list designed for discussion of Windows Sockets programming.

To subscribe to the Windows Sockets mailing list

• Send electronic mail to listserv@sunsite.unc.edu with a message body that contains subscribe winsock user's-email-address.

You can use the same procedure to subscribe to two mailing lists called winsock-hackers and winsock-users.