When referring to the seven layers of the OSI model for network communications, Windows Sockets functions at the session layer interface to the transport layer. In other words, Windows Sockets is an interface between applications and the transport protocol and works as a bi-directional pipe for incoming and outgoing application data. Windows Sockets is implemented as a dynamic-link library (DLL) that allows applications and the transport service to be dynamically bound together at run time.
Windows Sockets was originally designed for use with the TCP/IP transport protocol. However, extensions to Windows Sockets now allow use of non-TCP/IP transport protocols with Windows Sockets. Windows Sockets as implemented in Windows NT Server and Windows NT Workstation provides a true transport-independent interprocess communication service. Windows Sockets in Windows NT Server and Windows NT Workstation supports the following transport protocols:
Note
Windows NT Server and Windows NT Workstation version 4.0 implement 32-bit Windows Sockets version 2.0. Earlier versions of Windows NT implement 32-bit Windows Sockets version 1.1. The specifications for Windows Sockets are open, public specifications. See the section "Developing Programs Using Windows Sockets" at the end of this appendix for a list of Microsoft and other Internet sites from which you can receive information about Windows Sockets.
TCP/IP Utilities Compatible with Windows Sockets
As mentioned earlier, Windows Sockets was originally designed for use with TCP/IP. Many commonly used TCP/IP utilities are compatible with the Windows Sockets provided with Windows NT Server and Windows NT Workstation. These TCP/IP utilities are as follows:
For a complete description of each of these utilities, see online Help or refer to Appendix A, "TCP/IP Utilities Reference."