The Windows Sockets 2 specification is a superset of the widely deployed Windows Sockets 1.1 interface. While maintaining full backward compatibility, it extends the Windows Sockets interface in a number of areas, including providing access to protocols other than TCP/IP. Windows Sockets allows an application to use the familiar socket interface to achieve simultaneous access to any number of installed transport protocols.
While most of these protocols' facilities may be used with standard Windows Sockets 2 interface mechanisms, each supported protocol has certain conventions and behaviors which developers may need to become aware of. Also, individual protocols support special features that do not lend themselves to being treated generically. The purpose of this document is to provide the details necessary for developers to effectively use any of the supported protocols.