Transport Service Providers

A given transport service provider supports one or more protocols. For example, a TCP/IP provider would supply (as a minimum) the TCP and UDP protocols, while an IPX/SPX provider might supply IPX, SPX, and SPX II. Each protocol supported by a particular provider is described by a WSAPROTOCOL_INFOW structure, and the total set of such structures can be thought of as the catalog of installed protocols. Applications can retrieve the contents of this catalog (see WSAEnumProtocols), and by examining the available WSAPROTOCOL_INFOW structures, discover the communications attributes associated with each protocol.