Winsock SPI

The Winsock Service Provider Interface, or Winsock SPI, is a specialized discipline of Winsock used to create providers; transport providers such as TCP/IP or IPX/SPX protocol stacks use the Winsock SPI, as do namespace providers such as the Internet's Domain Naming System (DNS).

Traditional network programming, such as enabling applications to communicate over the network, does not require use of Winsock SPI interfaces; use standard Winsock interfaces instead.


The Winsock SPI uses the following function prefix naming convention.

Prefix Meaning Description
WSP Windows Sockets Service Provider Transport service provider entry points
WPU Windows Sockets Provider Upcall Ws2_32.dll entry points for service providers
WSC Windows Sockets Configuration WS2_32.dll entry points for installation applets
NSP Namespace Provider Namespace provider entry points