Winsock Service Provider Interface (SPI)
Following the Windows Open System Architecture (WOSA) model, Winsock defines a standard service provider interface (SPI) between the application programming interface (API), with its functions exported from Ws2.dll, and the protocol stacks. Consequently, Windows Sockets 2.2 support is not limited to TCP/IP protocol stacks as is the case for Windows Sockets 1.1.
Microsoft® Windows® CE operating system (OS) provides two built-in service providers, WSPM and NSPM, which are located in wspm.dll and nspm.dll respectively. WSPM is the default base TCP/UDP transport service provider, while NSPM is the default Domain Name Service (DNS) namespace provider. Together these two providers offer most of the functionality available through Winsock 1.1 as well as many of the features new to Winsock 2.2 like scatter/gather and overlapped I/O. However, WSPM does not support all possible functionality including multipoint and connect-time data transfer. Windows CE .Net also provides a third service provider, located in ssllsp.dll. This service provider will be built-in if SSL is included in your platform configuration. You can also create your own service providers that support the missing functionality or any additional desired functionality. Preferably such service providers should also be documented so that other application developers can make use of the extended abilities.
See Also
Last updated on Saturday, April 10, 2004
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