The SPI also allows you to develop two types of transport service providers—base and layered service providers. The same holds true for the WSA versions of these functions.
A side affect of these system processes loading LSPs is that such processes never exit, so when an LSP is installed or removed, a reboot is required.
The Winsock 2 SPI allows software developers to create two different types of service providers—transport and namespace. Winsock now has the ability to self-heal after a user uninstalls such an LSP. A firewall LSP should only inspect data and deny request but not actually modify the data.
LSPs and base providers are strung together to form a protocol chain. Winsock LSPs are available for a wide range of useful purposes, including internet parental controls, and web content filtering.
Base service providers implement the actual details of a transport protocol: setting up connections, transferring data, and exercising flow control and error control. A feature of LSP and Winsock proxy sniffing is that they allow traffic to be captured from a single application and also enable traffic going to localhost For example, an LSP that returns the wrong number of bytes sent through an interface can cause applications to go into an infinite loop while waiting for the network stack to indicate that data has been sent.