Windows Filtering Platform (WFP) is a set of API and system services that provide a platform for creating network filtering applications. The WFP API allows developers to write code that interacts with the packet processing that takes place at several layers in the networking stack of the operating system. Network data can be filtered and also modified before it reaches its destination.
By providing a simpler development platform, WFP is designed to replace previous packet filtering technologies such as Transport Driver Interface (TDI) filters, Network Driver Interface Specification (NDIS) filters, and Winsock Layered Service Providers (LSP). Starting in Windows Server 2008 and Windows Vista, the firewall hook and the filter hook drivers are not available; applications that were using these drivers should use WFP instead.