About Application Filters
Application filters are extensions of the Microsoft Firewall service. These filters register for and process Firewall service events. By exposing COM interfaces to developers, Internet Security and Acceleration (ISA) Server allows you to extend its security and functionality. You can use these interfaces to extend the security and access control for the Firewall service, and to create protocol-specific application filters. These filters can share the architecture, access control, and administration of the Firewall service.
This section contains the following topics: