Microsoft Internet Security and Acceleration Server 2000


A data-filter object may implement the IFWXSlowDataFilter interface to prevent premature termination of a connection.

When a Firewall client application calls the Windows Sockets WSACleanup function, the client DLL will close the Firewall service session. As a result, the Firewall service will terminate all connections that were created in this session.

In rare circumstances, this termination may lead to data loss if the client application relies on TCP/IP for receipt acknowledgement. The connection can be closed after acknowledgment of a packet receipt because the slow connection delays receipt of the remaining packets. This is not a problem if the client application uses application-level acknowledgement.

To prevent data loss in these cases, implement the IFWXSlowDataFilter interface.