A feature of Microsoft Proxy Server version 2 that enables Proxy Server to do the following:
Dynamic packet filtering involves two Proxy Server components:
In a typical scenario, a client with the Winsock Proxy client might attempt to connect to an Internet server using Telnet. The Winsock Proxy client intercepts the Telnet connection request and remotes the request to the Winsock Proxy server, which verifies that the client has proper Microsoft Windows NT permissions to use Telnet to access servers on the Internet and opens a local socket.
The Winsock Proxy server then informs the Packet Filter Manager that an outbound connection request from the socket to a remote Telnet service has been approved, and the Packet Filter Manager orders the Packet Filter Driver to open the socket and the Winsock Proxy server to start a Telnet session on behalf of the client.
When the Winsock Proxy determines that the client has closed the Telnet session, it tells the Packet Filter Manager to close the socket and thus blocks any further packets from the remote system.