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WinProxy's firewall is one of the new generation of 'hybrid' firewalls. These firewalls are a synergistic
combination of packet-level and application-level firewalls.
The packet-level firewall inspects the headers of every packet. Decisions to allow or disallow the packet
are based upon source and destination addresses as well as source and destination ports. This inspection
has little to do with packet content or subsidiary headers like URLs. "Stateful" packet filters, like
WinProxy allow the firewall to correlate new packets with previous traffic as part of the decision process.
WinProxy's packet-level firewall lives 'close to the wire', between the network card and the tcp/ip stack.
This firewall makes its decisions before the packets even reach the tcp/ip stack, and well before any
applications might see them.
The application-level firewall regulates the tcp/ip stack from above rather than from below. It cannot
change how your system handles individual packets, but it is well-suited to making session decisions.
Communication sessions can be limited by any number of rules, all of them available to the
administrator. These can include decisions based upon the content of the packets.
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