In-path WAN optimization topology
FortiGate units can be deployed as typical security devices that protect private networks connected to the WAN and also perform WAN optimization. The WAN optimization configuration intercepts traffic to be optimized as it passes through the FortiGate unit and uses a WAN optimization tunnel with another FortiGate unit to optimize the traffic that crosses the WAN.
You can add web caching to any WAN optimization topology when users on a private network communicate with web servers located across the WAN on another private network.