The basic FortiGate WAN optimization topology consists of two FortiGate units operating as WAN optimization peers intercepting and optimizing traffic crossing the WAN between the private networks.

As shown in Figure 313, FortiGate units can be deployed as security devices that protect private networks connected to the WAN and also perform WAN optimization. In this configuration, the FortiGate units are configured as typical security devices for the private networks and are also configured for 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.

As shown in Figure 314, you can also deploy WAN optimization on single-purpose FortiGate units that only perform WAN optimization. In Figure 314, the WAN optimization FortiGate units are located on the WAN outside of the private networks. You can also install the WAN optimization FortiGate units behind the security devices on the private networks.

The WAN optimization configuration is the same for FortiGate units deployed as security devices and for single-purpose WAN optimization FortiGate units. The only differences would result from the different network topologies.