Out-of-path WAN optimization topology

In an out-of-path topology, one or both of the FortiGate units configured for WAN optimization are not directly in the main data path. Instead, the out-of-path FortiGate unit is connected to FortiGate units in the data path, and the device is configured to redirect sessions to be optimized to the out-of-path FortiGate unit. The FortiGate units in the data path use a method such as policy routing to redirect traffic to be optimized to the out-of-path FortiGate units. The out-of-path FortiGate units establish a WAN optimization tunnel between each other and optimize the redirected traffic.

One of the benefits of out-of-path WAN optimization is that out-of-path FortiGate units only perform WAN optimization and do not have to process other traffic. An in-path FortiGate unit configured for WAN optimization also has to process other non-optimized traffic on the data path.