Internet Content Adaptation Protocol (ICAP) profiles can be added to explicit web proxy security policies. ICAP is a light-weight response/request protocol that allows the FortiGate unit to offload explicit web proxy traffic to external servers for different kinds of processing. ICAP is often used for offloading virus scanning and web filtering but has many other applications.

If you enable ICAP in a web proxy security policy, HTTP traffic intercepted by the explicit web proxy is transferred to an ICAP server in the ICAP profile added to the policy. Responses from the ICAP server are returned to the FortiGate unit which forwards them to their destination.

You can offload HTTP responses or HTTP requests (or both) to the same or different ICAP servers. You can also enable streaming media bypass.