Bad performance with ICAP

Hi!

I am using a FG200E in transparent, proxy mode with FortiOS 5.6.7. To add some security on 0-day-malware, I want to use an external ICAP-server additional to the built-in AV (Lastline Sandbox).

The solution is basically working, but the performance is pretty bad on websites with many JS-scripts. Using ICAP slows down the overall expirience on web-surfing-speed.

If I use the same ICAP-server with squid-proxy, everything is fine.

Did you ever use ICAP with fortigates? Did you have the same problems, or is there anything, you can recommend me?

There seem to be VERY few configuration parameters for ICAP....

Thank you for your help!

KPS