Hi..I have VS on port 443 , end to end encryption. with a pool assigned.default TCP profile for client and server protocol

And irule is mapped which is basically to block restriction to certain uri . Below is the irule

when HTTP_REQUEST {
         if { [string tolower [HTTP::uri]] starts_with "/operator" } {
         drop
        }
    }

There is delay in loading of the page which consists of iframes and banners. When i remove the irule, there is no delay. 

It takes 30 seconds with irule and 2 seconds without irule. Can anyone let me know what could be done ?I tried below irule thinking it is more optimized

when HTTP_REQUEST {

set uri [string tolower [HTTP::uri]]
  if { $uri starts_with "/operator" } {
    drop
    }
    }

But it is still slow.

Do help me out.