Description: URL Filtering Operation

_________
2.2 Request   |         |
|---------->| Server  |
|           |         |
_________                      __|_          |_________|
|         |<--(5. Response )---|    | 3. Response  |  
|         |                    |    |<-------------| 
| Client  |---(1. Request )--->|FW  |
|_________|                    |____|<--------------|
| 4. URLF Resp ____|______
|             |           |
|------------>|URLF Server|
2.1 URLF Req   |___________|

1)  Client sends a Request containing a URL to the Server

2.1)  FW extracts the URL from the Request and sends it to 
URL Filtering Server (or Verifies the URL locally)

2.2)  FW also forwards the original Request from the Client to 
the Server

3)  Any Responses from the Server received before receiving
a response from URLF Server are cached by the FW

4)  URLF Response indicates whether the URL access should be 
allowed or denied

5)  If the URLF Response allows the URL, FW forwards the
URL Access responses from the Server to the Client

6)  If the URLF Response indicates that the URL access should be
denied, FW drops all the cached URL responses and forces the
connection between the Client and the Server to be terminated

Specifically, the object cufwUrlfFunctionEnabled 
indicates if the URL filtering function
is enabled.

When this MIB object contains the value 'false',
the firewall device will not perform URL filtering
function, even if it contains configuration pertaining
to other aspects of URL filtering.