Bandwidth Control with WebProxy

Greetings.

How i can make the bandwidth if i have a webproxy? thats because i make this to activate the transparent proxy.

ip firewall nat add in-interface=ether1 dst-port=80 protocol=tcp action=redirect to-ports=8080 chain=dstnat
ip proxy set enabled=yes port=8080

And so, the petitions from the LAN are not forwarders for the router and the bandwidth control don’t work.

Best Regards.