Limit bandwidth on outgoing traffic

I was trying to limit the traffic for a virtual server on an LTM. In Acceleration / Bandwidth Controllers a policy was created and applied to the virtual server. No limit kicked in as we still saw more traffic going out than the configured limit. After reading this (in the tech manual) "The BIG-IP system now applies rate enforcement to the traffic intercepted by this virtual server, according to the static bandwidth policy you selected. A static bandwidth policy associated with a virtual server applies only to client-initiated flows, and not to bandwidth for traffic flowing toward the client." it became clear that this is not the solution. We would like to limit the traffic outgoing. Does someone have any suggestions ? Currently running under version 12.1.3 which we now is old and plan to upgrade.