|You have several solutions to limit bandwidth and restrict downloading:|
1. If your router supports qos, you can enable qos and limit bandwidth directly in your router.
2. If your switch supports "port mirroring" feature, you can setup a mirroring port and do filtering on this mirroring port. Monitoring programs like "WFilter Enterprise", "websense" can enable you to monitor and filter internet activities of all network computers.
3. Setup a bridge or gateway untangle box to filter internet downloading and limit bandwidth.
4. Setup a squid proxy server. squid proxy server also is very powful to filter web usage.