managing internet bandwidth for LAN users through Linux Gateway Box

Hi,

I wish to control and manage internet bandwidth to users and workgroups working through my server, on my local LAN.

On my server I am having CentOS 5.0 Server g a Internet through satellite to my server within the current week.

Now I wish to limit 10Kbps download speed to be set for all LAN users (workgroup), not to get more than a fixed size of internet bandwidth.

So please help me regarding this.

Thanks in advance.