Limit bandwidth of Internet Sharing

[saha-med]

Hi,

I own a mac mini connected to a modem via ethernet. The mac mini shares its internet to an ipad and laptop via wifi?

Is there any way to limit the bandwidth of the wifi network, as i do now want the IPAD and laptop to compete with my mac mini for bandwidth to the internet?

Ive tried to following IPFW rules but it doesnt work

sudo ipfw pipe 1 config bw 8KByte/s
sudo ipfw add pipe 1 ip from any to any via en1

en1 is identified as the airport on my mac mini.

Please help, thanks in advance