Qos With Rhel4

[uwa45]

Hi all, first of all let me describ my network. i have a total of 120 computers connected to the internet through a cable modem and i have a bandwidth of 128/256.
when the systems are active, my surfing speed crawls but when just one to three systems are active the speed is great.when i check my bandwidth useage, my upstream bandwidth is usually very elevated and close to the downstream.now i have suspect virus activities but after scanning no virus or worm was found. i have searched the internet for solutions and am now thinking of setting up a linux gateway with qos to shape the traffic and also to remove the upstream queue from the cable modem
i found alot of tools to use but am not sure of which to actually do the work.
am looking at wondershaper,hbt tool. but i need to know if the redhat enterprise linux 4 is compile with qos option or to i have to compile the kernel for that myself (also for fedora 3 and redhat 9) and which of the option best suits my case for doing qos?

thanks.

[elizalde]

Have you found the answer already? Have you tried using squid, "delay pool ACL"?