Bandwidth control on a Cisco 1721?

We recently upgraded to a Cisco 1721 as our internet access point for our
dozen client workstations and several web servers. We're running IOS
C1700-ADVSECURITYK9-M), Version 12.3(8)T1 and the Cisco SDM web management
software Version 1.2 with 128 mb of Total Memory and 32 mb of Flash Memory.

The problem is, several of our client workstations have a tenancy to 'hog'
too much bandwidth during some downloads and online gaming. We understand
there is a way control bandwidth from within the 1721, but don't know what
the protocol is named.

What would you recommend we use to allocate bandwidth to a few select client
workstations? Ideally we want to set a maximum upload rate and a maximum
download rate in the router for a couple workstations by internal IP.

Thanks!

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