Hi
Hope this link will be of some help
http://www.cisco.com/en/US/products/sw/iosswrel/ps1835/products_configuration_guide_chapter09186a00800c75ce.html
You can use to limit the traffic and if it exceeds the configured value u can either drop or remark the traffic.
Very much useful in tackling the downloads from unwanted P2P sites.
1)It uses Token bucket system for limiting the traffic
2)Its used as a Policer and also for marking once the configured paramaters are met.
3)You can have either single token systm or double token system
4)You have the liberty of Choosing the traffic to Confirm and transmit,exceed and transmit or drop,Violtate action transmi or drop.
Once it starts exceeding/violating the listed parameters u can mark those exceeded or voilated traffic with different cos,ip prec values.
if u wanna know more about the same do drop out a search and that will yield u a lot to understand them properly.
regds
