You generally can't set anything. It would need to match the ISP network. These values are generally set by the router when the dsl connection is established.
They are pretty worthless setting first because you have no ability to map your data into atm cells directly so you could favor some over the other and it is only used on the last mile connection. Everything past it is uses some other transport technology rather than ATM.
In addition even if you could figure something out this is only upload traffic most people have issues with their download.
You will need a much more advanced router that can limit traffic at the packet/session level. Even then it really is a bandaid for a overloaded internet connection. It does not...