I've tried what Bert is saying many times. Never worked for me. Not on BOps3, IW nor BOps4. I don't think it works that way but thats just from my experience.
In fact, iirc, lowering your bandwitch as much as 256k/s, you can't even connect to the CoD servers. I remember having trouble connecting when I tried lowering mine to 1mb.
Also, thats no good when you have 25+ devices connected to your router 😛 Gonna piss someone off when they try to connect and can't.
EDIT : In fact... just tried it... made no difference. I'm not even sponging, everyone still spots me as they should.