|I am being practical. |
The only other choice you have is to buy a router that does bandwidth limiting. If your brother isn't likely to stop hogging bandwidth when you want to go online just because you ask him to, he isn't likely to appreciate you limiting his bandwidth and I suspect you'll get you'd get your butt kicked by him as soon as he found out........and I'd wager he is older and tougher than you or you'd have just told him to knock off the bandwidth hogging when you wanted to go online and that would have been the end of it.
So, since you're the younger brother, buying a device capable of limiting bandwidth is just about your only option....that or telling on him. You know he's downloading illegal music, movies or software. Maybe you'll get him grounded off the computer for a while if you tell your parents. Regardless, I can't think of a single option you have that won't get you beat up by your brother so there you go.