I'm sure the question has been asked before, but I can't seem to find it for myself; my Google-fu eludes me.
My router, the Linksys E2000, does a decent job at being reasonable about prioritizing some sorts of traffic above BitTorrent traffic (there isn't too much interruption to port 80, 443, or 22 traffic, the ones I use most often). But other ports get pummeled. For instance, 3000 (which I use for local Rails testing) becomes almost entirely non-functioning. Xbox Live traffic (not sure about the ports, but they are in the >1000 range) doesn't do well either.
So I'm wondering how to ensure that XBL and local Rails testing maintain strong service while BitTorrent is going. Is it enough that I turn up the QoS on their associated ports to high? It doesn't seem to be as effective as when BitTorrent isn't running at all (I don't know if there's a way to deprioritize BitTorrent traffic).