Modern internet routers contain so much buffering of packets they defeat TCP’s congestion algorithms. The end result is high latency on your broadband connection.
If your home router runs linux, you can mitigate this latency using QOS (i.e., traffic shaping).
My home broadband connection is rated at 12Mbps down, 1Mbps up. Using the CBQ script from the Linux QOS howto (linked above), I set the upload speed parameter to 3/4 of my available bandwidth, and the download speed parameter to 13/16. Suddenly I could surf the web while bittorrenting! This was impossible before.