This is my whole point for wanting to limit upstream bandwidth!

On any network connection downloading requires some upstream bandwidth for ACK's. If the person uploading from me is taking *all* my bandwidth, there will be nothing left for this. The problem well understood - LimeWire, BearShare, and Gnotella allow you to specifically cap upload bandwidth to prevent this (Although Gnotella's method isn't great).

Gnucleus bandwidth limits work fine, it's just that it doesn't seem to have the limit I need. It will cap the total bandwidth by lowering the upload until up + down <= cap (as least this is what seems to happen), but as far as I can't see you can limit the upload bandwidth alone.

With my ADSL I have a bit over 150k down and 30k up. To preserve my download speed I only need to reserve a small bit of that upload bandwidth for myself, but if I place the total cap to 30k the upload bandwidth allowed will shrink to zero (since downloads often exceed 30k). This completely shuts people download from me out which is not what I want to do.