global upload limit per connection

Hi what is a simple and effective way of limiting the maximum tx speed of any connection passing through my router.

Ok let me try and rephrase this. I have in place different mangle rules and pcq queue trees for bandwidth management and QoS. In addition to this I would like, for some source networks, to not allow more than 500k of TX per connection. This is an mangle rule and an addition queue tree on the particular network, correct?