Guarantee bandwith per IP. Mixed LAN with both 10 and 100Mbit links

[Tillebeck]

I ran into a problem.

I have a mixed invironment with both 10Mbit links and 100Mbit links (ports in switches, some are 10, some are 100Mbits). When need for trafik is high then the shaper is kicking in and reducing trafic. BUT it trafic is overall reduced by 50% then the 10Mbit links will end up with just 5Mbit…

Is there a way to "guarantee" 10Mbit per IP? It should work so bandwith is first taken from the "heavy" users (eg. 40Mbit) and first when they hit the 10Mbit  (as the users on 10Mbit links) then speed will be reduced for them to?

Another expolanation:
100Mbit links users try to download with 40Mbit and do so
10Mbit links users try to donwload with 40Mbit but since port is only 10Mbit they get 9½Mbit

Lets say traffic on WAN interface is only the half then I would like only the 100Mbit users to be reduced in bandwith until they hit same low speed as the users on a 10Mbit link.

Hope it makes sense.
BR. Anders