When you connect on PPP for broadband your router gets a reply message. Some routers allow you to see this, e.g. a FireBrick. Until now this has simply been a circuit ID, e.g. BBEU and a number. We are changing this to include the speed information (down/up) after the circuit. The plan is for FireBricks to be able to pick up the uplink speed and adjust rates for bonded uplink automatically. E.g. BBEU39074416 16789000/1171000 for an ADSL line that is synced at 16.789M down and 1.171M up.
FireBrick alpha build 1.55.113 Hamman+ Alpha has the code with means to use this change to control uplink speed. A new auto-percent setting sets tx speed to a percentage of that reported as the uplink sync - you need to allow for ATM overheads, so setting below 100% is normal.