I have a problem that requires me to calculate the maximum upload and download available, then limit my program's usage to a percentage of it. However, I can't think of a good way to find the maximums.

At the moment, the only solution I can come up with is transfering a few megabytes between the client and server, then measuring how ling the transfer took. This solution is very undesirable, however, because with 100,000 clients it could potentially result in too much of an increase to our server's bandwidth usage (which is already too high).

Does anyone have any solutions to this problem?