I'm building an application that will move around some potentially large files, but I want to do it without disturbing the user's network connection by flooding it. I know that Windows BITS has this kind of functionality, and that's essentially what I'm looking to replicate (as far as the throttling goes). I know BITS has other functionality as well that I'm not interested in, and I also have the option to consume it from .NET, but I'm interested in how it works.

I've looked online, and I haven't found a clear explanation of how exactly BITS determines how much bandwidth to consume, aside from a vague "BITS polls activity to watch for a drop in the bandwidth used by other programs." What does this mean? Bandwidth consumed by other programs can drop for a number of other reasons as well - can BITS tell the difference? If I was looking for a process that replicated this "stay just under the radar, where the user won't notice the transfers" functionality, how would I go about doing it?