Sounds like this is also what I have been wanting but for a different reason. Now that I am using Verizon 4G as my home internet with very fast speeds, but limited monthly bandwidth, I'm wanting a test that I control the size of the download and upload file. I've actually quit testing, except for rarely, since one download and upload test will use 20M or more. That is a big chunk of my monthly 5GB. 5GB is only approx 160M per day! Will look forward to a true manul test, even though it may not as accurate as your other tests. I just need to not use a lot of bandwidth while testing. Thanks
