Chances are that by now, you have seen or heard advertisements from Internet service providers (ISPs) discussing upload and download speeds. These commercials toss numbers around like “20MB up and 20MB down," and you might assume that this guarantees that data will come into your computer from the Internet at 20MB (download) and will be sent to the Internet from your computer at a speed of 20MB (upload). 

Unfortunately, you may be sorely mistaken.