Wireline Speeds Don't Always Match Promises

"Before we hear too much about how cell, WiMax, and Wi-Fi networks aren't as fast as promised, let's cast a steely eye on wired services: Whether fiber, coax, or phone lines are involved, the New York Times reports on how variables service can be at higher data rates. Wireless, of course, has more difficulties because wireline service tends to be consistent, with congestion being a secondary problem after basic line conditions. If the line is good, it's typically good for as long as the wire or glass is intact. The route out to the Internet at the ISP then becomes the next important factor, and we already know service provider dramatically oversell the ratio between downstream bandwidth to customers and their downstream feed from the Internet -- ratios can vary from 20 to 100 to 1 oversell."