(FORTUNE Magazine) – Paul Deninger is chairman and CEO of Broadview Holdings, a technology investment bank and private-equity investor. He was interviewed by FORTUNE's Julie Creswell.

There has been a ton of investing activity around the buildout of high-speed backbone capability. Metro access is the key theme right now.

Think of broadband access as water. If you have a huge pipe full of cool, clear, fresh water flowing past your neighborhood but all you have coming off that pipe to your home is a quarter-inch copper tube, it doesn't matter how much water is flowing down that pipe past your neighborhood because you can't get at it. This might be called the last mile. It's an area where there is no obvious technology winner yet, but it is the gating factor to ubiquitous broadband.

DSL and cable provide some form of high-speed access to a broadband network. There are three other competing technologies: direct fiber, right to the building; fixed wireless or microwave; and a new area called free-space optics, which is lasers through the air. The next five years are going to bring a shakeout in broadband access. Clearly not all of those technologies are going to survive.

All transport-service markets eventually become commodity markets. A great analogy might be the railroads. People invested like crazy in the railroads when they were first being built out. They were laying rail track next to other rail track, creating competing railroads. But if you read the economic history of the railroads, what you'll see is that they almost all lost money, and many went bankrupt. It was only when the industry rationalized and consolidated itself--and that was only possible after the standards had been set--that a proper railway could be built out. And by the way, the guys who really won in the end were not the railroads; it was the oil companies, the people who used the infrastructure.