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To many proponents of net neutrality, the easy way out of this dilemma is for ISPs to increase the capacity of their networks. But they have little business incentive to do so. “Why should I put an enhancement into my platform if somebody else is going to make the money?” says David Clark, a senior research scientist at MIT’s Computer Science and Artificial Intelligence Laboratory, who from 1981 to 1989 was the Internet’s chief protocol architect. “Vuze is selling HD television with almost no capital expenses whatsoever,” Clark says. Should an ISP spend millions–or billions–on hardware upgrades “so that Vuze can get into the business of delivering television over my infrastructure with no capital costs whatsoever, and I don’t get any revenues from this?” For ISPs that also offer television service, the situation is worse. If an increase in network capacity helps services like Vuze gain market share, the ISP’s massive capital outlay could actually reduce its revenues. “If video is no longer a product [the ISP] can mark up because it’s being delivered over packets,” Clark says, “he has no business model.”

As Clark pointed out at the Harvard FCC hearing, ISPs do have the option of defraying capital expenses by charging heavy users more than they charge light users. But so far, most of them have resisted that approach. “What they have been reluctant to do is charge per byte,” says Odlyzko, “or else have caps on usage–only so many gigabytes, beyond which you’re hit with a punitive tariff.” The industry “is strangely attached to this one-size-fits-all model,” says Timothy Wu, a Columbia Law School professor who’s generally credited with coining the term “network neutrality.” “They’ve got people used to an all-you-can-eat pricing program,” Wu says, “and it’s hard to change pricing plans.”

Absent a change in pricing structures, however, ISPs that want to both manage congestion and keep regulators happy are in a bind. Can technology help get them out of it?

The Last Bit
To BT’s Bob Briscoe, talk of ISPs’ unfair congestion-management techniques is misleading, because congestion management on the Internet was never fair. Telling computers to halve their data rates in the face of congestion, as the TCP protocol does, is fair only if all those computers are contributing equally to the congestion. But in today’s Internet, some applications gobble up bandwidth more aggressively than others. If my application is using four times as much bandwidth as yours, and we both halve our transmission rates, I’m still using twice as much bandwidth as you were initially. Moreover, if my gluttony is what caused the congestion in the first place, you’re being penalized for my greed. “Ideally, we would want to allow everyone the freedom to use exactly what they wanted,” Briscoe says. “The problem is that congestion represents the limit on other people’s freedom that my freedom causes.”

Briscoe has proposed a scheme in which greedy applications can, for the most part, suck up as much bandwidth as they want, while light Internet users will see their download speeds increase–even when the network is congested. The trick is simply to allot every Internet subscriber a monthly quota of high-priority data packets that get a disproportionately large slice of bandwidth during periods of congestion. Once people exhaust their quotas, they can keep using the Internet; they’ll just be at the mercy of traffic conditions.

So users will want to conserve high-priority packets. “A browser can tell how big a download is before it starts,” Briscoe says, and by default, the browser would be set to use the high-priority packets only for small files. For tech-savvy users who wanted to prioritize some large file on a single occasion, however, “some little control panel might allow them to go in, just like you can go in and change the parameters of your network stack if you really want to.”

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