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managing the cost of its service by managing congestion may well
have to throttle back heavy users," says Bob Briscoe, chief researcher
at BT's Networks Research Centre in Ipswich, England. "An opera-
tor that wants to pick winners and chooses to say that this certain
application is a loser may also throttle back the same applications.
And it's very di cult to tell the di erence between the two."
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 whatso-
ever," Clark says. Should an ISP spend millions---or billions---on
hardware upgrades "so that Vuze can get into the business of deliv-
ering television over my infrastructure with no capital costs what-
soever, and I don't get any revenues from this?" For ISPs that also
o er 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 tari ."
The industry "is strangely attached to this one-size-fits-all model,"
says Timothy Wu, a Columbia Law School professor who's gener-
ally 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."
The idea that an Internet
service provider (ISP) would
make value judgments
about the packets traveling
over its network makes
many people uneasy. Once
ISPs get in the business
of discriminating between
packets, what's to prevent
them from giving their own
customers' packets priority?
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 peri-
ods of congestion. Once people exhaust their quotas, they can keep
using the Internet; they'll just be at the mercy of tra c 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."
Just granting users the possibility of setting tra c priorities
themselves, Briscoe believes, is enough to assuage concerns about
network neutrality. "I suspect that 95 percent of customers, if they
were given the choice between doing that themselves or the ISP
doing it for them, would just say, Oh, sod it, do it for me," Briscoe
says. "The important point is they were asked. And they could have
done it themselves. And I think those 5 percent that are complain-
ing are the ones that wish they were asked."
In Briscoe's scheme, users could pay more for larger quotas of
high-priority packets, but this wouldn't amount to the kind of usage
cap or "punitive tari " that Odlyzko says ISPs are wary of. Every
Internet subscriber would still get unlimited downloads. Some
would just get better service during periods of congestion.
In order to determine which packets counted against a user's
quota, of course, ISPs would need to know when the network is
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