MSOs Find No Easy Fix For Illegal Modem Nets

The popularity of home networking among residential customers is on the rise. But that rise has also created a new problem for MSOs: The same wireless 802.11b technology that allows a subscriber to link multiple devices also can be used to illegally share a broadband connection between households.

Think of it as the Napsterization of the cable-modem connection.

While most believe the number of subscribers who are illegally trying to resell their service is relatively small, the concept does point up a major weakness — at least from a network perspective. Cable operators cannot distinguish between a legal wireless home network and an illegal network shared among households.

And some are saying the only way operators can avoid being ripped off by illegal customer link-ups is to move to a consumption-based cable-modem service, in which subscribers are charged according to the amount of bandwidth they use.


The issue recently came to the fore when Time Warner Cable's New York City division spotted ads posted on the Internet from customers in apartment buildings, offering to share their Road Runner cable modem via a WiFi wireless-networking connection. The MSO sent out a stern letter to the suspected violators, warning them to stop the practice or face disconnection or legal action.

Time Warner found these alleged resellers because they advertised their presence, but otherwise, such networks could go unnoticed. That's because many networks use Network Address Translation, which provides a single outside Internet-protocol address to all computers or devices within the home network.

To the outside cable-network management systems, these devices look like a single IP address.

"There is definitely curiosity on cable operators' parts to find out as much as they can about the CPE [customer-premise equipment] and the in-home network, but everyone agrees that Network Address Translation creates a blind spot that current technology cannot address," said Jason Schnitzer, cofounder and chief technology officer at Stargus Inc., a specialist in network-management and monitoring software.

"There will always be a way to make multiple computers look like one — not necessarily because of the limitations of cable modem technology, but the sort of mechanisms inherent in Internet protocol," he said.

Some help is on the way from Cable Television Laboratories Inc.'s fledgling CableHome specifications, which include tools to automatically configure home networks.

The CableLabs tools will each device by its unique Media Access Control address and tying each into the cable version of NAT.

Under this schematic, cleverly dubbed Cable Addressable Translator (CAT), these devices could still be identified by their MAC address.

"However, if somebody really wants to bamboozle you one way or another, then right now, at least with the technology you have, you couldn't tell," said CableLabs president Dick Green.


Time Warner isn't the only MSO concerned about WiFi-enabled theft. AT&T Broadband has a marketing deal with home-networking device maker Linksys Group Inc., which offers an 802.11b option.

But the Denver-based operator has noted some abuses. Now, the challenge is to maintain a balance between encouraging customers to fully use their broadband connection and protecting the cable plant's resources from abusers, according to spokeswoman Sarah Eder.

As a result, the MSO bases its reaction to usage-policy violations on whether the network is shared accidentally or intentionally.

Those customers who make it clear through a Web advertisement that they are illegally sharing their connection are served notice.

"When we see the sites up there we are cataloging them now, researching them, doing some wireless sniffing in some areas — seeking out these networks, and gearing up to alert these customers that we know they are violating the acceptable-use policy," she said.

Such actions may also lead to a consumption-based billing format. Conversations about that are "starting to come up," Eder said.

Indeed, Stargus' Schnitzer said the only way to solve the problem is to move to consumption-based billing, in which cable-modem service is sold the way a utility might proffer electricity or water.

"One of the reasons people don't plug an extension cord into their house and hang it over the fence to share power with their neighbor is they are aware it is going to cost them money," Schnitzer said. "You port that over to the cable-modem world, and it makes sense that the only way that we can pull this off is to monitor consumption and not content."

CableLabs's Green agreed.

"In the end, I think that just has to be an economic equation," he said. "So rather than try to address this in a technical way and say, 'We can absolutely prevent this,' what we really say is, 'We think that the best approach to this is an economic one.'"

There really isn't a technology fix that can provide evidence of illegal cable-modem networks, agreed Kinetic Strategies Inc. cable-technology analyst Michael Harris.

"Frankly, the concept of trying to cap end points behind the box is asinine and inherently unmanageable," he said. "If MSOs are really concerned about it, you can either cap bandwidth — i.e. the speed at which you download — or you can cap the amount which you download.

"I think you will see both," Harris continued. "The former is basically a marketing tactic to essentially attract more users to the service. The second is a way to penalize heavy users. And I think the challenge MSOs are going to have is, basically, defining a fair consumption number that isn't going to limit their core customer base."