The rush to wire up the US with high-speed Internet access is running into a serious problem: Too many heavy Internet users are crowding online at once, in some cases creating major bottlenecks and slowdowns.
The overcrowding problem has crept up on US cable companies as they feverishly upgrade networks and sign up customers for "broadband" services, including Internet access, cable television and phone service delivered at high speed over a single line. But in some places, these high-speed services can be anything but speedy, as households hog bandwidth.
These users aren't garden-variety heavy Web users, downloading mountains of data. They are typically customers who send torrents of data out over the Web, perhaps by streaming out video or by operating a home-based Internet site. Customer agreements for broadband services usually prohibit excessive use of this nature.
Still, bandwidth hogs are rampant in the cable-modem world, and they are one reason cable companies are pouring more money into upgrading infrastructure. The upgrades are necessary for the industry to keep pace with Bell telephone companies, wireless providers and satellite-based technology in building the high-speed Internet pipeline of the future.
Here come the 'nodes'
Most cable operators have quietly begun adding "nodes," the small, inconspicuous cabinets stuffed with electronic components positioned in neighborhoods on telephone poles or the ground. Coaxial cables connect each node directly to homes. At one time, 10,000 homes per node was the norm and, in some regions, as many as 20,000 per node was considered adequate.
Now most cable-system operators are busting down node sizes so that each one serves 500 homes or fewer. Some, such as
The cost of the nodes is nominal. What really gets expensive is the labor: Field crews install them, painstakingly transferring lines from one node to another by hand. In some cases, cable companies use the same node, but just add extra electronics and optics to each line. The whole process takes about half a day, and costs around US$5,000, estimates Alex Best, senior vice president of engineering for Cox Communications Inc., the Atlanta cable company and a pioneer in the upgrade business.
Collectively, America's cable providers say their systems comprise about one million miles of lines, passing about 99 million homes. Only about half of those households are served by systems that have been upgraded for high-speed services.
Cox's Best notes that a new type of cable modem also can manage the speed and volume of transmissions. These modems work off directions supplied by the "cable head-end," the place where network signals originate. These modems are just now beginning to be deployed, and should take care of the problem of bandwidth hogs over time, he predicts.
Bandwidth abusers
In the meantime, cable companies are left to crack down on bandwidth abusers. Although many big cable operators have the ability to monitor network traffic, small and mid-sized systems often can't keep close tabs, according to cable operators.
In New York City, a cable market served by Time Warner Inc., just 6 percent of Time Warner's high-speed customers currently account for 50 percent of usage, says Trey Smith, chief technical officer for Road Runner, the high-speed service controlled by Time Warner and MediaOne Group. In other places around the country, the effect is more pronounced, with as little as 4 percent to 5 percent of customers accounting for 85 percent of usage.
Road Runner has one of the more sophisticated traffic tracking systems in the country. Smith says the system can track virtually every byte transmitted by cable-modem customers in New York down to the node level. Figuring out which household is the source, however, is still largely a manual process.
Some cable operators have equipment in place that lets them conduct the procedure electronically. They can "scan" cable modems and personal computers to determine how much bandwidth is being sucked down.
Another option is for a field crew to make a visit to the affected neighborhood, open up the node and literally unplug lines one at a time to see if the slowdown goes away. Because this kind of manual sleuthing is time-consuming and disruptive to other customers, it is generally considered a last resort.
The architecture of cable-TV systems can make slowdowns hard to avoid. Cable-modem users log onto what is essentially the same fat pipe, sort of like a giant local area network. If too many people try to transmit information at the same time, lines can get clogged unless they are properly managed.
"The cable modem is the Internet equivalent of the old party line," says Bill Smith, chief technical officer of BellSouth, one of the Baby Bells whose own high-speed service is a rival to cable. "With so many people sharing the same bandwidth, if the network's not managed well, you're going to have problems."
Back when cable-TV companies supplied only cable TV, sophisticated network monitoring wasn't necessary. Customers couldn't really slow the system down because they were only receiving the signal, not sending it back. "In the old days, our customers were our monitors," Cox's Best notes. "A channel would flicker, and our phones lit up."
Network management is a lot trickier in a high-speed environment. Tele-Communications Inc., the cable giant that AT&T acquired last year, ran into bad traffic problems when it first rolled out high-speed services in Fremont, Calif., in late 1998. TCI discovered that some customers were using the high-speed cable connections to support whole Internet sites, slowing down service across entire sections of the system.
Problems with Excite @Home
Attempts to fix the problem only made things worse. @Home, the Redwood City, Calif., high-speed service provider now called
The result: "Everybody's service came grinding to a halt," says Tom Wolzien, a cable analyst with Sanford C. Bernstein.
Last year, Excite @Home got zapped again, this time by a series of network meltdowns, and repeated attempts to fix the problems didn't work. A number of cable operators and customers complained that Excite At Home had fallen down on its high-speed promises.
Milo Medin, @Home's chief technology officer, says the company's Internet backbone wasn't adequate for handling traffic during peak usage periods, and says a combination of issues contributed to the service headaches. Cable-system operators, whose role in delivering high-speed service includes installation, also contributed.
Medin admits that some of @Home's actions didn't help. Anticipating capacity needs is a basic part of properly managing a network. On that point, he says, At Home simply didn't deliver. "In a lot of cases, we did that pretty well," says Medin. "In other cases, we exhausted our options and we got hosed, and that caused some of our customers to get hosed."
Medin says most of @Home's network headaches have since been cleaned up. AT&T, a big investor in @Home, recently installed all kinds of new gear, including a fat, higher-capacity backbone, to ensure last year's problems won't repeat themselves.
But it's ultimately up to Excite At Home to keep things humming. "That's our job," Medin says flatly. "If we fall down on that, it's our problem."
