Is your Internet service being throttled down?

When we old-timers were on the Web back in the early 1990s, our Internet needs were relatively small. We were mostly sending text e-mails or looking for text documents on "Gopher," an early search engine. A 14.4 modem connection felt as though we were traveling at light speed. It was all very exciting at the time – of course, back then we also thought Ross Perot was exciting.

But oh, how times have changed. These days, online users want to watch a YouTube video, access e-mail, send instant messages, play online games, and talk on the digital phone – all at the same time.

If you're noticing slowdowns while online, the culprit could be "bandwidth shaping." Most Internet service providers (ISPs) don't like to talk about it, but it's the most recent method to deal with the masses of people who use a lot of bandwidth during peak periods.

Think of bandwidth as water coming out of a faucet. If you run water all the time at full strength, you'll use a lot of it. Now imagine doing that in an area with a limited water supply. The water you use would affect how much everyone else gets. So one day, the water utility installs a special meter to regulate the flow of water into your home. If you use too much water while everyone else in the neighborhood is trying to take a shower, your water flow will be cut back.

It's the same idea for bandwidth shaping. If you use too much, you'll be cut back. Without going into a complicated explanation, currently it's much more of a problem for people with cable connections than digital subscriber line connections. (It has to do with how the "flow" comes into your house and the way it is carried there.)

The problem is not so much that we are crowding the "pipes" that carry Internet traffic – extra capacity was built during the dotcom boom of the late 1990s to handle that. But there are problems with the routers at each end of the pipeline. BBC technology writer Bill Thompson explains it this way: "If we take a backbone link across the Atlantic, there are billions of bits of data arriving every second and it's all got to go to different destinations. The router sits at the end of that very high speed link and decides where each small piece of data has to go. That's not a difficult computational task, but it has to make millions of decisions a second."

Router companies like Cisco have said in the past that they feel confident their products can handle the higher traffic. But even if that's true, other problems can arise: While a lot of the world's Internet traffic does travel on fiber, lots of it doesn't. And those old copper wires can only handle so much demand.

As a result, ISPs – in particular, cable companies – have quietly instituted polices to control the flow to heavy users. For instance, users of Time Warner's Road Runner Internet service received an e-mail notifying them that the company will use bandwidth shaping to deal with heavy users – so-called "bandwidth hogs."

On the surface, the decision seems to make sense. You don't want one person to ruin the Internet experience for many. But some people feel ISPs have misled them, throttling service, the way you throttle back a locomotive. In Britain, where bandwidth shaping has also been initiated, an e-petition on Prime Minister Tony Blair's website is campaigning against the reduction in bandwidth (http://petitions.pm.gov.uk/broadbandripoff/).

"The problem is, they are selling a product by speed and are not offering this speed at peak times [anywhere from 4 p.m. to 1 a.m.], which means the service you are paying for is not the service you bought or was advertised," writes Lee Sexton, a British engineer who started the petition drive. The petition has about 1,000 electronic signatures so far.

While Mr. Sexton is complaining about regular services, ISPs also offer premium services at higher prices so you can have more bandwidth. Will those who buy this kind of package open themselves up to a virtual slap on the wrist for their Net habits?

"It will depend on individual ISPs," says Mr. Thompson. "If they are smart, they will reserve high-speed bandwidth and routers for [premium] customers. Or they could just shape them at will, along with the customers who are paying for the lower-priced services. There is a way to do it properly, and there is a way to do it cheaply. And I suspect I know which way the ISPs will go."

For now, anyone using a high bandwidth connection should find out what their ISP's policies are. Most are posted on the company's website, but they often are well hidden. (I had to drill down into my ISP's site to find its policy.)

Before paying more for a premium connection, learn about the ISP's policies on "throttling." Otherwise, it will be like, well, opening a faucet and just watching the water – in this case, your money – disappear down the drain.