According to an article that appeared in the Washington Post last week, Comcast has begun to disconnect subscribers whom the cable provider says consume too much bandwidth.

Comcast says that users don't receive warnings until they've downloaded the equivalent of 1,000 songs per day or four full-length movies. Users are issued a warning and are given a month to reduce their consumption. But some subscribers are crying foul, saying that the cable giant offers "unlimited" service.

Comcast refuses to divulge the exact bandwidth limit on subscribers, the amount of usage the red-carded subscribers were consuming, or even provide a way for subscribers to meter their own usage. The reason, according to Comcast, is that if they told users what their limits were, Comcast would run the risk of having all subscribers use their full limit, which would reduce the network's response significantly.

If a network is both well designed and well provisioned, bandwidth caps on individual users should never be needed, unless the subscriber's usage is governed by a service level agreement. Comcast does not provide residential users with service level agreements, so users who purchase Comcast's unlimited service have the right to expect just that: service without limits.

The "over-consumption" of bandwidth by some subscribers should not be an issue. For every over-user on Comcast's network, there is a subscriber who under-uses his or her connection. Among all users, the consumption of bandwidth should average out.

Further, it's well within the technical capabilities of network distribution equipment on a well-designed network to cap individual consumers' maximum bandwidth. If a single user is creating a problem, the single user's drop can be capped, forcing it to conform to the service limits. Comcast has obviously invested itself to the point of being able to meter individual use, so it should also be able to restrict individual use without resorting to service cancellations.

Aside from imposing a hard cap on bandwidth consumption, Comcast could "shun" over-users for a period of time - that is, deliberately slow down their service to limit their impact on the rest of the network. Comcast could also restrict heavy downloading to off-peak hours for users. The overnight period from about 1:00 AM to 6:00 AM sees relatively light use, compared to the late afternoon and evening hours. Daytime usage is typically lower than afternoon usage as well.

There's nothing wrong with placing limits on the service, as long as both parties are aware of the limits from the outset, and have the proper tools to meter and control bandwidth usage. Comcast shouldn't be secretive about the limits on the services it provides, especially when it offers hundreds of cable television channels, premium television channels, movies on-demand, digital radio, Internet and phone services all over a shared network. When Comcast cuts off these super-users, they announce to the world that they're unprepared to deliver the full range of services they're asking their subscribers to buy.