The tactic, which the company also confirmed Wednesday it is considering, would seem to be the latest in a series of efforts by Comcast to ease the growing strain on its network caused, in particular, by peer-to-peer file sharing and technologies such as Bittorrent.

Comcast, which has roughly 14 million subscribers, reportedly downloading an average of 2 gigabytes per month, has for several years employed a policy of calling customers who use up several times that average bandwidth and asking them to reduce their use or cancel their accounts.

The company has seen criticism from customers for not being perfectly up-front about the level of use that would elicit such a call. So the decision to officially cap bandwidth would make the process more transparent.

In recent months, Comcast has been one of the telcos deeply involved in the debate on "net neutrality," the regulatory conversation in which carriers argue they should be allowed to prioritize traffic, or to charge content sites a premium for more reliable delivery of their content.

In an issue even more directly related to Bittorrent traffic, Comcast has been criticized for being one of a relatively long list of ISPs that either block or throttle Bittorrent traffic. The company has retracted its decision to block Bittorrent traffic outright, but is well noted for working against the massive bandwidth hit the software delivers.

The traffic throttling response to Bittorrent traffic is a significant telecommunications issue that has cropped up with more frequency lately, as in the case of major carrier Bell Canada, which recently came under fire from smaller ISPs after reporting plans to "manage" Internet traffic.

There are certain obvious questions raised by Comcast's thinking about capping traffic, regarding the legal or business implications of adding a limit to a service that was previously fairly widely understood to be unlimited.

But by Comcast's description, an "excessive user" would be somebody who sent 40 million emails or downloaded 50,000 songs in a month. It seems fairly unlikely that only the most committed users could manage to download that much content consistently, considering that even at a conservative 3 minutes per song, it would take roughly three and a half months to listen to all that music.

The bandwidth cap Comcast is considering would reportedly be roughly 250 gigabytes per month, which would translate to something more like 6,000 songs, or say, 50 high definition movies - likely still more than enough for most users. Those that exceed the cap would be charged at a per-ten-gigabytes rate of $15.

The numbers and prices in the cap are not set in stone, certainly, because the company is still considering how it would apply the cap, or whether it will apply it at all.

Rival ISP Time Warner Cable is currently in the process of rolling out a test run for a graded service that would offer different amounts of bandwidth at different monthly rates. And several other US ISPs already have caps on their bandwidth use or similarly graded service offerings.