In response to an order from the US Federal Communications Commission in August, Comcast Corp. released on Friday a "protocol agnostic" network management plan that could result in poorer performance for the heaviest users.

On August 1, the FCC found the cable operator in violation of net neutrality rules, meaning that despite Comcast denials the agency believed the company was restricting point-to-point traffic such as BitTorrent. Among other things, the report that Comcast released on Friday conceded that the company had indeed done that, though by way of protocols and not content.

"Comcast established thresholds for the number of simultaneous unidirectional uploads that can be initiated for each of the managed protocols in any given geographic area; when the number of simultaneous sessions remains below those thresholds, uploads are not managed. The thresholds for each protocol vary," according to Attachment A: Comcast Corporation Description of Current Network Management Practices (PDF available here). "These management practices were not based on the type (video, music, data, etc.) or content of traffic being uploaded."

The new network management system has been tested in five cities for three months and will be rolled out to all Comcast cities by the end of the year -- which the company had planned to do before the FCC order, Comcast said. No customer complaints were recorded about the new method, though some users complained that the cities tested -- Colorado Springs, Colo.; Warrenton, Va.; Chambersburg, Pa.; Lake City, Fla.; and East Orange, Fla. -- weren't representative of other major Comcast cities such as New York. Fewer than one percent of users were affected on a typical day, Comcast claimed.

Here's how it works: If a network isn't congested, nothing will happen and people can use the service as they always do. However, if the network becomes congested, the heaviest users will get a lower priority for their traffic, until the congestion clears.

Comcast also created a Web page with information about the new network management method, including copies of all the relevant documentation with the FCC.

The 250 GB limit that Comcast imposed on users in August, to be made effective in October, is still in place, according to a Comcast spokesman. Previously, Comcast had limited access if users reached a certain throughput level -- the top 1/10 of 1% of users -- but had not given users a specific consumption limit.

In the meantime, users of peer-to-peer networks are trading methods for maximizing their Comcast use without hitting the various limits.

There has been concern that Comcast's action will be seen as a precedent by other major carriers such as AT&T and Time-Warner. Indeed in August, AT&T announced changes to its terms of service that limit the use of broadband Internet.