Comcast, the second-largest broadband provider in the U.S., has filed a court appeal of a U.S. Federal Communications Commission ruling last month saying the company couldn't delay some peer-to-peer traffic on its network.

The FCC, on Aug. 1, voted 3-2 to prohibit Comcast from slowing BitTorrent P-to-P traffic in an effort to reduce network congestion. Commissioners voting against Comcast said the traffic throttling violated FCC net neutrality principles.

Comcast on Thursday asked the U.S. Court of Appeals for the District of Columbia Circuit to review the FCC decision, saying the commission had no hard rules against the company's network management practices. The FCC's net neutrality principles, adopted in 2005, set out general guidelines, but no specific prohibitions, Comcast said.

Comcast filed the appeal to protect its legal rights and to "challenge the basis on which the commission found that Comcast violated federal policy in the absence of pre-existing legally enforceable standards or rules," David Cohen, Comcast's executive vice president, said in a statement. "We are compelled to appeal because we strongly believe that, in this particular case, the Commission's action was legally inappropriate and its findings were not justified by the record."

However, Comcast will abide by the FCC's order during the appeal, and it will continue with plans to move toward other network management techniques by the end of the year, Cohen added. "We will follow through on our long-standing commitment to transition to protocol-agnostic network congestion management practices by the end of this year," he said. "We also remain committed to bringing our customers a superior Internet experience."

Last week, Comcast announced it would put a 250-gigabyte-per-month bandwidth cap on residential customers. Customers may get a warning if they go over the monthly cap, and after their first warning, Comcast will suspend their service for a year if they go over the cap a second time.

That cap, which goes into effect Oct. 1, received mixed reactions, with some Internet users saying a cap is preferable to blocking or slowing specific applications. Some critics complained, however, that the cap could penalize certain types of subscribers, such as those who download movies frequently. The average Comcast user uses less than 3 gigabytes per month, Comcast said.

A spokesman for Public Knowledge, among the three organizations that asked the FCC to investigate the Comcast BitTorrent traffic throttling, said he was not surprised by the appeal. "We expected that they'd appeal," said Art Brodsky.

Comcast's traffic management was unveiled by press reports in late 2007. The company didn't tell its subscribers that it was slowing BitTorrent and other P-to-P traffic until the press reports. Comcast later said it was slowing P-to-P traffic only during times of network congestion, but FCC Chairman Kevin Martin and some independent tests suggested Comcast was slowing that traffic around the clock.