We were recently the first to report that the FCC was concerned that Comcast's new de-prioritization system would degrade competing VoIP traffic, the agency writing a letter asking Comcast to explain how this wasn't anti-competitive, and why they hadn't previously mentioned the system's impact on VoIP. The new, protocol agnostic system was deployed late last year, after our users discovered Comcast was forging TCP packets in order to slow P2P traffic for all users -- a practice that resulted in an FCC investigation, and a rather toothless "sanction."

Comcast's new system temporarily de-prioritizes the traffic for customers who meet two criteria: they're on a congested node, and they have been using 70% or more of their assigned upstream or downstream throughput for more than fifteen minutes. The FCC only just realized that these restrictions will impact competing VoIP services, but not Comcast's own Digital Voice service. The FCC's late discovery speaks to the often glacial movement speed of the agency.

In addition to arguing the system was an anti-competitive weapon against other VoIP, the FCC argued that because Comcast's Digital Voice service rides on a different layer from their broadband service and is not impacted by congestion management, it's technically a telecommunications service -- and subject to regulation and assorted fees. The FCC some time ago ruled cable and telco broadband were "information services," thereby freeing them from significant regulation.

This week Comcast filed their response (pdf) with the FCC, the pleasant but clinical retort denying that there was any discrepancy between their original filing with the FCC and their implemented system. Comcast insists they've always made clear their Digital Voice service is not an "over the top" VoIP solution, and thereby not part of their high speed Internet (HSI) service -- in turn not subject to the FCC's demands. Comcast tells the FCC that if it makes them feel better, they do treat all over the top and content services the same, be they from Comcast or elsewhere. Comcast insists "enormous resources" are spent on being fair:That was made evident in our recent report that Comcast was working on an online storage system the company tells us will count against the 250GB monthly Comcast cap. As for whether Comcast's treatment of competitors' VoIP is anticompetitive, the FCC will likely pursue the issue further, given former FCC boss Kevin Martin is being replaced by interim and replacement leaders who both actually believe in network neutrality. Comcast says they have worked closely with carriers like Vonage to ensure quality communications, but that may not be enough.

"We hope this letter clarifies the 'apparent discrepancy' you perceived," the letter from Comcast lawyers sweetly concludes. The ball now sits in the court of interim FCC boss Michael Copps, and soon-to-be FCC boss Julius Genochowski.