• by Wendy Davis  @wendyndavis, January 20, 2009

Net neutrality advocacy group Free Press is cheering news that the Federal Communications Commission is continuing to investigate Comcast for how it manages its broadband network.

The FCC, which has already sanctioned Comcast for impeding peer-to-peer traffic, just sent a letter to the company demanding an explanation for why it appears to favor its own digital telephone services over those of competitors.

On Monday, Free Press praised the move--saying that it, too, saw cause for concern over how Comcast handles Voice over Internet Protocol phone service. "This letter is a positive sign that the FCC's Comcast decision was not a one-and-done action on net neutrality," Ben Scott, policy director of Free Press, said in a statement. "We are pleased that the commission is conducting an ongoing investigation into network management practices that might impact users' access to the online content and services of their choice."

A Comcast spokesperson said the company is still reviewing the FCC's letter, but has "fully complied with the FCC's order regarding our congestion management."

Comcast posts on its Web site that it might occasionally slow Voice over Internet Protocol telephone service to control traffic, but will not do so for its own Digital Voice service. The FCC questioned that policy in its Jan. 18 letter to Comcast. "We ... ask that you provide a detailed justification for Comcast's disparate treatment of its own VoIP service as compared to that offered by other competitors on its network," the FCC said in the letter, addressed to Comcast vice president for regulatory affairs Kathryn Zachem.

The FCC's latest missive to Comcast comes several months after outgoing chair Kevin Martin voted with the two Democratic commissioners to sanction the company for violating net neutrality principles by impeding peer-to-peer traffic. The broadband company acknowledged that it slowed such traffic to manage congestion--but last year, while under investigation by the FCC, it promised to deploy protocol-agnostic techniques going forward.

Comcast's new system places users in two buckets--"priority best effort" or the potentially slower "best effort." Subscribers start off in "priority best effort," but can be downgraded to "best effort" if they have used a high amount of bandwidth in a 15-minute period at a time of peak traffic. When those users decrease bandwidth use for a 15-minute period, they are returned to "priority best effort" status.

Comcast says that users downgraded to "best effort" might potentially notice some choppiness in VoIP calls, but not calls placed through its own Internet telephone services.

Free Press raised questions about Comcast's new system as far back as last October. "To put it plainly, is Comcast Digital Voice being given a free pass around the congestion to which it contributes?" the group asked in an FCC filing.