As the evidence that Comcast is doing something untoward with BitTorrent and other traffic on its network has mounted, the cable company has tried clumsily to fend off accusations of wrongdoing. The latest developments come in the wake of several conference calls held by the ISP in which it attempted to make a case for its practice of sending forged TCP reset packets to interfere with some P2P traffic.

Timothy B. Lee, who is a regular contributor to the Tech Liberation Front blog as well Ars Technica, was invited to sit in on one of yesterday's conference calls, along with folks from a handful of think tanks. According to Tim, the Comcast engineer on the call said that the Lotus Notes problems were a known side effect of Comcast's traffic shaping practices, one the company was trying to fix. The engineer also "seemed to implicitly" concede that the accounts about the forged packet resets were accurate.

Delaying as a blocking tactic

The company still claims that it is isn't blocking BitTorrent and other P2P traffic, just "delaying it." In a statement given to Ars earlier today, a Comcast spokesperson denied that the company blocks traffic. "Comcast does not block access to any Web sites or online applications, including peer-to-peer activity like BitTorrent," the spokeperson told Ars. "Our customers use the Internet for downloading and uploading files, watching movies and videos, streaming music, sharing digital photos, accessing numerous peer-to-peer sites, VOIP applications like Vonage, and thousands of other applications online. We have a responsibility to provide all of our customers with a good Internet experience and we use the latest technologies to manage our network so that they can continue to enjoy these applications."

Comcast VP of operations and technical support Mitch Bowling put it this way. "We use the latest technologies to manage our network so that our customers continue to enjoy these applications. We do this because we feel it's our responsibility to provide all of our customers with a good Internet experience."

Another Comcast executive told the New York Times that the company "occasionally" delays P2P traffic, "postponing" it in some cases. His rather clumsy analogy was that of getting a busy signal when making a phone call and eventually getting through after several attempts. "It will get there eventually," is the takeaway message.

That's a distinction without any meaning. If someone is preventing my calls from going through and giving me a busy signal, the effect is the same. At the time I am trying to make the call, it's being actively blocked; calling it "delayed" is merely an exercise in semantics. Comcast is, in effect, impersonating the busy signal and preventing the phone at the other end from ringing by issuing TCP reset packets to both ends of a connection.

What's particularly troublesome is that Comcast's FAQ leaves customers with the impression that all content will flow unfettered through its network. One entry states that Comcast engages in "no discrimination based on the type of content," saying that the ISP offers "unfettered access to all the content, services, and applications" on the Internet. Another FAQ entry informs customers that Comcast does not "block access to any Web site or applications, including BitTorrent."

What did I do wrong?

Comcast's attempts to clarify its traffic shaping practices are having the opposite effect of what the company intends. As is the case with its nebulous bandwidth caps, customers can find themselves running afoul of what appears to be an arbitrary limitation imposed by the ISP. As a result, Comcast's customers don't really know that what they're paying for, aside from a fast connection that may or may not give them access to the web sites and applications they want. The company's public comments on the traffic shaping issue are intended to leave the impression that, like the bandwidth cap issue, this only affects a handful of bandwidth hogs. But judging by the comments we've seen from our readers and on other sites, there are either a lot more bandwidth hogs than Comcast leads us to believe, or the company's traffic shaping practices extend further than is being disclosed. Without some transparency from the ISP, we're left to guess.

Comcast has a handful of options to choose from. The company can own up to what it's doing and tell customers how to avoid running afoul of its BitTorrent regulations. Comcast could also continue on its current course, keeping its opaque traffic management practices in place. The cable giant's best option may be dropping the practice of sending false TCP reset packets altogether.

There are a couple of reasons that the third option may be the best choice for Comcast. First, it may be against the law. An Indiana University PhD student and Cnet contributor believes that the illicit reset packets may violate state laws in Alabama, Connecticut, and New York against impersonating another person "with intent to obtain a benefit or to injure or defraud another" (language from the New York law). In sending out the spoofed packets, Comcast is impersonating the parties at either end of the connection.

When the market can't sort things out

Legal concerns aside, Comcast is providing net neutrality advocates with plenty of ammunition. Comcast is not running a neutral network right now, and its traffic shaping choices are degrading the broadband service of many a Comcast customer.

In a perfect free market, customers would be free to pack up in leave Comcast for greener and more open broadband pastures, but the competitive landscape in the US doesn't always provide that kind of choice. More than a few Comcast customers are faced with the choice of Comcast or dial-up, leaving them with the Hobson's choice of hoping their data packets can evade Comcast's traffic shaping police or not having broadband service at all.