Network neutrality advocates and the industry-funded lobby groups that oppose it in Washington rarely agree on issues, especially when those issues involve network filtering or throttling. That's what makes last week's letter from Hands off the Internet (a telco-backed group opposed to government network neutrality regulations) such a surprise. The group told FCC Chairman Kevin Martin that it supported an FCC investigation into Comcast's alleged BitTorrent blocking.

As increased evidence of Comcast's traffic-shaping measures came to light over the last few weeks, a handful of consumer groups complained to the FCC on November 1. The groups argued that Comcast was violating the four principles found in the FCC's 2005 Internet Policy Statement (PDF). The groups then raised the stakes by calling for a $195,000 Comcast fine for every consumer affected by the problem.

Several of the signatories to that letter are also members of pro-network neutrality group SaveTheInternet.com, and they saw the incident as a perfect counterweight to claims that neutrality isn't necessary because no company has ever violated it. It's also exactly the sort of complaint that one might expect Hands off the Internet to oppose.

Instead, HOTI's letter reiterated the FCC's four principles and called them "the necessary safety net to protect consumers and the openness and freedom of the Internet." The letter went on to say that "the ball is in your court" and that the FCC has a duty to launch an investigation of Comcast in order to see if the company has violated the principles.

What's going on here? Harold Feld, the senior vice president of the Media Access Project, believes that Comcast's tribulations are a goldmine for the telcos, who want to press their advantage. The entire BitTorrent blocking ("delaying" in Comcast-speak) debacle just shows up a basic weakness of cable's current network architecture: bandwidth is shared by all users on a local node.

"Particularly with applications tolerant of minor delays (like downloading static web pages), it was easy for cable operators to share capacity among their subscribers while claiming a very fast always on speed based on the average user load for the system," says Feld, but notes that the system doesn't work well when users start saturating their links by using high-bandwidth applications.

Because P2P apps in particular can lead to consumer complaints from other subscribers on the local node, Comcast has taken to resetting certain types of traffic to keep the load lighter. In Feld's view, this just shows up problem's with cable's network that the DSL and fiber providers (AT&T, Verizon, etc.) are keen to drive home by keeping this issue in the public eye.

Instead of spending tons of cash to upgrade its hybrid fiber-coax (HFC) network to fiber, Comcast cheaped out and instead bought some Sandvine gear to disrupt certain traffic instead.

"Looked at this way, you can see why the telcos (and therefore their sock-puppet HOTI) would be a shade peeved about Comcast's decision to 'manage' their network in such a 'cost effective' but deceptive manner," writes Feld. "Because if Comcast can keep pretending its network is just as good as FIOS when it isn't, and can even lie when asked about it directly by customers, then Verizon just wasted a couple of bazillion dollars and took a two-year stock beating for NOTHING."

With support both from the telcos and consumer groups, the FCC will certainly have to examine the issue. Its four principles haven't yet faced a good test case, and disrupting subscriber traffic in order to keep overall bandwidth down seems like a good one to start with. If Comcast's actions don't end up violating the FCC's four principles, then those four principles seem to mean little. But the FCC probably has little appetite for slapping huge fines on a company like Comcast, either.

Still, even opening up an investigation would be a win for consumers because it would show that the FCC considers itself to have the authority to act on such issues (and an interest in doing so). That alone should keep other ISPs treading cautiously, even without any new legislation. It could also be a win for the telcos, which would far prefer FCC oversight to Congressional laws.