Level 3 has accused Comcast of demanding fees to transfer data from Level 3's backbone to Comcast customers. Level 3 describes this as "Internet online movies and other content," which would mean everything, even though it's calling out movies. Level 3 signed a deal on November 11th to act as one of Netflix's primary network providers. In October, Internet monitoring service Sandvine said Netflix streaming represents 20 percent of all U.S. Internet non-mobile bandwidth use during prime-time hours.

Far be it from me to defend Comcast's policies, even while I am generally happy with its service. I subscribe to Comcast cable broadband service at home and at work, and it performs quite well in my parts of Seattle. I don't have much choice–Qwest has limited availability of an "up to 20 Mbps" service–so I'm lucky cable performs. And Comcast caps my 15 to 25 Mbps downstream service to 250 GB per month, with no-appeal threats of cutoff after two broken caps in a year.

Nonetheless, this may not be quite what it seems. The Internet is a syndicate of different networks that agree to interconnect on various terms. There are quasi-public meet-me network rooms in which providers all pay to connect in and traffic passes among all those present. Networks can also choose to create peering points between each other when traffic demands it.

My understanding of fee-free peering, however, is that the data transferred must be roughly equivalent, whether in a private peering arrangement or one conducted in meet-me rooms. If the traffic becomes highly asymmetric, the party doing the heavy lifting may complain, because it's bearing the cost of carrying another network's traffic, even though that may be what its users are demanding. It's possible that Level 3 is feeding such an enormous amount of data to Comcast in return for receiving relatively little that Comcast wants to leverage this into Level 3 paying for access to its network.

If that turns out to be the complaint, it's problematic. Network neutrality argues for treating all network traffic from any source the same: no throttling, no filtering, no blocking. Exceptions may be made when a network's performance degrades because of incoming traffic, but that's an infrastructure issue rather than precisely a political one.

Comcast might be taking the tack of complaining about an unequal peering relationship that Level 3's customers should be paying for without highlighting differentiated traffic. That's harder to defend against, because that would require the FCC stating that network and Internet providers cannot establish peering relationships on terms that they choose. In effect, Comcast could filter without basing it on packets.

Comcast hasn't responded at this writing, and I'm curious to see its explanation and the FCC's response. Update: Comcast told the Washington Post: "This has nothing to do with Level 3's desire to distribute different types of network traffic. Comcast has long established and mutually acceptable commercial arrangements with Level 3's Content Delivery Network (CDN) competitors in delivering the same types of traffic to our customers." Not particularly clear, but "mutually acceptable commercial arrangements" would seem to indicate peering contracts.

Update 2: Commenters indicate that a bit of clarification is needed here. I didn't properly distinguish between Comcast's handling of packets that originate from Level 3 and then pass over any path to reach Comcast, and Comcast's direct interchange with Level 3 (which some commenters argue is not properly called a peering point, although I disagree). Comcast cannot be denied to have the business basis to determine with which firms it directly contracts and to which it opens specific point-to-point pipelines for network interchange. That may be the issue at hand. Where network neutrality intrudes is if Comcast is threatening to degrade or block all Level 3 traffic on any Internet route to Comcast. While no laws or regulation specifically prohibit that, that's a different kettle of fish than wanting to collect fees for a direct network connection with Level 3.