Peering is essentially an arrangement between two bandwidth providers where they send and receive traffic from each other for free. The logic is that the data sent from one network to another is reciprocated. Verizon runs one of the largest last mile networks and owns the descendants of MCI. Cogent is one of the largest bandwidth providers, and its network is spread across the globe in hundreds of cities.

Cogent and Verizon peer to each other at about ten locations and they exchange traffic through several ports. These ports typically send and receive data at speeds of around 10 gigabit per second. When the ports start to fill up (usually at 50 percent of their capacity), the internet companies add more ports. In this case, through, Verizon is allowing the ports that connect to Cogent to get crammed. ”They are allowing the peer connections to degrade,” said Dave Schaffer, chief executive officer of Cogent said in an interview. “Today some of the ports are at 100 percent capacity.”

“Think of it as the on-ramp to the freeway being log-jammed,” Shaffer said. And that means your Netflix content, especially content sent by Netflix’s content delivery network, slows down, and you get pixelated pictures and buffering.

While not naming Netflix directly, Verizon has indicated to Cogent that the reason behind its actions is that Cogent is moving traffic for a large video provider. Schaffer confirmed the Netflix is one of their largest customers. “Over the past year Netflix has become a big partner for us. This is a business model problem, not an engineering problem,” Schaffer said.

Our sources tell us that Netflix recently bought 2 Terabits of bandwidth capacity in part to get around such cramming that was happening in places where it sends traffic directly to certain internet service providers.

When we called Verizon about this story asking if Verizon was having a problem with Cogent over peering issues associated with Netflix, Verizon spokesman Bill Kula said he’d get back to us. A few minutes later he sent the following reply that didn’t answer our question:

"Verizon operates one of America’s lowest-latency, highest capacity networks. The various classes of Internet speeds we offer are among the fastest in the nation. Time and again, customers rate us best in class in various reports and surveys. Our customers enjoy a consistently superior Internet experience because our networks can adapt and grow with their use."

Netflix has been growing like crazy and it now accounts for a whole lot of Internet traffic — almost one out of every 3 bits (32.3 percent) sent downstream to users in North America is Netflix traffic according to Sandvine, a company that makes traffic monitoring gear for ISPs. That’s a lot of congested ports.

Netflix’s growing popularity has made it a target of ISP (internet service providers) vitriol and anger, especially those who offer competitive services. Verizon, for instance owns 50 percent of Redbox, a video-over-the-Internet service that is competitive with Netflix. Time Warner Cable and Comcast are other large providers that has allowed degradation of the online video experience on its networks — after all the logic is that as people start to have a bad Netflix experience, they start to look for alternatives — perhaps the ISP’s own pay TV offering.

This isn’t the first application last mile network operators have tried to degrade — last year the wrath of the Baby Bells and cable companies fell on Megaupload, a file sharing company started by Kim Dotcom, Schaffer said. That too was one of the big bandwidth-hungry services popular with the end customers of the ISPs — actual consumers.