A dispute between two large Internet backbone providers created a massive disruption on October 6th after Level 3 Communications Inc. stopped accepting Internet traffic from Cogent Communications Group Inc. The result was that many users were unable to reach large portions of the Internet. E-mail traffic, Instant Messaging and Web traffic were all shut down unless the servers were connected through redundant links that were directly or indirectly connected to each one of the two rival networks.
Like other large ISPs, Level 3 and Cogent exchanged traffic through a no-cost Peering Arrangement. However, Level 3 alleged that it was handling far more traffic from Cogent than it was sending to Cogent. Cogent countered that the real motivation was that Level 3 was trying to force Cogent to raise its rates, which are generally below market.
The two quickly made nice with each other and the problem is solved, at least temporarily. However, it highlighted the power that the large backbone ISPs have and will likely prompt the Europeans to add another grievance to their concern regarding concentration of control in the US of the Internet.