A special Halloween edition of the Renesys Blog: That which was whole is now torn asunder, and cries of grief ring out throughout the land. Cogent (AS174) and Sprint (AS1239) are no longer connected to each other. Customers of each network who do not have other providers—namely single-homed customers—cannot reach each other. Two large portions of the Internet are separated.
Cogent is frequently involved in peering disputes. In the last three years, the only significant peering dispute (one that caused a temporary partition of the Internet) that did not involve Cogent was between Level 3 and XO. That one was settled very quickly. All of the others (Cogent depeering Telia, Level 3 depeers Cogent, and further disputes going back years involving Teleglobe (now Tata, AS6453), France Telecom (AS5511)) involved Cogent.
But in this case, Cogent may have picked the wrong sparring partner. In the past, Cogent won peering disputes simply because their customer base was less sensitive to the outage than the other party in the dispute. Ultimately, the one whose customers complain the loudest loses. This time it may be very different. Sprint hasn't paid any particular attention to its IP product and network at a senior management level for a very long time. They are clearly focused on wireline and wireless telecom services and Overland Park management seem to remain mostly unaware that they even operate an IP network. In other words, Cogent has picked a fight with a zombie here. They may even rip off a limb or two, but that doesn't mean the zombie will notice.
Sprint and Cogent only starting peering recently, back in November of 2006. Prior to that the two networks reached each other via NTT Communications (AS2914). Now, almost exactly two years later, it appears that Sprint has disconnected Cogent and chosen to divide the Internet. Cogent has stated that they will litigate this issue so this one is unlikely to get resolved quickly. In the mean time, over 200 downstream autonomous system customers of each organization cannot reach the networks in the other. This is ugly and will remain so.
Let's take a quick look at what we know so far and set the stage for a story that will likely continue for several days, if not weeks. I'll also try to set this in a larger context about the evolution of each of these networks and the evolution of Internet interconnection on the whole.
