Just a week ago, this might have been a stupid question; but since a couple of days, there are three internets. Or more, depending on how you look at it; but essentially there are now three worldwide networks:
- The “Internet”; a computer network that allows any computer connecting to it to communicate with any other computer.
- The “Sprint Internet”; a network that is almost as large as the internet, but doesn’t offer access to people connecting to the internet via a company called Cogent.
- The “Cogent Internet”; a network that looks a lot like the internet as well, but doesn’t offer access to Sprint’s network.
These events, called “partitionings”, happen very often, but are barely noticed. Most of the time this is the result of accidents, such as earthquakes or damage to underseas cables that can leave entire countries offline. But in this case, the separation of the Sprint and Cogent networks was intentional, and Sprint doesn’t want to fix the problem.
Before I get into the details of why Sprint would want to cause this problem, let’s have a look at how large the problem is. Renesys has historically offered very good data about these types of events; they have a nice summary online. The important numbers:
Sprint has approximately 100000 prefixes in their downstream cone, of which at least 1989 are single-homed (are not advertised in such as a way that they are reachable via any other provider). Cogent has over 30000 prefixes in their transit cone, of which at least 1544 are single-homed. So, in total, at least 3500 networks on the Internet have less than full connectivity right now. But due to reasons that I cited above, the impact is probably significantly worse than that.
So Sprint is intentionally leaving nearly 2000 of their (direct and indirect) customers with only partial internet connectivity, by breaking a direct connection to Cogent’s network that has only been online for two years. Why would they do this? The reason is simple: it’s about power and money.
Cogent has been driving bandwidth prices down for years, undercutting its competitors by a factor of two or more. One of the reasons they are able to keep their pricing so low is that they have direct connections to all other major networks that together make up the internet. This means that when they add new customers and traffic grows, they only need to light up some additional fiber and/or upgrade their routers; they don’t have to pay anyone other than themselves for delivering internet traffic to and from their customers. This is also called a “Tier-1” or “transit-free” network.
Cogent has been a transit-free network for about a year; Sprint and AOL were the last major networks to establish a direct connection to Cogent. These so-called peerings are usually benificial to both parties; a direct connection will keep costs down and generally offer a faster connection between both networks than when the traffic has to go through a third party network.
In this case, Sprint has probably decided that the peering was one of the reasons Cogent is able to lower their prices; by stopping the peering, they are forcing Cogent to pay a third party to deliver their traffic to Sprint. These kinds of games are played all the time between the major ISPs, and are usually resolved pretty fast, but this time neither party appears willing to budge. Sprint doesn’t appear to care that their customers can’t reach parts of the internet, and Cogent is unwilling to give up their transit-free status and is taking Sprint to court.
No matter how this turns out, every day that this continues the odds of more regulation of the telecoms sector are increasing. The DOJ already included provisions about peering in the conditions for the AT&T/BellSouth merger, and given the importance of the internet, more regulation is bound to follow when these partitionings happen more often.