Blackout Shows Net's Fragility
It doesn't come easy wrote to mention a ZDNet article discussing a recent outage between Level 3 Communications and Cogent Communication. A business feud inadvertently highlighted the fragility of the Internet's skeleton. From the article: "In theory, this kind of blackout is precisely the kind of problem the Internet was designed to withstand. The complicated, interlocking nature of networks means that data traffic is supposed to be able to find an alternate route to its destination, even if a critical link is broken. In practice, obscure contract disputes between the big network companies can make all these redundancies moot. At issue is a type of network connection called 'peering.' Most of the biggest network companies, such as AT&T, Sprint and MCI, as well as companies including Cogent and Level 3, strike "peering agreements" in which they agree to establish direct connections between their networks. "
It's very true, and anyone can see how a few big companies basically make the net work in north america. Simply do traceroutes to various big web sites, and you'll notice the packets always go across the same networks. The biggest one seems to be alter.net (MCI), with others including Level3, above.net, AT&T and UUnet. Basically you remove any of these and the North American part of the Internet would be in chaos. The problem is because most ISPs do the same thing. They pick a primary provider, and get a backup one. The problem is they all pick the same few primary companies, and their backup links are much smaller pipes.
NANOG has been on fire with posts about this issue over the past few days. The following two from Leo Bicknell do a good job of explaining why this sort of thing would happen, why nobody in particular is The Bad Guy[tm], and why this issue has no relevance to the issue of internet resilience in the case of natural or manmade disaster:
. html. html
http://www.merit.edu/mail.archives/nanog/msg12302
http://www.merit.edu/mail.archives/nanog/msg12350
About 4 months ago I got a call from a sales critter at Cogent saying "We will knock 50% off of the price you are paying for your L3 connectivity if you drop them and come be our customer." I was kind of surprised at the boldness of this proposition because they were specifically targeting current L3 customers. I was even more surprised to find out from others that this sales pitch from Cogent was company wide. Of course this pissed off L3 and that was the start of this pissing contest.