March 2008 Archives

On March 28th at 17:52 UTC, we saw the peering link between Telia and Cogent come back up. Recently, peering disputes, especially with Cogent, tend to be all about traffic ratios: as long as both parties send roughly the same amount of traffic to each other, life is good. But when the ratios get out of whack, someone's feelings get hurt (more specifically someone's business model is threatened). Before the de-peering, we would typically see Cogent using Telia to reach around 2700 networks (prefixes). Now that count has dropped to just about 1450 networks. On the other hand, Telia used to reach approximately 7000 networks via Cogent and that number has now increased to almost 8600. So was Cogent sending too much traffic to Telia before? Did Telia then do something to provoke Cogent to turn them off (like send a bill)? We'll never know definitively, but someone blinked and the Internet is now whole again.

While this is good for the Internet, Cogent claimed that this dispute was about capacity issues and no one orders and installs new high capacity circuits in a week, especially during a contract dispute. So if there was a capacity issue, there is still a capacity issue. As a result, the situation is bound to be very fluid for the next few weeks. We'll update this blog as we analyze the resulting shifts in routing.

As in most lovers' quarrels, it is difficult to objectively evaluate the claims of the combatants. Naturally, we tend to side with the person we know best, as it's their viewpoint we hear most often and are inclined to be sympathetic towards. Both Cogent and Telia are claiming to be the aggrieved party in their peering dispute and are now making their case in the court of public opinion. We will almost certainly never know the details of their private business relationship, but we can make a few more inferences from the data. Let me state up front that, like many major ISPs, Telia and Cogent are customers of Renesys and we love them both equally. Everything we report in our blogs is based on objective analysis of our global data, independent of our own business relationships.

Cogent and Telia are having a lover's quarrel and, as a result, the Internet is partitioned. That means customers of Cogent and Telia cannot necessarily reach one another. This was not due to a configuration error or a physical cable break. This is the way the Internet works and sometimes doesn't work. If the businesses that run the show don't play nice with one another, their customers can pay the price of being cut off from parts of the 'net. At least when Pakistan mistakenly hijacked YouTube, the matter was sorted out in hours and did not require the cooperation of Pakistan. The Cogent/Telia tiff has been going on for 4 days now and only they can resolve their differences. The rest of the world can only hope for full connectivity to be restored.