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Telia customers are cut off from Cogent's extensive network due to a peering dispute.  (Source: Cogent Communications/Wired Threat Level)
Cogent and Telia cut each other off in tit-for-tat contract dispute

A bandwidth spat opened a rift on the internet last week, cutting off web traffic between two of the world’s larger bandwidth providers: U.S.-based Cogent Communications, and Swedish telecommunications giant TeliaSonera.

The two companies participate in a common arrangement on the internet called peering, which permits traffic to flow between major bandwidth providers by agreeing to trade roughly equal amounts of data amongst each other. When that connection is severed, called de-peering, customers from one network are unable to communicate with the other, unless they can route around the split via other, third-party networks.

According to Cogent CEO David Schaeffer, TeliaSonera peered data selectively and refused to upgrade bandwidth at some of the companies’ peering connections, causing traffic to take long, winding routes around the internet and saturating peered connections’ pipes.

“Some traffic flow was impeded and some traffic was redirected further than it needed to go,” said Cogent spokesman Jeff Henrikson. “They weren't responding to requests to comply with our contract, and we weren't left with much alternative but to terminate the contract.”

Initially, customers wanting to reach the other providers’ network were able to do so, utilizing networks from Verizon, AT&T and Level 3 Communications – but that only worked for about 12 hours, after which communications between the two mysteriously stopped.

Earl Zmijewski of internet intelligence firm Renesys says that the split is the result of one of three different outcomes:

  • Cogent stopped accepting routes to Telia from outside networks.
  • Telia stopped accepting routes to Cogent from outside networks.
  • Outside networks (Zmijewski names Verizon) stopped accepting traffic between the two.

Speaking to the Washington Post, Cogent CEO David Schaeffer denies the fact that the loss of routes had anything to do with Cogent, instead speculating TeliaSonera likely refused to pay other providers for traffic.

A representative for TeliaSonera, when contacted by the Washington Post, refused to comment on Schaeffer’s speculations but said that the two companies were in negotiations to resume connections – but that it wouldn’t consider re-peering until “TeliaSonera receives the compensation Cogent owes us.”

Schaeffer says that his company’s expansion into Nordic territories – TeliaSonera’s home turf – may have something to do with the ongoing spat and TeliaSonera’s alleged lack of cooperation.

“We've become much more aggressive,” said Schaeffer, “as we have expanded our network about four months ago in Norway and Finland.”

De-peering disputes often devolve into a game of “chicken,” where the two companies try to completely cut off each other’s traffic; the onus of response is left to whichever company has the largest customer uproar when their networks stop working and websites become inaccessible.

However, authorities on the matter are failing to find real-world examples of disruptions caused by the Cogent/TeliaSonera dispute: “I don't have any juicy examples,” wrote Zmijewski, noting that his lack of examples is both good and bad: bad, because only through big examples would the two companies be forced to settle their differences; but good, because it seems that the de-peering dispute is having little impact on the greater internet.

Zmijewski was able to find one example, though: “Martha Stewart Living is [a single-homed network] behind Cogent … If you go to Telia's looking glass as of the time of this posting, you cannot get to Martha's network. As far as Telia is concerned, Martha doesn't exist.”

“Does this mean that the Swedes are deprived of the pleasure of buying Martha's wares and sending her email?” asked Zmijewski. “Not at all. Her web site is hosted by Savvis and a customer service email address points to AOL. But if Martha's parole officer allows her to visit Scandinavia any time soon, she won't be able to reach her corporate network.”

Given that the majority of Cogent’s clients are large businesses and ISP’s with tens-to-hundreds of thousands of customers, it’s likely that Cogent’s clients are simply routing around the rift on their own, using backup connections from other bandwidth providers.

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By JoshuaBuss on 3/22/2008 12:23:02 PM , Rating: 5
kinda sucks that they use customer complaints as the main metric to fight with :|

RE: chicken?
By leidegre on 3/23/2008 4:10:19 AM , Rating: 2
You know, their like that, I remember back in the days when Telia was owned by the government, and it was a monopoly.

We call them Felia sometimes, which is a Swedish for something similar to just wrong. I'm lucky I'm not directly effected, Telia is huge in Scandinavia, but not really among our favorites, it like a Swedish AOL.

The original reason for the internet
By PrinceGaz on 3/22/2008 8:44:19 PM , Rating: 3
Wasn't one of the reasons for the internet being established was its ability to work around routing problems if anywhere goes offline. It'll always find a way to path traffic to its destination even if it means going via a very circuitous route. If major backbone providers start deliberately dropping or refusing packets they don't want, it threatens the entire existence of the internet as we know it.

Whilst customers not using either of the two companies directly involved would probably still reach any site they wanted one way or another (with a few more hops), if too many major providers start refusing packets from other providers, the whole infrastructure will collapse. Every block means more traffic routed elsewhere over more hops than it would otherwise-- increasing demand on several other links instead of the one blocked link. The more traffic which is refused, the more the extra demand impacts increasing numbers of the fewer remaining routes.

It would be like closing certain roads to certain vehicles, forcing them to use several other roads to get around the blocked direct route. Close too many roads and it won't be long before you have gridlock.

By Zoomer on 3/22/2008 10:35:07 PM , Rating: 3
The whole idea was to have way more than enough capacity to handle reroutes. Unfortunately, that isn't the case today, as any company seeking to profit maximize seeks to utilize their bandwidth capacity as much as possible.

One of three different outcomes.
By Farfignewton on 3/22/2008 10:16:33 PM , Rating: 2
Is he certain there is no chance this was the infamous abandoned ship's anchor? ;)

By TomCorelis on 3/22/2008 10:21:25 PM , Rating: 2
A little late in the game, dontcha think?

what a bloody genius
By Gul Westfale on 3/22/2008 11:02:10 PM , Rating: 2
Earl Zmijewski of internet intelligence firm Renesys says that the split is the result of one of three different outcomes:

* Cogent stopped accepting routes to Telia from outside networks.
* Telia stopped accepting routes to Cogent from outside networks.
* Outside networks (Zmijewski names Verizon) stopped accepting traffic between the two.

how on earth did he figure that out? did he learn that in special ed?

RE: what a bloody genius
By dluther on 3/23/2008 12:19:07 AM , Rating: 2
Sourcing a trace directed at Verizon's peering points to an endpoint at either networks.

dotted lines
By Are Back on 3/24/2008 12:01:00 PM , Rating: 2
What does a blue dotted line represent in the graphic?

Also, sunday or saturday morning, about 6:30AM CST, I couldn't access for about 3.5 minutes. Wonder if that has anything to do with this.

RE: dotted lines
By IckesTheSane on 3/25/2008 4:28:09 PM , Rating: 2
I'm just guessing, but they probably represent either redundant connections, or some sort of backup/non-primary line.

A squabble between Companies
By eye smite on 3/22/2008 10:10:01 AM , Rating: 3
Gotta love the he said/she said fights. lol

If its in Sweden .....
By phxfreddy on 3/23/08, Rating: -1
time for special ops
By dare2savefreedom on 3/22/08, Rating: -1
“So far we have not seen a single Android device that does not infringe on our patents." -- Microsoft General Counsel Brad Smith

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