C&W Briefly Drops Peering Agreement with PSINet

It is easy to think of the Internet as something that is "out there" somewhere and that it belongs to everyone—at least everyone with a connection.

by Thor Olavsrud of internetnews.com [June 7, 2001]

Theoretically, anyone with a connection can access any part of the Internet that they desire. But that is an illusion—a convincing illusion— that was dispelled briefly earlier this week when Cable & Wireless dropped its peering agreement with struggling backbone provider PSINet.

The cancellation of the agreement left users of the C&W network unable to access IP addresses on the PSINet network and vice versa.

The two companies struck a deal Tuesday evening, and the two networks are once again communicating with one another.

Equal standing
A peering agreement is a relationship between two or more ISPs in which the ISPs create a direct link between each other and agree to route each other's packets directly across that link rather than paying fees to a third-party Network Service Provider (NSP) for transport.

But such an agreement only makes sense if the amount of traffic sent to a partner's network is about equal to the amount of traffic sends back in return.

C&W spokesman Chad Couser said PSINet was failing to meet the requirements of the contract between the two companies.

"We had seen a dramatic drop in our traffic from them," Couser said.

Couser said each of C&W's peering partners must meet three requirements: they must have an OC-48 backbone, be able to maintain an exchange ratio of 2 to 1, and have nodes in nine regions. The exchange ratio with PSINet was 3 to 1, Couser said.

"It's equitable as long as you're sending me the same amount," Couser said. "When you're sending someone more traffic than they're sending us, you're essentially giving them free access."

C&W dropped the agreement on Friday, but both Couser and PSINet spokesman Jason Thompson said the problem was not a result of PSINet filing for Chapter 11 bankruptcy protection on that day.

"There was a contractual dispute," Thompson said. "This is definitely not a result of the court actions last week."

In fact, Couser said the cancellation was looming on the horizon for a while.

"This is actually something we started talking with them about back in late February," Couser said. "It was something that they knew was going to happen for several months."

After a discussion Tuesday evening, PSINet signed a letter of intent stating that it would meet all of C&W's peering requirements. C&W resurrected the peering arrangement after the discussion.

"Now their customers can access our network and our content on that network and vice versa," Couser said.

Thompson added, "Our customers have been reconnected and the situation has been resolved to both parties' satisfaction."

Discontent or dissed content?
It is unclear how PSINet plans to actually meet those requirements. Thompson said, "They're going to continue to deliver under the terms of the contract. In peering agreements, the networks are supposed to carry an equal amount of traffic and that's what PSINet will continue to do."

Couser said simply, "I would assume that they would probably just direct more traffic to our network."

But while C&W and PSINet have ironed out their differences, there is nothing to say that such a situation couldn't occur again, between C&W and PSINet or, in fact, between any data carriers with peering arrangements. Indeed, Couser said that this incident was by no means the first time C&W has canceled a peering arrangement.

"Some networks grow, some don't grow," Couser said. "In some cases a peering relationship is sending us more traffic and they're essentially getting transport for free. When that happens, we have to reevaluate and ask them if they want to enter into a commercial agreement with us."

—End