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. 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.
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.”
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
cancelled 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.”
