The owner of 30,000 kilometres of cable network linking Australia and New Zealand to the US, Southern Cross said a "hardware failure" in its network located in California -- not the undersea cable itself -- was the cause of the downtime. However, traffic was re-routed to its secondary line this morning as soon as the failure was detected.
The undersea 'loop' network automatically switched traffic to a secondary line within "milliseconds" of the fault, said Ross Pfeffer, sales and marketing director, Southern Cross.
"As we have a loop network only one part of the network has gone down," said Pfeffer.
One side of the network usually carries all the Internet traffic, while the other is left empty as a redundancy measure, he said. The hardware failure saw all traffic switched to the standby line, he explained.
"Our customers can configure their traffic to travel over remaining parts of the network.
"So it really comes down to how customers have configured their network for these situations," said Pfeffer.
Pfeffer said work was underway to repair the network but could not say when it would be fixed. "We don't have a dual outage or anything like that. There's still a path to the US. We're just working on bringing it back to being a protected network."
Macquarie Telecom, which purchases Southern Cross network capacity, said its engineers responded to the issue by re-routing Macquarie traffic via an alternate supplier.
Macquarie customers may have had difficulty accessing sites hosted in the US for less than an hour this morning, according to Denis Rowe, Macquarie Telecom spokesperson.
"So the issue's been resolved as all our links back to the US have been restored.
"But because they're smaller links, there may be some speed congestion," Rowe said.
iiNet and WestNet are other Australian Internet Service Providers to have purchased Southern Cross network capacity.