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Undersea cables keep global enterprise networks afloat

Subsea cabling is out of sight, but it shouldn't be out of mind. Many organizations don't realize just how dependent they are on underwater fiber to stay online and in business.

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Somewhere in the Atlantic Ocean, a ship drops anchor. The heavy piece of metal falls hundreds of feet to the ocean floor, where it hits a subsea fiber optic cable and severs it. Businesses that depend on the cable for intercontinental communication could -- without sufficient redundant capacity -- lose their primary means of connectivity for weeks. That can mean a lot of money down the drain.

In an increasingly global economy, basic business communications and financial transactions happen over networks. And if that traffic is going to another continent, country or region where it has to cross a major body of water, it travels via expensive undersea cables laid on the bottoms of oceans, lakes and seas.

Most organizations don't spend a lot of time thinking about it, but submarine fiber optic cables deliver 99.8% of all intercontinental communications, according to telecommunications market research and consulting firm TeleGeography. Considering the sheer volume of traffic they carry, the vulnerability of undersea cable systems is worth losing sleep over.

"It's only when something fails that we start backtracking and saying, 'Wait a minute -- why didn't I think about creating a backup plan?'"  says Adam Janota, vice president of global marketing at cloud-based service provider Console. Janota was formerly the senior director of global networks at data center colocation company Equinix, where he witnessed the impacts of undersea cable outages firsthand.

When a subsea cable sustains damage, a specialized repair crew must find the break and splice in a new piece of extension fiber. "There is some time when you're down, and you're down hard," Janota says.

And trouble can come in many forms under the sea -- from boat anchors and fishing trawler nets dragging cables along with the catch, to natural disasters, aging cable infrastructure and even fish bites. Then there's the high-profile threat of security breaches or terrorist attacks.

High seas, high stakes

Undersea cable is literally out of sight, but it definitely shouldn't be out of mind. Any enterprise with international customers, partners or employees needs to understand its reliance on subsea fiber and decide if it needs a backup plan -- even if it hinges on satellite connections, a much slower and more expensive alternative.

It's only when something fails that we start backtracking and saying, 'Wait a minute -- why didn't I think about creating a backup plan?'
Adam Janota, VP global marketing, Console

If you're highly dependent on information circulation for your business, undersea systems are critical, says Nicole Starosielski, author of 2015's The Undersea Network -- which she wrote after traveling for six years studying the history of the cable network and the forces that have shaped it -- and assistant professor at New York University. And while enterprise networking pros understand that voice and data traffic delivery is increasingly transoceanic, many others assume that those bits and bytes are transmitted wirelessly.

"Any company that really depends on international links should know how their traffic is being routed," Starosielski says. "If they're setting up their own network, then they should make sure to have diverse circuits, multiple paths. Because they can't assume that those [undersea cables] are always going to be 100% up and working."

Subsea cable disruptions happen a lot -- as frequently as every three days, according to TeleGeography. Because of redundant routing, however, enterprises don't necessarily know when one occurs. After an outage, users may regain connectivity in milliseconds, minutes, hours, days or weeks -- depending on the availability of alternate connections.

"The moment happens when something goes down and your user base, your network users, your boss, your CEO come to your office and say, 'Hey, why can't I communicate? Why can't I send an email? I'm waiting for an order form. I'm waiting for an important call,'" Janota says. "You want to be able to answer those questions." 

Detecting and fixing damage typically falls to service providers. Akshay Sharma, research director for Gartner's Carrier Network Infrastructure group, says with sufficient redundancy and capacity, the effect of a subsea cable cut on network performance should be minimal. But he points out that bandwidth needs are rapidly increasing.

"With the growth of internet traffic -- especially with video consuming over half the internet -- the effect [of a subsea fiber outage] can be severe from a congestion point of view," he adds.

Main arteries of the internet

Internet traffic on terrestrial networks is highly distributed, but under the sea, not so much. Fewer than 400 undersea cables carry nearly all telephone and internet traffic across the world's oceans -- providing 294.6 Tbps of capacity to global users in 2015. Of that traffic, 76 Tbps travels to the United States alone, an amount that TeleGeography expects to grow to 108 Tbps in 2016.

In the past few years, the largest content providers have become the biggest users of undersea capacity, and they will become even bigger customers of long-haul capacity as they expand their own internal networks, according to TeleGeography. Recently, some of those companies -- among them Google, Facebook, Microsoft and large global financial institutions -- have begun financing and building their own global networks that include undersea cable routes. They are expected to outspend carriers in the next few years.

The vast majority of enterprises, however, don't buy capacity directly on undersea cables, relying on their service providers to get their global voice and data traffic where it needs to go. But they end up paying for it one way or another, says Brian Chee, IT specialist at the University of Hawaii's ALOHA Cabled Observatory. The underwater observatory -- the world's deepest, at three miles below the surface -- collects important oceanic environmental data via a retired cable, which AT&T donated to the university for $1.

"Most corporations and most individuals don't understand that undersea cables are insanely expensive," Chee says.

According to TeleGeography, cable costs vary based on distance, with a new trans-Atlantic cable running, on average, around $250 million to $300 million. Engineers wind the fiber -- wrapped in a shark bite shield and large braided conductor -- deep in the hull of a specialized ship. The vessel then runs a large plow along the bottom of the seabed and drops the cable in the resulting trench or, in other places, simply lays it directly on the ocean floor.

When a subsea cable sustains damage, a specialized repair crew must find the break and splice in a new piece of extension fiber -- a process that takes time and hundreds of thousands of dollars, Chee says.

What lies beneath: Security risks

TeleGeography estimates that 100-150 subsea cable failures occur every year -- with two-thirds of those disruptions due to damage from fishing gear and ships' anchors. Security vulnerabilities are also cause for concern. That's why, on nautical charts, the exact locations of cables remains unmarked -- indicated only by large no-anchor zones.

As for cable landing stations, according to Chee -- who used to work for the federal government's Office of Information Security -- the Department of Homeland Security has designated them sensitive national resources.

"They are not marked on the maps. We are not allowed to tell people exactly where they are," he says. "The entrances to those landing stations are literally vault doors."

Still, when he considers undersea cables, Chee says terrorism is low on his list of concerns.

"The chances of one of our enemies being able to get to and destroy one of these cables is relatively low," Chee says. 

Starosielski agrees, adding that without a high degree of familiarity with the network, terrorists wouldn't know for certain who would lose connectivity if they cut a given cable, making a targeted strike difficult.

But she and Janota both say enterprises -- even those who rely entirely on service providers to operate their international networks -- should find out where their data travels geographically, to anticipate how geopolitical upheaval might affect normal operations.

"A lot of subsea cables going from Europe to the Middle East, for example, go through the Suez Canal," Janota says. "The government in Egypt has effective control of all of [that] traffic going … from Europe to Asia."

Espionage presents another concern. For example, Janota says anyone able to hack a subsea cable between the United Kingdom and the U.S. could access a vast number of calls, emails, messages, financial transactions and video communications traveling between those two countries.

Fail to plan, plan to fail

Starosielski says that while undersea cable security still needs improvement, monitoring practices have gotten stronger, with tracking devices alerting network operators to the presence of large ships near cables, for example. But despite these measures -- as well as strict no-anchor zones and legal ramifications for those who sever subsea cables -- accidents still happen. 

Having multiple subsea cable connections, multiple entry points and multiple fiber routes allows physical diversity in case of any type of disruption, whether it comes from  an earthquake, hurricane, tapping, spying or hacking, Janota says.

Subsea cable map, TeleGeography
TeleGeography counts 354 existing and planned subsea cables worldwide. Map courtesy of TeleGeography.

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This was last published in September 2016

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