by GCI Staff
GCI is investigating a subsea fiber optic cable break discovered earlier this week in Cook Inlet, near Kenai. Customers may have noticed a minor disruption on Tuesday as the network traffic was quickly routed to an alternate subsea fiber path.
“GCI operates in some of the most challenging terrain on earth and we prepare for situations like this,” said GCI Senior Engineer Bruce Rein, who has more than 30 years of experience working on subsea fiber optic systems and is considered an industry expert. “We’ve built our network in series of loops, essentially creating multiple network ‘rings’ around the state. If we experience a break anywhere in the ring, we can simply route traffic along another route or in the opposite direction along the ring.”
GCI owns and operates more than 5,500 miles of subsea fiber and though underwater breaks are rare, the company has restoration plans and resources in place to respond. As a precaution, GCI spends nearly $2 million per year on a deep-sea fiber repair vessel based in British Columbia. The ship specializes in repairs at depths of at least 11 meters. Ninety-five percent of GCI’s subsea fiber is located at depths over 11 meters.
For fiber repair in depths less than 11 meters, GCI retains IT Marine, a Montreal-based company that is one of a handful of companies in North America that specialize in shallow-depth repairs. The Cook Inlet break appears to be in waters approximately 7 meters deep. Cook Inlet’s extreme tides and ice coverage, currently estimated between 70-80 percent near the area of the break, add an additional level of complexity and risk to repair efforts.
“In order to successfully splice a piece of subsea fiber optic cable, the ship needs to be able to stay completely stationary for roughly 24 hours, which is extremely difficult with such a large amount of ice coverage and currents that can unpredictably move the ice pack,” said Rein. “Though precautions can be taken to deflect floating ice away from the vessel, it can still present a risk to the ship and our crews. Because the safety of the crew is our highest priority, repair efforts may need to wait until ice conditions improve. We continue to consult with experts to determine when repair operations can begin.”
When the break initially occurred, the network systems rerouted wireless and internet traffic, quickly restoring initial service interruptions. GCI’s technical response team has been actively monitoring the incident since Tuesday and continues to make system adjustments to alleviate any network congestion issues that may occur. Until repairs are completed, GCI will continue to route traffic over the alternate network path.
“We are pleased with the way our network performed in this situation,” said GCI Network Services Vice President and Chief Engineer Chris Mace. “Automatic restoration of GCI’s core services worked as designed and our team was able to quickly identify and optimize traffic routing to provide the best customer experience.”
“Because of the back-ups and redundancy built into our network, GCI has the ability to deliver uninterrupted service to our customers while we work to repair the fiber,” said Rein, who helped design and deploy all of GCI’s 5,500 miles of subsea fiber. “Most providers in the Lower 48 don’t have to contend with extreme conditions like frozen seas and extreme tides. Operating a network in these conditions can be a challenge, but GCI is committed to keeping Alaskans connected. And we’re not afraid of a challenge.”
Both the exact repair timeline and cause of the break are currently unknown. Breaks in subsea fiber are rare but can be caused by encounters with manmade equipment like bottom trawling fishing gear and ship anchors or natural causes like subsea turbidity currents, sea ice or seismic activity.