CenturyLink extends fiber reach in U.S., Europe

Over the years, CenturyLink has acquired a lot of conduit through its various deals, and now it's putting that conduit to good use with a major fiber expansion.

CenturyLink has teamed up with long-time partner Corning to deploy 4.7 million miles of fiber across the company's intercity networks in the U.S. and Europe. The first phase of the fiber overbuild is already in the books as of last month, with more than 50 cities across the U.S. connected with Corning's low loss fiber.

Andrew Dugan, CenturyLink

The first phase included 3.5 million dark fiber miles in the U.S. that CenturyLink is now in the process of selling to enterprise customers, content providers and hyperscale cloud providers, according to CenturyLink CTO Andrew Dugan.  The second phase, which is scheduled to be finished in early 2021, will add 1.2 million miles of dark fiber to CenturyLink's fiber roster in Europe.

Being able to blow the fiber through existing conduit allows CenturyLink to build out its dark fiber network without digging up the ground. CenturyLink is flush with unused conduit thanks the to the various M&A deals it has done over the years, as well as the ones that Level 3 did prior to its merger with CenturyLink.

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"We've been leveraging our conduit infrastructure that we've got from not just the initial CenturyLink build that was done through Qwest, but also the Level 3 build, the Broadwing build and the WilTel build," Dugan said. "There have been other companies that have been acquired through the combination Level 3 and CenturyLink that had a pretty significant conduit infrastructure out there."

Level 3 was ahead of its time by putting in 12 conduits when its inter-city fiber network was built. While the dotcom bust waylaid Level 3's dark fiber aspirations a bit, the unused conduit has been in CenturyLink's back pocket ever since its $34 billion deal to buy Level 3 was announced two years ago.

When CenturyLink started the North American phase, Dugan said he wasn't sure what shape the conduit would be in after 20 years, but overall it was in relatively good shape. Dugan expects the same for the conduit that will be used in Europe. Given the density and age of some European cities, it's particularly difficult to trench in conduit and fiber.

Having the existing conduit on hand also allowed CenturyLink to tailor the dark fiber routes to specific customer needs. Dugan said CenturyLink could customize routes for its private customers in order to better manage route diversity and lower latency. Dugan said hyperscalers in particular are using the inter-city fiber to interconnect their large-scale data centers in order to transfer massive amounts of information back and forth.

CenturyLink will also be able to tap into the expanded fiber routes for its internet, MPLS and wavelength services.

Dugan said that while CenturyLink has updated its fiber over the years, fiber technology has improved a great deal since some of those first installs 20 years ago. For the current expansion, CenturyLink is using Corning's fiber to create what the telco claims is the largest ultra-low loss network in North America.

"We're using Corning's SMF-28 ULL fiber, which is an ultra-low-loss, pure silica core and SMS-28 Ultra, which is also much lower loss than a lot of the fiber that's out there in the fiber infrastructure across networks in the U.S. and Europe," Dugan said. "It's much more modern and has lower loss profiles than the fibers that were put it 20 years ago."

Corning's SMF-28 ULL fiber claims to have the lowest loss of any terrestrial-grade optical fiber, while also giving CenturyLink a boost in optical signal-to-noise ratio, which can extend the optical reach at high data rates. That added scalability will come in handy as 5G, IoT, high-definition streaming and augmented reality applications and services ramp up.

"This is a big project and I'm totally excited and thankful for how CenturyLink and Corning work together on this," said Dr. Bernhard Deutsch, vice president and general manager, Corning Optical Fiber and Cable. "This would not be possible if you don't do this in a collaborative way. CenturyLink has been a pleasure to work with. Not everything always goes right, but we've helped each other and made it work."

CenturyLink's design and construction teams worked with Corning on installing the fiber, and there's more to come, according to Dugan.

"I don't think that this is the end of our fiber expansion," Dugan said. "We see pretty strong demand for our dark fiber services, and we're continuing to work with those same customers and other customers. We're going to add additional routes to this plan as we continue to find additional demand for either our own internal networks or dark fiber customers."