Comcast slashes time to find fiber cuts from 2 hours to 2 minutes

Comcast is putting outdated optical spectrum analyzers to work to boost local network reliability, using them as part of a new performance monitoring system which can slash the time it takes to pinpoint fiber cuts from two hours to less than two minutes.

Venk Mutalik, the Comcast engineer who led development of its new XMF platform, told Fierce spectrum analyzers are typically used in reconfigurable optical add-drop multiplexer (ROADM) devices to slice light and send traffic down different paths as needed. But he noted these analyzers quickly become obsolete, as new iterations are released each year.

Through the XMF platform, though, Mutalik and Comcast have found a new use for older-generation analyzers, deploying them not to route light but simply to observe and report on the condition of individual fibers in local networks. He described the system as something akin to sonar or CCTV monitoring for the network.

“If you can measure the time between the reflections you can now estimate what that distance was" to home in on where an imperfection is, Mutalik explained. “Every time a fiber has been cut, we immediately know how long the fiber was originally and how the fiber has been cut right now, and then there is a warning that goes out to our ticketing and dispatch and then they’re able to locate the fiber that is cut” to make repairs, he added.

In addition to real-time monitoring, Mutalik said the system can also provide analytics over a longer period of time to proactively track fiber degradation and help it maintain service-level agreements with customers.

Comcast Cable SVP of Next Generation Access Networks Elad Nafshi told Fierce the new system is a key step on the operator’s road to 10G.

“As we continue to push what we call DAA, or distributed access architecture, which ultimately digitizes all of the access fiber links we have…knowing and understanding what goes on in those fibers becomes even more important,” he explained. “We see this as one of the critical efforts that we have. So that as we make our network even faster and more capable, we can’t lose track of the reliability.”

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Nafshi said Comcast is currently in the process of rolling out the XMF capabilities nationally. He added the new platform goes hand-in-hand with Comcast’s other network management and monitoring initiatives, including the rollout of its Octave traffic modulation tool in 2020.

“There isn’t a silver bullet for network reliability,” Nafshi concluded, but noted Comcast is working on stitching together insights from its various tools to get the greatest amount of visibility into the customer experience.