Everyone knows that broadband networks saw a huge increase in traffic during 2020 because of Covid. But it wasn’t just downstream traffic that increased. It was also upstream traffic that carries things such as video conferencing apps.

According to some traffic numbers that Comcast released about its network, peak downstream traffic in 2020 increased about 38% over 2019 levels, and peak upstream traffic increased about 56% over 2019 levels.

The amount of video communications traffic from platforms such is Zoom is still a small 4%-5% of the total consumption on Comcast’s access network. But this is an increase from about 2%-3% in 2019, according to Elad Nafshi, Comcast’s SVP of next generation access networks.

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Besides an increase in upstream traffic from videoconferencing applications, Nafshi pointed out there’s also the natural, corresponding increase in upstream traffic that comes with an increase in downstream traffic. 

Elad Nafshi, Comcast
Elad Nafshi

Comcast does a variety of things to improve the capacity of its upstream networks. One of these is a no-brainer: it deploys more fiber, which offers symmetrical downstream/upstream speeds. 

Comcast’s footprint of 750,000 miles of connectivity is comprised of a combination of fiber and coaxial cable. According to the analyst firm Cowen, Comcast has about 150,000 route miles of fiber, an estimate based on public disclosures and analyst insight. A Comcast spokesperson said this number isn’t precisely accurate, but he didn’t have any public update.

The company did say that from 2017 through 2020, it built an additional 39,153 route miles of fiber.

Boosting upstream via software innovation

Another way that Comcast improves upstream capacity on its network is to deploy next-generation virtualization and automation technologies. Nafshi’s team leads this work. It’s been using distributed access architectures (DAA) to digitize the access network. One way that DAA helps is that Comcast doesn’t have to keep “splitting nodes” in order to increase upstream capacity. Node splitting requires adding additional space for more equipment. And it also costs more money for power and cooling.

Nafshi went into detail about Comcast’s DAA work on a recent FierceTelecom virtual event, which is available for free, on demand.

As part of its software and virtualization efforts, Comcast created another technology platform called Octave. This software is programmed to detect when modems in customer homes aren’t using all the bandwidth available to them as efficiently as possible. The Octave software automatically adjusts bandwidth to improve both downstream and upstream capacity.

Comcast engineers dramatically accelerated the completion of Octave in response to the pandemic, which enabled the company to increase upstream capacity by up to 36%.

RELATED: During COVID-19, Comcast ups its virtualization game from core to cable modems with AI and ML

“Octave allows us to collect data in real time and use artificial intelligence and machine learning,” said Nafshi. “Rather than set the modulation at the market level, we’re doing it at the subscriber level to truly optimize the capacity that every customer is getting.”

He said Comcast is having good success adding upstream capacity by relying on software innovation.

“The team has driven bleeding-edge innovation where we needed it the most,” said Nafshi. “Being able to drive software innovation and be able to act on this with the level of sophistication is what make us truly unique.”


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