Comcast has tested 10G networks at download speeds of 4 gbps.

Comcast tests 10G modem prototype at download speed of 4 gigabits per second

Comcast said it successfully tested a prototype 10G modem using the core technology that could deliver multigigabit speeds to tens of millions of homes.

In a lab test, a full duplex DOCSIS 4.0 system-on-chip (SoC) cable modem built by Broadcom delivered upload and download speeds faster than 4 gigabits per second (Gbps) powered by 10G network technology.

It’s the latest in a series of 10G milestones from Comcast. In October 2021, the company announced a successful test of a complete 10G connection using a virtualized cable modem termination system (vCMTS) powered by DOCSIS 4.0 technology.

That announcement followed major 10G milestone announcements in April 2021 of the first-ever live lab test of a 10G system-on-chip (SOC) and October 2020, of a trial delivering 1.25 gigabit-per-second (Gbps) upload and download speeds over a live production network using Network Function Virtualization (NFV) combined with the latest DOCSIS technology.

A key component of 10G, DOCSIS 4.0 is an evolutionary leap forward in the ability to deliver multigigabit upload and download speeds over the connections already installed in hundreds of millions of homes worldwide.

Comcast has shown it can get 4Gbps full duplex internet speeds.
Comcast has shown it can get 4Gbps full duplex internet speeds.

“The great strength of our smart network design is that we are able to exceed our customers’ demands today, even as we continuously evolve to meet the needs of the future,” said Charlie Herrin, president of technology, product, and experience at Comcast Cable, in a statement. “As our 10G journey continues to accelerate, customers will reap the benefits of ever-increasing security, reliability, and speed.”

10G technology builds on the work Comcast has done over the past several years to build a smarter, more virtualized network to help handle the load during the pandemic, when people are relying on remote technology more than ever.

In addition to providing a path to multigigabit upload and download speeds at scale, 10G updates will deliver near-term benefits to customers in the form of increased reliability, performance, and lower latency, the company said.

Connected by Broadcom 10G technology, the modem test utilized the DOCSIS 4.0 FDX SoC device, which Comcast demonstrated in April 2021, to pair with two cable modem chips to deliver the performance.

These were successfully connected over a lab-based hybrid fiber-coaxial network to the vCMTS operating in DOCSIS 4.0 mode. This represents the first complete network connection of all-DOCSIS 4.0 components that are required for deployment. Developers expect the demonstrated speeds — which were faster than 4 Gbps upload and download — to increase significantly as they refine technology at every level of the 10G architecture.

“With each new milestone, we get a clearer picture of how 10G technologies will unlock the next generation of speed and performance for millions of people worldwide,” said Elad Nafshi, senior vice president at Comcast Cable, in a statement.

I asked Nafshi how this test different from the earlier one.
“The big news here is that we believe this to be the world’s first test of a true 10G (DOCSIS 4.0) modem,” Nafshi said in an email to VentureBeat. “In our previous milestones that you’ve covered, we’ve demonstrated key advancements in 10G network technology (node, vCMTS), but this is the first time we’re testing the in-home device that will actually deliver these multigigabit upload and download speeds into millions of customers’ homes.”

He added, “With this announcement we’ve now successfully tested all of the key components that will be necessary to support real-world 10G deployments. With this step complete, we’re now focused on hardening these technologies as we look forward to live trials in the field.”

Dean Takahashi

Dean Takahashi is editorial director for GamesBeat at VentureBeat. He has been a tech journalist since 1988, and he has covered games as a beat since 1996. He was lead writer for GamesBeat at VentureBeat from 2008 to April 2025. Prior to that, he wrote for the San Jose Mercury News, the Red Herring, the Wall Street Journal, the Los Angeles Times, and the Dallas Times-Herald. He is the author of two books, "Opening the Xbox" and "The Xbox 360 Uncloaked." He organizes the annual GamesBeat Next, GamesBeat Summit and GamesBeat Insider Series: Hollywood and Games conferences and is a frequent speaker at gaming and tech events. He lives in the San Francisco Bay Area.