Comcast says it's premature to talk about how its network virtualization strategies will take shape, but industry sources say Comcast has discussed the idea of licensing its new tech to other MSOs.

Jeff Baumgartner, Senior Editor

May 22, 2019

11 Min Read
Comcast sizing up Plan to syndicate a virtual CMTS – sources

Like it's already done with its X1 video platform, Comcast is exploring a syndication program for a virtualized form of a converged cable access platform (CCAP) or cable modem termination system (CMTS) that it could then sell and license to other cable operators, multiple industry sources tell Light Reading.

If Comcast ultimately decides to pursue that path, it could have significant competitive implications, as it would conceivably turn Comcast into a CCAP supplier and spawn a new, daunting rival in an already heated market that includes such vendors as Arris/CommScope, Cisco Systems, Casa Systems, Nokia and Vecima Networks.

That Comcast is developing a virtual CCAP is not a secret, as the operator has openly teamed with Harmonic on a project that involves Harmonic's CableOS virtual CCAP platform. That work stems from a warrant agreement, announced in the fall of 2016, that gives Comcast the option to acquire up to 7.81 million shares of Harmonic stock based on certain CableOS and other product sales and deployment milestones.

Under Harmonic's CableOS approach, the software takes care of the control, management and data plane and CMTS processing is handled by commercial-off-the-shelf (COTS) x86 servers. That product has been in production since late 2016, with Com Hem in Sweden and Ohio-based Buckeye Broadband two prime examples of early adopters. Harmonic, which aims to disrupt the CCAP market and topple the leaders with its software-powered platform, has 32 commercial deployments and field trials of CableOS underway, with more than 670,000 cable modems connected to its virtual platform. Harmonic has not announced if any of those modems reside on a Comcast network.

Sources say the vCCAP platform that Comcast is developing is a variant of CableOS that is being tailored for Comcast's network. They also say that Comcast essentially owns anything produced from the Harmonic partnership.

It's not yet known if that work will align perfectly with the CableLabs DOCSIS product interoperability specs or fork off to become a separate, quasi-standard for Comcast's networks. Notably, CableLabs recently retooled its network virtualization and software-defined networking efforts following the departure of two key execs involved in that work. CableLabs had been exploring the development of a virtual CCAP/CMTS, but it's not clear if that work is still ongoing, as CableLabs typically focuses on interoperability specs and defining actual products is a bit outside its normal scope. Plus, such activity could be rendered moot as Comcast continues to develop its own vCCAP.

Comcast's network virtualization work extends into the operator's grander plans for a next-generation network, which include Full Duplex DOCSIS, a new CableLabs spec that will support symmetrical speeds of up to 10 Gbit/s, and the MSO's associated deployment of a "Node+0" distributed access architecture (DAA) that pushes fiber closer to the home while also eliminating the amplifiers between the node and the home.

A Comcast official acknowledged that the company is keenly interested in FDX, DAA, remote PHY and network virtualization and eventually deploying those technologies and capabilities on the operator's own networks. But the official stressed that any talk of a syndication strategy involving a virtual CMTS/CCAP is premature.

The Comcast official also emphasized that DAA deployments on the company's own networks are still in their early stages, as are testing and development of the virtualization of the access network. So it's too early to suggest that the operator would pursue a licensed form of a virtualized product for other MSOs.

However, multiple people familiar with Comcast's thinking in this area say the operator is exploring the idea of offering a vCCAP under a syndication model to other MSOs, once the product is more fully developed and deployed at scale on Comcast's own network.

"This isn't a new thing," an exec with a top cable technology supplier said of Comcast's ambitions to some day market a virtual CMTS on a syndicated basis. "Frankly, Comcast has been out actively talking to other MSOs about it for a while."

The same person stressed that Comcast is not close to pulling the trigger on that idea, as the operator will want to shake it out first internally and deploy it on its own networks before moving ahead on anything bigger.

"I don't think they're anywhere near it," the source said of those syndication desires. The source added that Comcast's early discussions about a licencing model have largely been focused on the operator's current X1 syndication customers, partly to get feedback and gather information about what kind of features and capabilities they'd want to go into such a product. Comcast's announced X1 syndication partners are Cox Communications and three Canadian service providers -- Rogers Communications, Shaw Communications and Videotron.

"They've still got a long way to go in maturing it from an operational perspective before they start [syndicating] that," the source added, noting that the video service aspects of the project are much more complicated than the broadband/data side of it.

Virtualization could result in real benefits for Comcast
While Comcast's pursuit of its own virtual CMTS has some potentially explosive implications for cable vendors, Comcast stands to realize some significant benefits from the successful deployment of a virtualized network.

For starters, Comcast would save money if it can pivot away from purpose-built CCAP hardware and toward a new software-based platform that can run on less expensive COTS servers. That, in turn, could enable Comcast to emphasize the use of data centers matched with virtualization and a new remote PHY architecture that puts key electronics toward the edges of the cable network. Put together, that shift theoretically would enable Comcast to significantly eliminate the real estate needed for traditional headends and secondary hubs, not to mention the costs required to power, cool and maintain those facilities.

But Comcast would also have to deploy an expensive enterprise-class Ethernet switch in its remote PHY solution, which, according to one source, could pop the costs back up to what a port in a traditional CMTS costs today.

"I think they've been learning the hard way that that's not as easy as they thought it would be," a source familiar with Comcast's virtualization effort said.

And it's not a platform that would be deployed overnight, as it will more likely be rolled out on a staggered, cap-and-grow basis, with greenfield builds being the most logical starting point. "It won't be a hard cut," the source said.

Jeff Heynen, research director for broadband access and home networking at Dell'Oro, said it's logical from a technology and operational standpoint for Comcast to, in a sense, go it alone with respect to network virtualization. Comcast, he said, might have no other option but to push ahead, as it's essentially on an "island" with respect to its current network trajectory compared to other MSOs around the world. Plus, he said, it would behoove Comcast to assume as much control as possible of the costs and to establish a predictable path for how it makes this critical transition.

Comcast's commitment to DAA and FDX dwarfs any being made by other cable operators. Comcast may also be moving at a speed that exceeds what it needs from standard- and specification-setting industry organizations that typically require feedback and buy-in from multiple cable operators before things can be agreed upon and pushed forward.

"For Comcast and the scale and type of network they want to pursue, it makes sense [for them] to have control over the software and the hardware and all of those aspects," Heynen said. "There's no question that Comcast is the most aggressive with Full Duplex DOCSIS and DAA -- no other operator is going down that path as aggressively. Comcast is the only one that has said we're on this path to Full Duplex."

He said it's too early to say if Comcast would find much success with a syndication strategy, though Heynen speculated three years ago that such a possibility could someday emerge in the wake of the original Comcast/Harmonic CableOS-focused warrant agreement.

"They [Comcast] certainly could license it, but I don't know what kind of reception they would receive from the larger cable operator community," Heynen said, noting that syndication is likely far down the list on Comcast's current priorities with respect to network virtualization.

Next page: Syndication viewed as a 'tall order'

Syndication viewed as a 'tall order'
Even if Comcast ultimately pursues a syndication model with its vCMTS/vCCAP, it could still be many months and possibly years before that part of the project is ready to go, according to people familiar with the concept.

"It's a pretty tall order," said an engineer with knowledge of Comcast's plan to deploy a virtual platform on its own networks and later attempt to license it. "It's a good thought; but it's a while away from becoming a sellable product."

The same source added that Comcast has the resources and engineering wherewithal to pull it off, but believes it could be 2021 or 2022 before a syndicated version of the product would be ready for prime time.

Looking back, Comcast spent a good deal of time developing, deploying and refining X1 before it began to gear up syndication activities for that product. Comcast introduced X1 in Boston back in 2012 and the licensing discussions for X1 didn't heat up until 2014.

Although syndicating X1 wasn't an easy task for Comcast, applying that model to a virtual CMTS is a much larger, more complicated undertaking since it deals with the access network and many more moving parts, sources said. In addition to the software and the COTS servers, there also needs to be an end-to-end network to run them on, as well as critical and stringent latency and jitter requirements.

Operating and supporting a virtual CMTS product is a "far cry" from designing a system like X1 and providing support for it 24/7 to other cable operators, an MSO source said. "A different level of support is needed. The bigger question is: Does Comcast really want to be in that game?"

Only Comcast knows for sure. But syndication has clearly become an important piece of the puzzle for Comcast as it attempts to boost financial returns and drive more economic scale into the technologies, products and services it develops. "The best way to do that is to own it," says a long-time exec with a top cable network supplier who has worked with Comcast and other major MSOs.

In addition to X1, the Comcast Technology Solutions unit of the company syndicates voice services, as well as the "Xmeter," a network troubleshooting tool for field techs. Comcast showed off a couple of its portable meter products, both running RDK-B open source software, at last year's SCTE Cable-Tec Expo in Atlanta.

Another big question is whether MSOs, including existing X1 syndication partners, would buy in, because they are already working with their own CCAP suppliers and some are moving downstream on trials and deployments of next-gen access network strategies and distributed architectures that differ from Comcast's focus on N+0.

"It's hard to imagine anyone else in cable even thinking of attempting this, except for maybe Liberty Global," said Alan Breznick, cable/video practice leader of Light Reading. "Who else would risk upsetting all their long-term vendor relationships to pursue such a costly quest, even if it pays off in the long term?"

Given the still-lengthy timelines on deployment and the potential for Comcast to offer virtual CCAP products under a syndication model, it's difficult to gauge how (or how soon) this could have a material effect on the existing crop of CCAP vendors. At the very least it seems that it could, at some point, make it more difficult for Comcast's current CCAP suppliers, such as Arris and Cisco, to serve as key cogs in the MSO's future plans. Likewise, it could make it even more difficult for a vendor like Casa to break in at Comcast. That situation would, of course, be amplified if any other cable operators opted to syndicate Comcast's platform.

By the same token, this could be a big boon for Harmonic if its partnership with Comcast is successful. And if that work does turn into scaled deployments at Comcast and possibly other cable operators, Heynen wonders if that could, in turn, force other suppliers to consider integrating CableOS into their hardware.

So, it doesn't necessarily all add up to spell doom for other CCAP suppliers. But it certainly could diminish their role in the future Comcast network in the years ahead and likewise weaken their position to a level not seen since the DOCSIS era got underway in the mid-1990s.

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— Jeff Baumgartner, Senior Editor, Light Reading

About the Author(s)

Jeff Baumgartner

Senior Editor, Light Reading

Jeff Baumgartner is a Senior Editor for Light Reading and is responsible for the day-to-day news coverage and analysis of the cable and video sectors. Follow him on X and LinkedIn.

Baumgartner also served as Site Editor for Light Reading Cable from 2007-2013. In between his two stints at Light Reading, he led tech coverage for Multichannel News and was a regular contributor to Broadcasting + Cable. Baumgartner was named to the 2018 class of the Cable TV Pioneers.

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