Cablecos inch toward the cloud with virtualized CMTS

When it comes to network virtualization and cloud, cable companies aren’t sitting on the sidelines.

Most are anxious to reap the benefits of moving workloads to the cloud because it adds efficiency to the network, lowers latency and makes it possible to offer new services more quickly. But at the same time, cable companies face many of the same challenges that telcos face. 

For example, they have to determine which functions to move to the cloud, whether to use a private or public cloud, and how to find skilled workers that know how to operate in a cloud environment.

“Like most service providers, I think the reasons for moving to the cloud are very similar,” said Jeff Heynen, vice president of broadband access and home networking at Dell’Oro Group. “Operators are trying to make their networks more efficient by separating and centralizing control plane functions from data plane functions.”

Virtualizing the CMTS

One of part of the cable network that is being revamped is the cable modem termination system (CMTS), which is located in the cable’s headend and is used to provide high-speed data. Heynen said that primarily Tier 1 cable operators are involved in the larger virtualized CMTS (vCMTS) deployments and most are on-premise. However, he added that ultimately as cable operators add more distributed access architecture (DAA) under the vCMTS platform, they will push more of that functionality to the cloud so workloads can be processed more efficiently.

Charter Communications announced March 20 that it will use Harmonic’s CableOS platform to rollout a virtual CMTS (vCMTS) system. Comcast also has said it is using Harmonic’s CableOS platform for vCMTS.

In addition, Drew Davis, AVP of wireline access engineering at Cox Communications, said at the Cable Next-Gen Technology and Strategies conference in Denver in mid-March that Cox will be launching vCMTS in the next 12 to 18 months.

This move to the vCMTS is a big step for cable operators, which traditionally have deployed purpose-built CMTS equipment.

“In the HFC [hybrid-fiber coax] world, the CMTS is the center of the world. You have to get it right,” said Chris Bastian, CTO of the Society of Cable Telecommunications Engineers (SCTE).

Bastian added that one of the reasons for virtualizing the CMTS is that it makes it easier to upgrade from DOCSIS 3.1 to DOCSIS 4.0, plus it adds redundancy to the network. However, he said that moving to vCMTS also requires interoperability testing, which SCTE does for the cable companies. Bastian said that CableLabs, a non-profit research and development lab created by U.S. cable operators, handles the specifications and SCTE, which is a subsidiary of CableLabs, handles the testing and training.

“Interoperability is important,” Bastian said. “Once the CMTS is virtualized you have to deal with dozens of different vendor modems.”

Public or private cloud?

While some cable operators grapple with the vCMTS, WideOpenWest (WOW!) has deployed its IP video architecture in a hybrid-cloud environment.

Blair Day, SVP of network engineering at WOW! said that WOW! currently puts the more resource-intensive and latency-sensitive applications in the company’s private cloud and puts other functions in the public cloud.  

WOW! determines which functions go where by looking at cost, connectivity and security.

“We continually explore the economic and operational tradeoffs between the two for each compute task,” Day said. “We will also use the public cloud in a true hybrid sense for a given application where we might failover from private to public for disaster recovery."

However, he noted that some of WOW! software-as-a-service (SaaS) partners only offer a public cloud option, so the company is required to use the public cloud for those services.

One advantage of working with a SaaS provider is that they can bring the cloud to the cable operator even if the cable company doesn’t have that capability yet.

Joe Lancaster, chief strategy officer at OpenVault, a SaaS provider, said that many cable operators have certain services that they want to reside in a private cloud because the cable company wants to control the environment. Other services are better for the public cloud, because they can get results more quickly without spending as much money. “Flexibility is key,” he added.

Finding skilled workers

The cable industry isn’t immune to the challenge of finding engineers that can bridge the gap between the legacy cable world and the cloud world.

Day said that WOW! has developed programs to “upskill” its employees so they are knowledgeable about the cloud. “Upskilling cannot be an afterthought,” he said, adding that WOW! believes that most technology positions will at least need to be “cloud-aware” in the next three to five years and beyond.

SCTE also provides training for cable engineers and software developers to make them more skilled at cloud services. However, Bastian said that the virtualization of the network and the move to the cloud has an impact on the field workforce too. “You have to train them and equip them with the right tool sets,” he said. “It’s not just the network device that is changing, but all the tools are changing as well.”