Transform Your Headend: The Many Advantages of Virtualizing the Network’s Core

The core of every CATV network is the headend, which houses the active electronics behind every connected experience that business and residential subscribers rely on. All of the investments that multisystem operators (MSOs) make to prepare their outside plant infrastructure for emerging services and applications have an impact on the headend’s limited, high-value real estate. So, increasingly, MSOs are turning their attention to headend transformation, and specifically toward leveraging software-defined networks, network function virtualization, and cloud technologies to bring data center simplicity and cloud flexibility to their headend environments.

Sebastian Sassi, market development manager for Corning Optical Communications

Sebastian Sassi, market development manager for Corning Optical Communications

SDN/NFV Is Cooler

Software-defined networking/network functions virtualization (SDN/NFV) offers promising potential for space conservation and power consumption reduction on a number of fronts. By collapsing bay space currently occupied by power-hungry cable modem termination systems (CMTS) and quadrature amplitude modulation (QAM) equipment, MSOs can move to cost-effective white-box x86 servers that operate more efficiently and do the work of multiple legacy devices in a ninefold footprint reduction, requiring fewer computer room air conditioners (CRACs) to cool. These upgrades offer the chance to structure trunk cabling in crowded headends more cleanly, collapsing older runs of jumpers and copper cabling into denser, smaller-diameter fiber optic trunks that allow smoother, denser airflow and readily accommodate a hot aisle/cool aisle arrangement with short jumpers that are easy to manage during moves, adds, and changes.

The active gear for an SDN/NFV deployment also affords the operator a chance to deploy multifiber MTP connectors that support a migration path to 100GB service and beyond, plugged in to leading-edge quad small-form-factor pluggable transceiver (QSFP) optics that reduce power consumption. An MTP (QSFP+) transceiver is nearly the same size as a duplex LC (SFP) transceiver, but can supply many times the throughput capacity. Evolving the headend to MTP connectivity offers substantial density improvement, a key consideration for most space-reclamation projects. In addition to density, operators also enjoy significant power conservation, as the wattage requirement for one QSFP+ is less than what four SFP ports require. Concomitant with the savings in power is a notable reduction in cooling requirements for the switches running the QSFPs as well. Less obtrusive cabling, lower power requirements, reduced cooling requirements, and substantial space savings gained by way of collapsing bulky, power-hungry legacy access network gear in favor of switches and servers – the move to SDN/NFV sells itself.

The Power of Virtualization

Recently at a SCTE Energy 2020 plenary discussion, a headend operations manager detailed the processes his organization used to analyze where and how often they were experiencing grid power outages, and how much generator backup time they required to offset grid downtime on a location-by-location basis. While carefully evaluating their reliance on generators, and as an adjunct consideration, how much of a power load the affected headends represented – it seemed relevant to them to consider both the cost and reliability of their generator backup systems. To maintain effective, failsafe, and sustainable power delivery, they periodically test generators to make sure they are ready to shoulder the load for their average outage time of 60 to 90 minutes. For just one multi-state region, the operations manager related that they had spent over a million dollars in 2018 just to test their generator backup systems. Merely firing the generators up periodically to ensure their functional status had cost the MSO a seven-digit number through the first eight months of 2018. According to Cisco’s total cost of ownership analysis of remote PHY vs. analog deep fiber, finding ways to reduce the baseload power requirements can greatly impact an operator’s bottom line. By reducing the power required in the headend, the access network would be more survivable during an outage and a substantial operational cost reduction could be realized.

It is not lost on the MSOs that legacy service delivery models replete with bay after bay of CMTS and QAM gear requires a hefty utility bill, and they are optimistic that virtualizing some of this functionality will afford them a chance to write a smaller check to the power company. In addition to considering alternative means for supplying baseload power, to include wind and solar installations, and using passive optical network (PON) technologies for greenfield deployments to reduce the number of power-hungry radio frequency (RF) amplifiers in the field, MSOs are starting to look to virtualizing the core functionalities in the headend to chop power consumption and conserve available floorspace in already cramped headend environments.

Tipping the Scale

The move to SDN/NFV is not merely a power conservation play. While the reduced baseload power requirements for virtualized converged cable access platform (CCAP) architectures are extremely attractive, with some estimates showing as much as a 90 percent reduction in power required – a hefty savings for MSOs spending millions on fuel for generators on top of their utility bill – SDN/NFV also entails more flexible access networks, networks that leverage fiber deep architectures to provide scalable services to customers with ever-increasing bandwidth demands. SDN-enabled bandwidth is flexible capacity that can be provisioned remotely on-demand by the customer without a laborious provisioning process. Business customers can add and suspend wide-area networks and other enterprise-class services remotely with the click of a mouse and start using them on demand, and the bandwidth capacity they need for events and challenges can be provided to them on the fly, meaning the MSO sales operations teams can realize new revenues while driving customer satisfaction and creating loyal customers that represent consistent profitable business.

Cable operators face a significant challenge in the coming decade, as driving fiber ever deeper in their networks will require substantial building to stay ahead of demand for reliable, high-bandwidth services. To hold onto their competitive advantages, especially with an industry-wide push to attract and retain enterprise customers, MSOs will need to simultaneously make strategic capital expenditures on fiber distribution and density while aggressively pursuing operational savings. The utility bill will continue to be a substantial operational expense, so the time is right for MSOs to consider how virtualization strategies fit into their business models.

Sebastian Sassi is a market development manager for Corning Optical Communications. He has 20 years of telecommunications industry experience and currently focuses on helping operators transform their inside plant networks to stay ahead of demand for high-bandwidth services and applications. For more information, email or