Next-generation access networks must have the ability to successfully address the next wave of video, messaging and Internet of Things (IoT), while also laying a solid foundation for the rapid creation of new disruptive services such as virtual and augmented reality applications.
The best lessons on architecting these new broadband networks can be learned from looking at data center networks. Web-scale companies like Netflix, Amazon and Google have been building high-performance data center networks for many years by taking a very different approach than what has typically been implemented in telecom and cable networks. These new architectures are highly scalable and capable of cost-effectively supporting massive surges of end-user demand. They also offer open interfaces and vendor interoperability, both of which are almost nonexistent in current telco networks. Open networks greatly benefit the network operator, allowing the use of best-in-breed components by avoiding incumbent vendor lock-in that has hindered rapid innovation within telecom. Web-scale companies use highly programmable data center architectures, opening a world of rapid service creation allowing for many more revenue generation opportunities than today’s networks afford.
Open, programmable and scalable access networks built on data center architecture principles provide the opportunity to create a platform from which producers of imaginative new operations and consumer applications can be readily connected to those who demand and consume these applications. These software-defined access (SD-Access) networks connecting gigabit-enabled homes, anchor institutions, enterprises and 5G mobile networks could offer the same transformative effect that Airbnb and Uber/Lyft brought respectively to the hotel and taxi industries by readily uniting producers and consumers.
One of the primary attributes of any data center network is programmability. This attribute not only allows third-party developers to create user-driven services to be deployed ubiquitously across SD-Access networks but provide additional operational efficiencies. Almost all aspects of data center networks are highly automated with zero-touch commissioning of resources and on-demand activation of user-driven services. To achieve this level of automation, data center networks were the early adopters of software-defined networking (SDN) technology that enabled centralized and granular control over highly distributed networking elements. This SDN-controlled approach enabled Agile and DevOps teams within Web-scale companies and their partners to focus on creating value-added applications that leverage the data center infrastructure while abstracting away the complexities associated with actually having to understand the underlying infrastructure and hindering the development of new revenue-generating and/or operationally streamlined services.
To accelerate the development and rollout of these promising SD-Access networks, the industry looked to develop an open reference architecture upon which to build these new networks, namely CORD. Central Office Re-architected as a Data Center (CORD) combines network functions virtualization (NFV), SDN and open networking principles to bring data center economics and cloud agility to the telco central office. CORD is a more modern, next-generation architecture for building and operating telco access networks. It also leverages next-generation access technologies such as several 10G PON variants, DOCSIS3.1 and G.fast. This is key as these new access technologies are set to be deployed en masse in the coming years, making them obvious targets for using CORD and SD-Access architectures.
CORD is an industry initiative started in 2015 by the Open Networking Lab (ON.Labs). AT&T and SKTelecom were the lead operator members. The goal of ON.Labs is to provide evaluation platforms for field trial on commercial operator networks.
Vendors, including ADTRAN, are collaborating with service providers and are working toward an open reference implementation for each of the many variants of the CORD platform, including use cases for residential (R-CORD), mobile (M-CORD), and enterprise (E-CORD) networks, to apply data center principles and economies to broadband access, radio access and enterprise access networks.
To highlight the R-CORD variant, its value to network operators is to enable reduced operations cost through the economies of data center architectures and bolster service delivery with the service agility of cloud providers. R-CORD supports residential broadband, connected home, and IoT expansion. When paired with highly resilient and elastic next-generation PON technologies, they support SLA-based business services, mobile back/front haul, energy distribution and smart grids. A powerful access network is needed to fast-forward to the next wave of imaginative new applications.
— Kurt Raaflaub is Head of Strategic Solutions Marketing at ADTRAN. This article exclusively appears on