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Network functions virtualization (NFV) and software-defined networking (SDN) have emerged into the spotlight for telecom operators and other service providers as they make their transition to a cloud-based world. What are they and why are they important? It’s important to understand that NFV and SDN are highly complementary but they perform distinct functions for operators’ infrastructure. To appreciate their value we first must look at the problem statements and opportunities that they target. Existing telecom infrastructure is optimized for reliability, long-lived applications, and fairly predictable traffic demand. To compete in the future, however, these networks need to evolve in a way that mirrors the newer market entrants – cloud hosting providers, over-the-top (OTT) players, and non-traditional players like capacity wholesalers and internet exchanges. These new entrants are well positioned for the new world of unpredictability, web-scale traffic, equipment upgrades at the pace of Moore’s Law, and an ever-increasing array of end-user applications. Telecom operators must follow suit, making their networks more programmable, more interchangeable, more open and more scalable. Enter NFV and SDN. Traditional networks are built on dedicated “appliances”, or routers, firewalls, mobile packet cores, storage arrays, and other components made up of proprietary hardware and software. In addition, the two major functions of many devices, the “data plane” (the application traffic) and the “control plane” (the communication messages among devices to route and manage this traffic) have historically been conjoined and inseparable. NFV and SDN fundamentally change this paradigm. NFV transforms the dedicated appliance model by separating the software from proprietary hardware by hosting the software on standard or “white box” servers and switches. It also defines a series of application-program interfaces (APIs) that are open and pluggable across different vendor environments. This liberates operators from strict vendor roadmap dependencies and also introduces the concept of “service chains” in which the application can gracefully span across devices, vendors, and cloud stacks – greatly easing operational demands and shortening time-to-revenue. SDN separates the control plane from the data plane. Rather than having “islands” of switching, routing and other session traffic, SDN creates a holistic catalog of infrastructure resources and then assigns workloads dynamically based on the application priority and behavior characteristics. The result is significantly better network utilization, management simplicity, and shortened turn-up time. So now telecom operators have some powerful tools to participate in an increasingly competitive environment for end-user applications, and the value chain that is associated with it. NFV and SDN represent a complete transformation not just of the infrastructure, but of the way applications are fundamentally addressed. In the past the applications had to adhere to the requirements of the network; with NFV and SDN the network adapts to the applications. What are NFV and SDN, and why should I care? |
