SDN stands for “software-defined networks” and describes an innovative network architecture that overcomes the separation of hardware and software in networks. With SDN, the control level of the network is decoupled from the forwarding level. This means that decisions about data traffic are made by a central software-based controller instead of by the individual network devices themselves.
The SDN concept distinguishes between two main components: the control plane and the data plane. The control plane, consisting of the network controller, is responsible for controlling the network and managing the network components. It configures the hardware, defines security guidelines and controls the forwarding of data through the hardware. On the other hand, the data plane is responsible for the actual forwarding of data packets and executes the instructions of the control plane.
SDN offers numerous advantages, including centralized network management, improved scalability, more transparency, security and efficiency as well as cost savings. By virtualizing network structures, SDN networks can be more flexible and easier to manage. This concept also enables the automation of processes and faster provisioning of services and applications. SDN is used by large providers and cloud operators as well as smaller networks. SDN is used in various scenarios, such as supporting DevOps initiatives, improving campus networks and automating network provisioning.