SDN is a network architectural model that allows a network to be centrally controlled using either software applications or application programming interfaces (APIs).
Considerable amounts of data traffic, intricate network structures, and growing demands to improve network performance have conspired to phase out the traditional network management approach. Traditional networking uses integrated hardware and software to direct traffic across a series of routers and switches.
Software-defined networking (SDN) was developed to virtualize networks by separating the control plane that manages the network from the data plane where traffic flows. By separating the software from the hardware, network operators can introduce a variety of innovative services.
APIs communicate with underlying hardware infrastructure and direct traffic on the network. SDN algorithms tell a network what to do in response to changes in the network or dynamic flow pattern changes. With SDN technology, operators can configure networks to scale.
When using SDN, an operator can manipulate network traffic from a central control console without changing the settings of individual switches. This grants operators the power to change network rules and block certain packets, among other things, with virtually complete control.
SDN is essential to cloud computing and its multi-tenant architecture because it permits more flexible and efficient control of traffic loads.
Security, policies, restoration, and bandwidth management can be differentiated between networks and optimized with the central control SDN provides. The operator also gains the ability to capture a holistic view of the network.
Software-defined networking is also used in Network Function Virtualization or NFV. NFV is the concept of replacing specialized hardware like firewalls and load balancers with software (VMs, containers) running on off-the-shelf server hardware.
Some enterprises use SDN to connect data centers to public cloud servers, designing a compound cloud network that includes microsegmentation or complex scaling abilities. Other SDNs can assist in managing the constant stream of traffic from the internet.