SDN stands for Software-defined networking. It is a network architectural model that enables programmatic administration, control, and optimization of network resources. The feature of the traditional network architecture model fails to combine the demands of current business IT.
Organizations needed network infrastructure that enables the adaptability to scale and provide dynamic computing environments based on promptly growing technology and business landscapes.
SDN produces a broad array of business benefits. Separation of the control and transport layers increases adaptability and stimulates time-to-market for new applications.
The capacity to acknowledge more swiftly to problems and outages increase network availability and programmability creates it simpler for IT organizations to automate network functions, decreasing operating costs.
The main objective of SDN is to address several challenges in traditional networks. In traditional networks, forwarding decisions depend on set rules over which network services have minimal control.
SDN enables the programming of network behavior in a centrally controlled aspect through software applications utilizing open APIs. By opening up consistently closed network platforms and implementing a common SDN control layer, operators can manage the entire network and its devices consistently, regardless of the complexity of the underlying network technology.
SDN is constructed on logically centralized network topologies, which allows intelligent control and administration of network resources. Traditional network control approaches are distributed. Devices function independently with limited knowledge of the state of the network.
For instance, packets destined for a similar network endpoint are directed along a similar route and managed similarly. If there were traffic congestion at some given point along the route, all traffic causes congestion although an alternate, less congested path can be available.
SDN is also a basic enabler for telecommunication networks to shift from traditional discrete hardware-centric deployments to cloud-based deployments, with critical network components deployed using software running on appliances developed using off-the-shelf elements.
OpenFlow is the technology used in an SDN environment, representing the communication link between a controller (control plane) and forwarding switches (data plane).
It is provided primarily by the Open Networking Foundation (ONF), OpenFlow eliminates the whole control plane from the network equipment, allows broad vendor choices and economical deployment.
Within an SDN environment, the software running on SDN Controllers allows the higher method orchestration and programmability of the network.
The SDN Controller generally uses OpenFlow to program the forwarding table of the data plane switches and manage how to route connections to manage the suitable tasks for the applications.
SDN links with another technology, Network Functions Virtualization (NFV). NFV provides the capability to virtualize appliance-based network functions including firewalls, load balancers, and WAN accelerators.
The centralized control that SDN supports can efficiently handle and orchestrate virtual network functions that are enabled by NFV.