Software-defined Networking(SDN) is a new networking technology that has emerged in the last ten years or so and is presented as a revolutionary improvement to current technology.
SDNis an architecture aimed at making networks more flexible. The goal of SDN is to enable cloud and network engineers and administrators to quickly respond to changing business requirements through a centralized controller.
SDN defines a software layer that acts as a barrier between network elements and the network administrator (who configures and installs them). This software layer provides network administrators with the ability to control their network devices through a manual software interface instead of having to manually configure the hardware and physical effects of the network devices.
SDN controllers centrally manage network service devices whenever they need to, regardless of the type of connection between the server and the device.
How Does SDN Work?
Initially, SDN focused only on separating the network control plane from the data plane. The control plane makes decisions about how data packets will travel through the network, while the data plane performs the task of moving packets from one place to another.
A packet arriving at a network switch is directed to its forwarding destination by rules built into the switch’s proprietary firmware. These packet processing rules are sent to the switch from the central controller.
Switches—data plane devices—query the controller to receive the necessary instructions and routing rules and provide the controller with information about the traffic it is handling. A switch will send a packet to the same destination on the same path and process all other packets in the same specified way.
The operating mode of an SDN is often called adaptive or dynamic, in which a switch makes a routing request to the controller for a packet that has not been specifically routed. This process differs from adaptive routing mechanisms in traditional networks.
In traditional networks, switches send routing requests through routers, and the router’s routing algorithm operates based on the network topology (network topology) without going through a central controller.
Benefits of SDN?
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Direct Setup: SDN network policies are set directly instead of control functions being detached from forwarding functions, allowing the network to be programmatically configured by open-source or proprietary automation tools, including OpenStack, Puppet, and Chef.
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Centralized Management:Intelligent Networks are logically centralized in the control software of the SDN maintaining a system-wide view of the network, as an application.
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Reduced CapEx:SDN has the ability to limit the need to purchase network hardware, based on ASIC and instead support pay-as-needed models.
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Reduction OpEx: SDN allows control over the network algorithms of network components (such as routers, switches, and hardware), making network design, deployment, management, and expansion easier.
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Automated capabilities optimize the delivery and coordination of service availability and reliability by reducing overall management time and human errors.
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Provides flexibility: SDN helps organizations quickly deploy new applications, services, and business models, potentially generating new revenue streams and more value from network.
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Enabling Innovation:SDN enables organizations to create new types of applications, services, and business models that can provide new revenue streams and more value from the network.
Challenges with SDN?
Security is both a benefit and a concern with SDN technology. The central controller of SDN uses a single vulnerability which, if targeted by an attacker, can cripple the entire network system.
