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What is Software-Defined Networking and Virtual Networks in Physical Networks

In This Article, we'll discus the Software-Defined Networking and Virtual Networks in Physical Networks

What is Software-Defined Networking?

Network virtualization and Software-Defined Networking (SDN) stem from a common pursuit- the goal of greater network agility- and still share certain traits:
  • Both use software to recreate key components of networking infrastructure

  • Both separate the control plane (the part of the network that manages and controls it- a network's brains) from the data plane (the part where data traffic flows- a network's muscles) This means that with both network virtualization and SDN, network control can be programmed directly for applications and network services, without the need for manual configuration.

  • Both use a controller that runs specialized software to centralize network management.

  • Both (to varying degrees) fulfill the primary goal of increased agility by allowing administrators to quickly and precisely adjust the flow of data traffic across a network.

Over time, however, SDN has become more broadly-defined than network virtualization, meaning different things depending on who you speak to and how they are using SDN. The thread that links these different definitions is SDN's use of software to control networks and their physical devices. With SDN, software controls network switches and routers, but the network is not fully virtualized, as it is with network virtualization (components, configurations, functions, and all). Hardware often still plays a major role in an SDN network.

Virtual Networks in Physical Networks

Network virtualization allows you to look at your current physical network from a fresh perspective, one in which you're no longer restricted to the capabilities of your hardware. Software vastly extends your range of possibilities, recreating your hardware as a virtualized pool that can then be used as needed, on-demand.

Imagine your physical network doubled in scope: your physical network is there doing the job it's always done, but in parallel, with it you now have an identical virtual version running independently. alongside or on top of it. Once that virtual network has been created, it can be saved, closed, and restored later, possibly at another site. Or it can be deleted altogether.

Now imagine the scope of your physical network tripled, quadrupled, or more, Because virtualization separates networking from the underlying hardware, you can create as many virtual networks (copies of the physical network) as you need. Each of these virtual networks runs in splendid isolation, unaffected by events in other virtual networks or in the data center.


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