Why traditional network is replaced by software-Defined Network?

 Enterprise networks are vital in keeping your business connected but they're struggling to keep up with the demands of digital business more data video and voice more mobile users devices and cloud services and more online threats.  

A network is made up of lots of different boxes called routers and switches. Traditional network functions control how traffic is managed and forwarded it needs to be set up by hand which takes time is costly and is prone to human error and each piece of track isn't smart enough to know what the rest of the track looks like or how its performing adding more capacity or capabilities.  

Traffic means adding more of those routers and switches which means more time cost and complexity the Software-Defined Network (SDN) is different it works by virtualizing the network giving you new levels of visibility and control simply put it moves control of the network away from all the individual pieces to a centralized dashboard.   

You can build and adapt the perfect transport network in real-time. You get a real-time manually updating each piece of track. You can program it to adapt dynamically the rules you set helped your network become more intelligent and responsive. So, it can allocate bandwidth automatically making sure the most important traffic takes priority by pooling your network capacity. 

It can make efficient use of all hardware resources so that staff and customers get the best possible experience and because your network knows what's going on. It can detect and block security threats before they can derail your business. The SDN network works out for itself what each part needs to do saving time and cost. 

What is a Software-Defined Network? 

  

The industry and academia are discussing the principles adopted by the Industry Specification Group (ISG) to boost creativity in the utilization of network services, as well as support Capital Expenditure (CAPEX) and Operational Expenditure (OPEX). Many organizations and service providers are searching for more efficient approaches to increasing operational performance, decrease power consumption, and speed up their service implementations to resolve the above problems. In recent years, Network Function Virtualization (NFV) along with SDN has appeared as a successful approach.  Specifically, NFV and SDN are two closely related technologies that operate on various layers of the NFV architectural system using the network abstraction paradigm. NFV aims to virtualize all network capabilities from the hardware on which it resides, enabling the network to expand without adding more equipment. 

           SDN makes the configuration, programming, and operation of networks simpler. In other words, SDN is known to be extremely complementary to NFV, which is used to provide complete network control capability and handle traffic steering on the data plane as part of Service Function Chaining (SFC) development. SDN makes it easy to construct new networking abstractions, simplifying network management and enabling the network's transformation. 

Components of Software-Defined Network 

SDN was established by researchers who were dissatisfied with updating or modifying the software on network hardware equipment if they tried to try something different. SDN can be divided into three main layers/planes to develop the SDN architecture functionality. 

1. Application plane:  

The application plane requires separate SDN applications with different functions such as routing, load balancing, and security services. It links via the northbound interface with the SDN controller. 

2. Control layer: 

The Control layer makes choices on where traffic is sent. It consists of one SDN controller or more. It is responsible for maintaining a global view of the network logically, providing SDN applications with hardware abstraction, and performing control tasks to handle network devices in the infrastructure layer via southbound interfaces according to application requests. 

3. Data plane: 

Networking components such as virtual/physical switches and routers used to forward traffic flows based on rules installed by the controllers are comprised of the data plane. It allows the transition of data from/to the end hosts and handles conversations with the remote peers.