What is SDN? Why SDN is the future of network?

SDN stands for Software Defined Network which is an approach to cloud computing. It refers to an network architecture that assists in making networks agile as well as more flexible. The main aim of the Software Defined Network (SDN) is to enhance the efficiency of the network and improve the network control. Thus we can say that it assists in facilitating the management of the network. This ultimately results in responding quickly to the changing business requirements by the enterprises and service providers. It suggests the new ways that define how to design, build and operate networks. To know more about Software Defined Network (SDN), it is important to understand the following two terms— the control plane and the data plane.

⏩ Control Plane

The control plane is one of the parts of the network and components of telecommunication architecture. It is mainly responsible for routing. Moreover, it makes decisions about how packets should flow throughout the network. It performs two basic functions-

System configuration


⏩ Data Plane

Data plane helps in moving packets from one place to another place. It is also is one of the parts of the network and components of telecommunication architecture.

How does SDN work?

Mainly, the SDN is based on the separation of the network control plane from the data plan. In other words, SDN helps in removing the control plane from network hardware.Further, it implements the control plane in software. Thus it enables programmatic access and makes network administration much more flexible. SDN works by separating the network’s control and then forwarding planes.

In the SDN, a packet reaches to the particular network switch. There are certain rules that give instructions to the switch to forward that packet. Further, the switch provides all the information about traffic to the controller. 

Further, SDN also gives a centralized view of all distributed networks. It, in turn, supports in enhancing the efficiency of orchestration and automation of network services. In this network, a network administrator or a network engineer can control the traffic without having touch any individual switches. Wherever the network services are needed, the centralized SDN provides support. It properly directs all the switches to deliver network services at the right place. No matter, whether there is a specific connection available or not between a server and devices.

Operation Mode of SDN

The operation mode of Software Defined Networking is also known as an adaptive and dynamic mode.In operation mode, the packet which does not have a specific route, SDN issues a route request to the controller.

What can SDN do?

Enable innovation for new applications, new services, and new business models.

It can reduce CapEx by allowing network functions to run on off-the-shelf hardware.

It can reduce OpEx by supporting automation and algorithm control. It, further, assist in making it simple to design, deploy, manage and scale networks.

Architecture of SDN

Let’s discuss about the architecture of SDN (Software Defined Network). Have a look at the following points-

The architecture of SDN comprises three types of layers. These layers are—– The Application Layer, The Control Layer, The Infrastructure Layer.

The application layer allows SDN to replace the appliance with the network application. These applications can be an intrusion detection system, firewalls or load balancing. To manage the behavior of the data plane, the application layer uses the controller.

The control layer is also referred to as the brain of SDN. It is the centralized part of SDN controller software. It supports in managing the policies and flow of traffic throughout the network.

The third layer is the infrastructure layer. It consists of all the physical switches in the network.

The communication among all the three layers of SDN flows with the help of Northbound and Southbound APIs. An API stands for Application Programming Interfaces.

The application layer communicates to the controller using northbound API while the controller, as well as switches, use southbound API to communicate with the application.

The SDN Data Path helps in exposing visibility and control over its data processing capabilities. It comprises of CDPI agent, traffic forwarding engines and traffic processing functions.

Features of SDN

Based on Open Standards- SDN is based on the open standards that assist in simplifying the network design and operations.

Configured Programmatically- It allows in configuring and managing and secure optimization of network resources.

Agile- It is agile in nature that allows network administrators to adjust traffic flow dynamically as per the changing needs.

Managed Centrally- Its centralized management capability enables in maintaining a global view of the network.

Programmable Directly- Since SDN is decoupled from forwarding functions, we can say that it is directly programmable.

Why SDN is the future of networks?

SDN (Software Defined Network) provides so many benefits to the user and due to its capability, superiority and effectiveness; this may be considered as the future of networks. SDN allows the administrator to change the defined rules for network switches as per their need. Moreover, he can prioritize, deprioritize or even block the specific type of packets. Furthermore, a network administrator or network engineer can manage the traffic loads efficiently in a flexible way. This ultimately assists in the cloud computing multi-tenant architecture. The SDN provides end-to-end visibility and efficient management control to the administrator.

A network administrator need not have to configure multiple individual devices, rather he can use one centralized controller. For the security reason, if any suspicious traffic is found, the controller can reroute the packets or drop the packets. Now the SDN is also capable of virtualizing the hardware and services of the particular hardware. This leads to reducing the operational cost of the organization.

Final Words: At last, we can conclude that SDN is emerging as the standard network which can be considered as the new way to describe abstracting network functions. It has its importance for all the enterprises as it simplifies the networking process for the data center as well as WAN deployments. Moreover, it assists in segregating network functions properly

Updated: June 6, 2019 — 1:23 pm

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