A BRIEF REVIEW ABOUT SOFTWARE DEFINED NETWORK (SDN)

Introduction

Software-defined networking (SDN) technology is an approach to network management that enables dynamic, programmatically efficient network configuration in order to improve network performance and monitoring making it more like cloud computing than traditional network management (Benzekki, K. et al, 2016)

The concept of SDN is not entirely new. As a matter of fact, a few decades ago people could use special infrastructure (such as cloud computing hardware) to decouple the network operating system (similar to the control functions in SDN control plane) from computing-intensive applications (similar to the data delivery in data plane). Today cloud computing enables the networked computation and storage without using local resources. Such a decoupling of control and data plays a critical role in large-scale, high-speed computing system.

Software Defined Network (SDN)

SDN results in improved network performance in terms of network management, control and data handling. SDN is a potential solution to the problems faced by conventional network and is gaining more acceptance in applications such as cloud computing. It can be used in data centers and workload optimized systems (Sherwood, R. 2010). By using SDN, the administrators have the ability to control the data flow as well as to alter the characteristics of the switching devices (or routing devices) in the network from a central location, with control application implemented as software module without the need of dealing with each device individually. This gives the network administrators the ability to arbitrarily change routing tables (routing paths) in network routing devices. It also allows an extra layer of control over the network data since the administrator can assign high/low priorities to certain data packets or allow/block certain packets flowing through the network.

Software-defined networking (SDN) is designed to make a network flexible and agile. SDN lets you design, build, and manage networks, separating the control and forwarding planes. As a result, the control plane is directly programmable, and it abstracts the underlying infrastructure for applications and network services.

Network intelligence is logically centralized through programmable SDN controllers. Implemented in software, these controllers maintain a coherent view of the network domain. To applications and policy engines, SDN looks like a single logical switch.

Software-defined networking (SDN) offers a centralized, programmable network that consists of an SDN controller, southbound APIs, and northbound APIs.

• SDN controllers are the brains of the network, offering a centralized view of the overall network.


• Southbound APIs relay information to the switches and routers in network.


• Northbound APIs communicate with the applications and deploy services.

Some Merits of Software Define Network

• Fast and automated application deployment.


• On-demand app delivery and mobility at scale.


• Greater resource flexibility and utilization.


• Reduction of IT costs by enhancing the benefits of data center virtualization.