Detailed Look into the Software-Defined Networking (SDN)
Detailed Look into the Software-Defined Networking (SDN)
The primary aim of SDN technology is to enable a centrally controlled network through software applications.
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Hardware control in the networking world was relevant to the year 2008 timeframe. It is when the first emergence of software-defined networking (SDN) become noticeable with the OpenFlow protocol. Then it used to be regarded as a technology that falls in the category of distinguished network control mechanism which streamlined automation and policy-based organization of the network resources.
Since the first appearance in the form of OpenFlow, SDN has progressed to become one of the most sound and reliable networking technology that is offered by a lot of technical service providers such as, Cisco.
What Is Software-Defined Networking?
Software-defined networking (SDN) in all simplicity is an architecture that facilitates networking agility and flexibility. The primary aim of SDN technology is to enable a centrally controlled network through software applications. The purpose behind software-defined networking is to assist ever-changing business requirements through intelligently programmed services in order to help organizations manage their entire network consistently and comprehensively.
With the help of software applications based on application programming interfaces APIs, SDN allows network programming in a centrally controlled environment. That enables organizations to open up previously concealed network platform through common SDN control implementation and manage their whole networks without technological complexities.
Due to the massive induction and influence of the varying nature of the content, increasing cloud computing dependency, growing mobile and another device usage, coupled with several consumer supplier dynamics and permanent business pressures all has converged to absolutely alter the traditional business modus operandi. In an attempt to achieve a semblance of control, businesses today, are actively seeking technical assistance to improve their operations and operational performance alike.
Network design is pivotal to this digitalization of business models which turns SDN technology equally critical by association. The SDN enterprises or general IT service providers are coming up with one revolutionary solution after another to keep pace with exceedingly close competition within.
The popularity of Cisco SDN is largely due to the controller based centralized and programmable network application for they provide the consolidated view of the organization’s overall network. SDNs are also transforming the existing architecture of data centers along with the connected networking models to make organizational networks auto-adjust to the requirement of the application.
What Is SDN Controller?
SDN controller is regarded as the brain of the network by Cisco, it is basically a software that brings forward the centralized view as well as total control over the organization’s entire network. The IT operators, managers, or network administrators within/out of the organization manage the forwarding plane of essential infrastructure to regulate traffic through the controller. It is a policy-based manager of the organization’s network resources and overall behavior. The Network administrators device policies and apply them consistently to the manifold nodes within the network.
These policies are in essence a set of rules directed at the inflow of network traffic to decide the access level to the said network, permissible resources, and assigned priority. To maintain all of it through a centralized view of the network based on preset policies allows simple and uniform network management.
The Architecture of Software Defined Networking
SDN architecture is configured with the three-layer assistance that includes:
The applications include a number of services that run on the network while the control administers through the SDN controller that is regarded as the brain of the network and the infrastructure is comprised of networking switches and routers along with the support hardware. In order to function these layers need to communicate with each other. To facilitate this interaction SDNs have individual application program interfaces called:
- Southbound APIs
- Northbound APIs
The northbound APIs are meant to communicate between the control layer and the infrastructure layer whereas southbound APIs are intended to communicate between the control layer and application layer.
What Are Northbound APIs?
In order to the available resources, SDN applications are dependent on the controller to determine the network infrastructure status. The application traffic requires the SDN controller to be routed in absolute coordination with the pre-established network policies by administrators. These intricacies are well explained in the Cisco called Software-Defined Networking (SDN) and Network Function Virtualization
The application layer actively communicates with the control layer and inform it about resource requirement and location. The control layer then organizes the resource order and its delivery as per the availability in the network. The control layer utilizes the intelligence to invent the ideal application path with synchronized latency and security. This organization process of northbound APIs is not manually configured, instead, it is preprogrammed to be automated.
What Are Southbound APIs?
In southbound APIs, the SDN controller (control layer) communicates with the infrastructure layer of the network through routers and switches. The network infrastructure is instructed to follow the application data path that was set by the controller. Although, the controller is powered to improvise the way routers and switches use to move the data, but the network infrastructure data is not dependent on physical devices or routing lanes to decide where to go. For the intelligence, that controller possesses serve to make optimal decisions and adjust the path for data movement.
Benefits of SDN
Besides providing a centralized view of the programmable network that offers consistent network resource provision to keep up with the ever-changing business requirement, SDN provides the number of technical as well as business benefits that include:
Centralized Management and Programmability
The SDN control functions and forwarding functions are decoupled that enable programmatic configuration of the network through automation tools that are open source or through proprietary. The intelligence of the network is centralized in the controller (brain) software that provides a centralized view of the network as a single switch.
SDN is automated for the most part of its applications that also includes network software updates. Which minimized the opex by eliminating the need to replace network infrastructure with every business or network requirement. Another aspect that reduces the margin for human error is the uniform and network-wide spread of policies. This automation covers network administrators or operators’ tasks to significantly minimize the time of network management.
Agility and Flexibility
SDN is meant to provide increased agility and flexibility to help businesses deploy the latest applications and services in the existing infrastructure to meet business objectives heads on. With every new modification and creation, a simple update integrates it throughout the network.
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