
Software-Defined networking: Types

Software-defined networks offer one way of meeting these demands by shifting networking control away from traditional hardware onto commodity server hardware, supporting increased traffic levels while improving performance and decreasing costs.
There are various SDN architectures, each differing in implementation details, controller structures and management interfaces.
Open SDN A open SDN architecture controls virtual and physical devices to route data packets by using open protocols.
- SDN API: The topology is based on the Southbound APIs and controls data flow from and to each device.
- Overlay SDN model: The SDN creates a virtual network over the existing hardware and offers tunnels to data centers. The model assigns devices to channels and distributes bandwidth within each channel.
- Hybrid Model SDN: The hybrid model combines the best features from SDN and traditional networking. This topology allows the best protocol to be allocated for each type of traffic. Hybrid SDN is often used as a way to introduce SDN in a gradual manner.
SDN Architecture
Software-defined networking (SDN) comprises three primary layers; application layer, control layer and infrastructure layer.
All three may or may not exist physically together.
Application Layer
This layer contains network functions or applications used by businesses to improve application speed, streamline IT infrastructure and increase security.
Examples include intrusion detection systems (IDS), WAN Optimization Controllers (WOC), Load Balancing Systems and Application Firewalls.
Traditional networks rely on specific equipment for these tasks; software-defined networks (SDN) utilize applications which manage data plane behavior through controllers; these controllers receive network instructions from programs on the application layer.
Control Layer
Control Layer is responsible for network policies and traffic flow management. Incorporates requirements from applications to network infrastructure before returning data back from network back into application to increase functionality.
SDN controller software serves as part of the control layer. The SDN controller offers network teams centralized visibility and allows for efficient traffic forwarding through forwarding layers within their infrastructures.
Administrators of a network must also enforce regulations that govern activities within it, setting policies uniformly across nodes that outline levels of access, resources available for network traffic and priorities for priority traffic.
Infrastructure Layer
Infrastructure Layer Devices In the infrastructure layer lie the network switches and routers which perform vital data processing and forwarding functions while also collecting important metrics about network usage and topology to report back to the control layer.
Why Does Business Need Software Defined Networking?

Recent years have witnessed dramatic shifts in network traffic patterns for organizations as more systems move to the cloud and demand increases for mobile-friendly applications.
While conventional network topologies were sufficient when applications operated using client/server models, they no longer offer adequate coverage.
Self-service tools allow users to quickly adapt to service changes. Data center applications rely heavily on network performance; many application teams now wish for greater control of application delivery while IT teams aim to reduce complexity and costs related to infrastructure management.
businesses require technology that guarantees operations remain operationally flexible and scalable in order to support growth.
Software-defined networks offer seamless network control and operational efficiencies; additionally they accelerate business results.
SDN allows business networks to be dynamically reconfigured on demand and adapt transparently to service changes by consolidating all functions into one control plane.
Switches and routers can then be programmed directly by IT teams allowing full control over how network resources are utilized resulting in improved end user experiences.
Businesses can more efficiently allocate network resources by making use of software-defined networking (SDN). SDN enables software applications to program networks using open APIs.
This makes the network flexible and manageable while remaining adaptable for future uses.
Software-defined networks (SDN) offer another means to increase network security: categorizing business traffic into different networks.
Certain networks could be dedicated exclusively to transporting sensitive data while others might remain public - thus restricting hackers who gain entry via public-facing web servers from reaching any protected areas, like data centers.
Why Is Software-Defined Networking Important?

SDN represents an evolution over traditional networking in terms of its capabilities:
- Greater control and flexibility at higher speeds: Developers can now more quickly control network traffic flow by programming an open-standard software controller. Administrators now also enjoy more choice when selecting networking equipment since a central controller communicates with multiple hardware devices through one protocol.
- Customizable Network Infrastructure: Software-defined networking enables administrators to quickly configure services and allocate virtual resources that alter network infrastructure in real-time from a central location, in real-time. Network administrators can optimize data flow through the network while prioritizing applications requiring greater availability.
- Robust Security: Software-defined networks offer unprecedented network visibility and an overall view of threats to protect from. SDN stands out against traditional networking due to the proliferation of connected smart devices; SDN enables operators to easily create zones dedicated for devices of various security levels or quarantine compromised devices immediately so as not to infiltrate other parts of their network.
SDN infrastructure differs from traditional networking in that its control plane resides entirely within software; by contrast, traditional networking relies on physical elements for its control plane.
SDN offers greater flexibility compared to hardware-based networks as its control plane operates through software instead. Administrators are able to easily manage networks from a central user interface using SDN while changing configuration settings, allocating resources, or increasing network capacity as required.
SDN boasts several distinct security benefits compared to traditional networking, making it more secure in many ways due to increased visibility and secure pathway definition.
Software-defined networks rely on one central controller; as such, its security must also remain paramount if we wish for our networks to remain safe.
How Does Software-Defined Networking Work?

SDN (software-defined networking) is the virtualization of hardware and software into one solution, moving control plane decisions (such as how traffic should flow) over from hardware to software -- enabling administrators to control and program an entire network in a consolidated fashion from a central window rather than device by device.
Three components of an SDN are typically spread throughout its network.
- Applications (or apps) are programs which share information or resource requests across a network.
- Controllers use information provided by applications to them in order to select an optimal path for data packets to follow.
- Networked Devices that receive information regarding data from its controller.
- Virtual or physical networking devices serve to transport data across a network. Virtual switches may be embedded within either software or hardware to replicate physical switching functions; once verified as genuine packets arrive at their virtual machine destination theyre passed along for transport to be processed further along.
How To Implement Software-Defined Networking?

Software defined networking should only ever be implemented without first devising an actionable plan and strategy for doing so.
These tips will assist in managing your network more effectively:
Establish a Use Case - Make sure there is an issue for SDN to solve and focus your initial efforts there, before expanding further with other use cases or full implementation of SDN.
Doing this allows for measurement and learning which will assist further implementations of this technology.
Establish an Inter-Functional Team - Implement SDN in teams made up of diversely skilled individuals to maximize its success and achieve optimal implementation results.
Collaboration must play an integral role.
Start small - Before changing an entire network, initiate SDN implementation on an unimportant segment first.
Review- Evaluate data to ascertain that test results satisfy your goals, before rolling out SDN across your network.
Be certain it provides solutions to specific problems.
Benefits Of SDN

SDN technology presents numerous advantages over more conventional network architectures.
- Control of the Network: SDN centralized network control into one controller, making it simpler and faster to configure and manage networks. Furthermore, administrators can set and enforce policies more precisely on these networks for improved network security, reliability, and performance.
- Network Programmability: SDN environments enable network devices to be programmed and reconfigured as necessary, giving administrators more agility in adapting quickly to changes in traffic patterns for improved network performance.
- Cost savings: SDN allows network administrators to utilize inexpensive commodity hardware instead of proprietary solutions when building networks, significantly cutting the costs involved with proprietary solutions and manual management - saving on labor and maintenance.
- Improved Network Security: With SDN networks central control comes easier security threat detection and response capabilities for administrators. Furthermore, rules and policies enable more fine-grained implementation of security controls by administrators.
Scalability An SDN allows for easier network scalability in response to changing traffic needs, with administrators easily being able to adjust capacity according to programmatic control. - Network Management Simplified: SDN makes network administration simpler for administrators by abstracting network hardware into one logical network view, making troubleshooting and management of the network simpler - leading to improved uptime and reliability for networks.
SDN is a flexible, programmable and centralized networking approach that can lead to significant cost savings and enhanced network security.
It also improves network performance and reliability.
Read More: All You Need To Know About Cloud Computing
SDN: Its Advantages And Disadvantages

Software-defined networking has many advantages over conventional networks, yet some drawbacks must also be considered.
Below are the major cons associated with SDN:
- Complexity: Software Defined Networks are more difficult than conventional networks due to requiring advanced technologies and more specialized management skills; for instance, using a central controller as part of its network management requires knowledge about SDN architecture and protocol.
- Dependency on the Controller: Should an organizations controller go down, this could spell disaster for its entire network and should therefore ensure availability with an effective backup and disaster recovery strategy in place.
Compatibility Issues When upgrading or replacing legacy network devices in order to fully utilize SDN, organizations may need to upgrade or replace them so as to benefit fully. - Security: SDN can increase network security but also introduce additional risks. A central point of control could become an easy target for attackers while its programming capabilities could make manipulating traffic easier for malicious actors.
- Vendor Lock-In: SDN solutions from different vendors may not interoperate properly and lead to vendor lock-in, restricting organizations ability to change vendors or adopt new technologies into their network. This may prevent organizations from being as agile in adapting new solutions from entering their networks quickly enough.
- Network Performance: Control of an SDN network through centralized control can create latency issues which in certain circumstances could compromise network performance, impacting its functionality as a network grows in size and sophistication. Furthermore, its overhead could potentially diminish performance as its network grows larger in scale.
- SDN technology offers many benefits to organizations; however, their implementation should only be undertaken after carefully considering any possible drawbacks that might accompany it.
To make an informed decision and understand any limitations related to SDN implementation. Its crucial that organizations conduct a detailed assessment of both their current infrastructure and needs and its advantages or drawbacks when considering whether SDN solutions should be adopted by an enterprise.
What Is The Difference Between SDN And Traditional Networking?

SDN infrastructure stands apart from traditional networking in that its control plane runs entirely through software instead of being hardware based, offering greater flexibility than hardware-based networks and allowing administrators to easily manage networks from a central user interface - managing configuration settings, allocating resources and increasing network capacity as necessary.
SDN boasts distinct security advantages over traditional networking, providing greater visibility and the definition of secure pathways.
Furthermore, using a central controller that protects its network security is vitally important.
Traditional Networking: What Is It?

Understanding SDN requires having an introductory knowledge of infrastructure networks. A conventional network consists of end-to-end links where all computers can directly exchange messages between each other.
To better comprehend SDN functions requires learning how to deploy it over infrastructure networks in general.
Computers can utilize various technologies such as wireless urban networks, local area networks, wide area networks and satellites to form connections among themselves.
Hardware and software together comprise traditional network infrastructures. This combination provides for computation and communication among users, services, and applications; at its foundation lies fixed-function network hardware such as routers and switches which each serve a specific function in maintaining their networks.
Networks are typically depicted with an intuitive two-dimensional map of nodes connected by lines; however, this does not accurately portray reality: data plane, control plane and management plane represent three "dimensions" or planes within any network which act as representations for its operations that take place.
Data Plane
The data plane, commonly referred to as forwarding plan, is an infrastructure layer in a network which serves to carry network traffic.
Usually this functionality can be found embedded into devices firmware;
Control plane actions establish the data plane. Data plane traffic must be carefully managed in order to protect routers and networks against different attacks; accordingly, its security strategy should take account both legitimate and malicious traffic flows.
Control Plane
The control plane of any network layer is responsible for routing and signaling. Being independent, its main task is communicating between network elements via protocol communication between components such as routing protocols, signaling protocols, link state protocols and additional control protocols to build network services.
Management Plane
Management planes form part of any control plan and serve both administrative traffic as well as device administration.
Theyre essential in keeping routers and networks functioning optimally - compromised management planes will allow unauthorized access, leading to attacks against IP traffic planes via adding new routes or altering flow rates. It is equally crucial that management planes be properly secured. A compromised management plane always leads to unauthorized entry; once compromised an attacker may also try to access IP traffic planes by adding routes or changing flow.
Switching and routing in computer networks are performed using hardware components with three-plane configuration, but recent trends are toward software devices which run on general purpose central processing units (CPUs).
Use Cases Of SDN

SDN can be used in the following ways:
- DevOps.SDN facilitates DevOps through automating application updates and deployments; it may even involve automating IT components while DevOps platforms and apps are deployed.
- Campus Networks.Managing campus networks can be complex when managing Wi-Fi and Ethernet together, but SDN controllers provide essential centralized management, automation and improved security features that make campus management much simpler.
- Service Provider Networks SDN can simplify and automate provisioning and management of networks and services for service providers.
- Data Center Security. SDN simplifies firewall management while offering more targeted protection for enterprises data centers. While enterprises typically rely on perimeter firewalls to keep out threats to their data, software development companies can create a distributed system of firewalls by adding virtual ones protecting virtual machines - adding this extra layer can prevent breaches on one virtual machine from spreading to others and allows admins to monitor, modify, and control their network with SDN central control & automation in order to minimize risk exposure.
SDN
Software-defined networks have had an immense effect on IT infrastructure management and network design. SDN technology continues to develop, altering not only network infrastructures but also the roles played by IT in society at large.
SDN architectures make network control programmable through open protocols like OpenFlow. This enables enterprises to apply software control at the edge of their networks instead of depending on proprietary and closed firmware for managing resources, optimizing, and protecting networks.
SDN technology can be found across industries, but its greatest impact can be seen in financial and technology environments.
SDN has made an immense difference to how telecom firms operate, particularly Verizon who employ it to combine existing routers that provide Ethernet and IP services into one streamlined platform in order to increase operational efficiencies as well as flexibility for new services and functions.
SDN financial services success relies upon its ability to connect to multiple trading participants simultaneously while offering low latency, secure network infrastructure and efficient ways of running global markets.
Nearly all participants in financial markets rely on legacy networks which can be unpredictable and hard to manage, slow to deliver services, vulnerable to attacks, and hard to maintain.
Financial services organizations can leverage SDN technology to construct predictive networks which will create more effective and efficient platforms for trading apps.
SDN And SD WAN
SD-WAN technology is an efficient means of routing network traffic over wide area networks (WANs) using SDN concepts, providing more direct routes between datacenters and branch offices.
SDN and SD-WAN share many similarities; both services offer virtualized network functions while segregating their respective data plane from control plane.
SD-WAN technology works differently by connecting geographically dispersed offices within an organization using software applications directed towards its WAN network.
Following are additional differences between SDN & SD-WAN:
- SD-WAN can be programmed by its provider; however, customers can also program SDN.
- SDN is accomplished via network function virtualization (NFV), taking place within an enclosed system. SD-WAN appliances serve to route applications over virtualized WAN connections.
- SD-WAN (Software Defined Wide Area Network) is an Internet routing system built around apps running over consumer broadband Internet that delivers superior performance at lower per megabyte costs than its Multiprotocol Label Switching counterpart.
SDN and SD WAN technologies serve different goals; small to midsize businesses often rely on SDN for central locations while larger organizations needing off-premises connectivity often turn to SD-WAN.
Software-Defined Networking Companies

Cisco, Arista Networks Juniper Networks and VMware all provide software-defined networking.
Cisco
Cisco ACI solution aims to automate policy automation and management across physical and virtual environments from within one single system, offering consistency for policy administration across multi-cloud architectures where data or applications may reside.
ACI targets data center segments while creating multi-cloud solutions which maintain consistency of policy enforcement regardless of data location or application location.
Arista Networks
Arista Networks Extensible Operating System is a network operating system composed of Ethernet switches and routers built using commercial silicon technology for large data centers or campus workspaces.
Juniper
Juniper Networking Solutions Contrail Networking Solution is an open-source platform built around SDN standards.
Customers using it can securely deploy workloads anywhere while enjoying continuous overlay connectivity for any workload that runs across traditional servers, virtual machines and containers.
VMware
VMwares NSX virtualization platform abstracts physical networks in order to simplify provisioning, consumption and administration of networking and security services.
Layered in any environment for maximum flexibility, NSX integrates easily with automation solutions as well as security or container solutions for seamless service provisioning and consumption management.
Conclusion
In conclusion, utilizing software-defined networking (SDN) technologies can bring numerous benefits to organizations that manage complex networks.
SDN provides a centralized, programmable approach to network management that allows for increased flexibility, efficiency, and scalability.
With SDN, network administrators can easily manage and configure network devices, applications, and traffic flows from a centralized control plane.
This simplifies the management of complex networks, reduces the risk of configuration errors, and improves network resiliency and availability.
Moreover, SDN enables organizations to quickly adapt to changing business needs by providing dynamic and agile network provisioning.
Network resources can be easily scaled up or down to accommodate changes in traffic demand or application requirements.
In addition, SDN enables organizations to improve security by providing a more granular control over network traffic.
Policy-based management allows for network segmentation and access control, which can help prevent unauthorized access and reduce the risk of security breaches.
Furthermore, SDN can reduce operational costs by automating network provisioning and management. This leads to quicker issue resolution, reduced downtime, and increased employee productivity.
Overall, by utilizing SDN technologies, organizations can achieve better network performance, flexibility, security, and cost efficiency.
As network infrastructures continue to grow in complexity and scale, SDN can provide a strategic advantage for organizations seeking to optimize their network management processes.