The massive expansion of multimedia content, the boom of cloud computing, and rising mobile usage are destroying typical business models and ongoing commercial pressures to cut costs as profits remain stagnant.
Most businesses are now using software-defined networking (SDN) technology to reinvent network layouts and operations to keep up. Let’s examine SDN technology to see what it is, how it works, and why you should use it for all your networking requirements in the workplace.
What is Software-Defined Networking (SDN)?
A group of technologies known as “software-defined networking” (SDN) enables network management through software. Thanks to SDN technology, IT managers can use a software program to customize their networks.
SDN software is open; therefore, it ought to be able to function with either switch or router, regardless of the manufacturer. This model differs from conventional networks, which employ specialized hardware components to manage network traffic. SDN can build and manage virtual networks or conventional hardware through software.
While SDN offers a new method of managing the redirection of data packets through a centralized server, network virtualization enables businesses to portion different virtual networks inside a solitary physical network or to connect devices on distinct physical networks to form one virtual network.
A network operator can manage traffic in an SDN from a single controller console without altering any individual switches. Irrespective of the precise links between a server and devices, a centralized SDN controller instructs the switches to provide network services anywhere they are required.
What does the SDN Architecture look like?
Three layers make up a basic SDN architecture. They are the infrastructure layer, control layer, and application layer. These layers interact using northbound and southbound APIs.
Infrastructure Layer
The actual network switches make up the infrastructure layer. The network traffic is forwarded to its destinations by these switches.
Control Layer
The SDN’s control layer consists of the SDN controller software. This controller, which is housed on a server, controls network-wide policies and traffic patterns. SDN is practically made possible by dividing the control plane and data plane. An abstract idea of the location where networking activities occur is referred to as a “plane.”
The data plane is the real information moving via the network, whereas the control plane relates to networking operations that govern network traffic. The control plane accomplishes this by defining network paths and which protocols should be utilized.
Consider the control plane to be like the collection of stoplights that are present at city junctions. Each router or switch must be configured separately in networking installations that only employ physical hardware.
The data plane, the underlying network infrastructure, and the control plane are linked heavily. The control plane may be configured from a central place thanks to SDN, which separates it from the data plane and the equipment.
Application Layer
The normal network applications or features businesses use are found at the application layer. This may involve firewalls, task scheduling, or systems that detect intrusions. A software-defined network substitutes an application that utilizes a controller to regulate data plane behavior, whereas a typical network would employ specialized equipment, such as firewalls or load balancers.
Datapath SDN
A logical network component called the SDN Datapath provides transparency and unchallenged control over its claimed data handling and forwarding abilities. A Control to Data-Plane Interface (CDPI) agent, a collection of traffic forwarding engines, and a collection of traffic processing functions make up an SDN Datapath.
Simple forwarding between the datapath’s exterior interfaces and internal traffic handling or termination functions are examples of these engines and functions. A single network node may include only one SDN Datapath or many. It is also possible to define an SDN Datapath spanning numerous physical network components.
How does Software Defined Networking Work?
With SDN, network administrators may preprogram and manage the entire network from a single location rather than by each device.
SDN is made up of three parts:
- Applications that convey actions, requests for resources, or network-wide data.
- Controllers gather data from applications and hardware and properly route it.
- Networking hardware that processes and moves data as instructed after receiving it from the controller.
The SDN controller integrates all of these three elements, or levels. The northbound interface refers to the connection between the controller and the application, whereas the southbound interface refers to the connection that links the controller and networking devices. In addition to these elements, OpenFlow is a customizable connection-oriented protocol used throughout SDN that manages traffic between network devices.
The OpenFlow protocol and other open-source SDN solutions were allowed to become standards by the Open Networking Foundation. To maintain an adequate network flow of traffic, these elements comprise SDN ecosystems.
SDN includes a number of technological categories, such as functional separation, network virtualization, and automation via programmability.
The initial objective of SDN technology was primarily the division of the network control plane and data plane. The data plane transports packets from one location to the next until the control plane decides how they should proceed through the network.
An arriving packet finds its way to a network switch in a typical SDN environment. The switch’s unique firmware has rules that direct it where to send the packet. The switch receives these packet-handling instructions from the centralized controller.
When necessary, the switch asks the controller for instructions and gives the controller data about the bandwidth it manages. Every packet heading towards the same destination is sent along the same path by the switch, and then every packet is handled equally.
A switch sends a request to a controller for one packet that lacks a specific route in software-defined networking’s so-called adaptive or dynamic operating mode. Adaptive routing, which does not use a controller and instead provides route requests via devices and algorithms, is distinct from this method.
SDN’s Use of Virtualization
Sometimes, the terms “Virtual Network” and “SDN” are used interchangeably. Despite being different from one another, these two ideas complement one another wonderfully.
Network Functions Virtualization (NFV) divides a physical network into one or more logical networks. Through NFV, devices on several networks can be linked to form a single virtual network, which frequently includes virtual machines.
NFV and SDN function well together. It helps by boosting transparency and control by streamlining the process of managing data packet routing through a centralized server.
Types of SDN
SDN is divided into four main categories, each of which has its own advantages:
- Open SDN: Open SDN employs open protocols to manage the physical and virtual devices that direct data packets.
- API SDN: These manage data of every device through programming interfaces, also known as southbound APIs.
- Overlay Model SDN: It builds a virtual network on top of already installed hardware and offers tunnels with channels leading to data centers. Following that, each channel’s bandwidth is allotted, and devices are assigned to every channel.
- SDN Hybrid Models: These models enable the best protocol to be allocated for every form of traffic by fusing SDN and conventional networking.
Benefits of Software-Defined Networking
SDN has a lot of advantages that not only enhance the position and day-to-day duties of Information Technology (IT) service providers but also accelerate and streamline network management to support more agile business operations. Some of the key advantages of SDN include:
More Visible and Programmable Networks
Visibility significantly increases whenever there is a centralized location from which to obtain and handle data. This is the situation with SDN’s centralization, which eliminates some of the blind spots that have historically troubled traditional networks by making it simple to get a network overview in one location.
SDN makes it possible for software residing outside the network equipment to regulate network behavior. As a result, network administrators can modify the actions of their networks to accommodate brand-new services and even specific clients. Operators are independent of the limitations of closed and private platforms by separating the hardware from the software, allowing them to quickly introduce creative, distinctive new services.
Higher Efficiency IT
SDN transforms the job of IT teams by streamlining and simplifying network administration, allowing them to concentrate more on enhancing service delivery and less on managing the network. The ultimate user experience is considerably improved with better service.
Centralized Command and Information Logically
Logically centralized network topologies, on which SDN is based, allow for the smart coordination and monitoring of network resources. Distributed network control techniques are common. With little knowledge of the network state, devices operate autonomously.
A network’s throughput management, recovery, safety, and policies can all be highly intelligently managed and optimized with the kind of centralized control an SDN-based network offers. Additionally, an organization gains a comprehensive understanding of the network.
Swift Speeds
SDN enables swift network-wide movement of workloads. For instance, by segmenting a virtual network, telecom companies can relocate customer services towards less costly servers or even the client’s own servers.
When it is necessary, service providers can move tasks from personal to public cloud services and infrastructure and quickly launch new customer services using virtual network infrastructure. SDN makes it simpler for any network to bend and scale as network managers add or remove them.
Scalability
Expanding business operations is made considerably simpler by SDN’s agility since more devices that enable business growth can be included in the network as required without running the risk of a service outage.
Favorable to Big Data
Organizations need a significant amount of bandwidth to handle the information as they cope with ever-growing data collections. SDN offers an efficient approach to meet today’s enormous data needs by analyzing large datasets concurrently, controlling the amount of data transported to multiple destinations, and assuring dependable connectivity.
Innovations in Networking
SDN enabled the development of Software-Defined Wide Area Network (SD-WAN) technologies. The dynamic overlay feature of SDN technology is used by SD-WAN. With SD-WAN, a firm’s WAN connectivity lines are abstracted, resulting in a virtual network that may send data via whatever link the controller deems appropriate.
Increased Safety
Another significant benefit of SDN in terms of security is its centralization. Network administrators can create and spread vital security rules and protocols across the whole network, ensuring that all devices and other significant components are covered.
Open Source
Organizations don’t have to subscribe to any single vendor’s network products because open source SDN uses open standards and may be utilized with any vendor’s network gear. As a result of the SDN’s ability to connect to numerous clouds, hardware, and software, the organization’s IT is more agile.
DevOps
By automating application upgrades and deployments, SDN can support DevOps. As the DevOps applications and platforms are implemented, this technique may involve controlling IT infrastructure.
Cost-effective
SDN involves fewer administrative costs and increases server usage, which results in a more economical overall ownership cost and lower operating costs. Commodity devices can also replace conventional switches to reduce expenses further.
Disadvantages of Software-Defined Networking
As we’ve seen, SDN may help an organization in a variety of ways, including enhancing governance and agility, streamlining management, and enhancing security. However, it does have some disadvantages and challenges to overcome. Let’s look at some of them:
Single Failure Point
A safe network must be maintained by the controller. If the SDN controller becomes unavailable due to a hardware or software failure or if it is compromised by an attacker, the entire network can be affected.
However, this weakness can be mitigated by implementing redundancy and failover mechanisms. For example, multiple SDN controllers can be deployed in a high-availability configuration, where one controller acts as the primary and the others act as backup. If the primary controller becomes unavailable, the backups can take over the network control and continue to forward traffic.
Security
With SDN, threats can spread across the network just as quickly as security rules can. This is one manner where SDN’s centralization can lead to a vulnerability, particularly at the controller level. Network administrators, however, can identify the weakness and help guarantee the controller’s security by being conscious of this element of SDN.
Upfront Expenses.
Even though SDN has a reduced overall cost, moving to and implementing SDN might come at a hefty upfront cost due to the resources and time necessary for production and planning trials, procurements, new or modified software licensing, and IT education.
Market Turbulence
White box networking, network automation, and network disaggregation are other networking efforts frequently confused with SDN. SDN remains a distinct technology even if it can profit from and collaborate with these systems and procedures.
Compatibility
SDN requires hardware compatible with OpenFlow or other similar protocols, which may not be available or supported by all vendors.
Standards
The SDN industry is still in a state of flux, with different vendors offering their own proprietary implementations. This lack of standardization makes deploying and managing multi-vendor SDN environments challenging.
Performance
SDN can have an impact on network performance depending on the design and implementation. In a traditional network, switches, and routers are responsible for forwarding packets based on predefined rules and configurations. In an SDN environment, forwarding decisions are centralized in the SDN controller, which uses software to configure switches based on network traffic and policies.
This centralized control can introduce additional latency as packets are first sent to the controller for processing before being forwarded to their destination. This additional delay can be more significant in larger networks with many devices and a high volume of traffic. However, this latency can be reduced by ensuring that the controller is located close to the network devices and by using high-performance hardware and software for the controller.
Use Cases of Software-Defined Networking
SDN was employed at Tribune Media, which used VMware NSX to shift over 140 apps to the company’s new SDN infrastructure. By dispersing network tasks, such as routers, switches, and firewalls, throughout the environment, VMware’s virtual networking and protection software allowed essential business and data processes to run as efficiently as possible without compromising security or dependability.
Final Thoughts
SDN is growing in popularity every year. Some network engineers worry that programmers with in-depth knowledge of C/C++, Java, or Python will take their jobs because they have personally witnessed stories about how the entire infrastructure will be programmed in the long term.
The ability for network administrators to create programs that make use of SDN APIs and give apps access to network behavior is a significant benefit of SDN technology. Users can create network-aware applications, monitor network health smartly, and instantly switch the network configuration as needed, thanks to SDN.
