What is Software-Defined Networking (SDN)

By | December 22, 2019
SDN Software Defined Networking

SDN has emerged as the next big thing in the networking industry. Is it another buzzword or is it the future of networking technology. Some companies such as Google have already started to use the SDN networking models, and have seen a performance increase from it. Over the past 2 years, there has been a tremendous rise in the number of companies that have shown interest in SDN.

But what is the need for SDN? What is it the SDN can offer but other networking models cannot offer? To understand this, we first need to understand what SDN really is or how does it work?

Lets’s have a look.

What is SDN and How do SDN works?

SDN Architecture

Let’s understand SDN in this way, today’s networks are made up of networking devices. For example- routers, switches, load balancers and more. These devices are extremely intelligent devices. You can say that they have their own little brains called the Control Plane. These Control Planes manages the whole network. IT makes sure that the devices are interacting with other devices, extract forwarding information from them, create databases, select the best path from the databases and push these best paths to the data plane (the body of the device). The Data Plane is where the actual traffic of the network flows.

Now since every device is intelligent, it has to be configured and managed individually. Now with hundreds of these devices in your network, managing them can be difficult. With the increase in the size of a network, it’s complexity increases and managing them individually on a per device basis could take a huge amount of time of yours.

Since your business nowadays is so fast-paced, you need to update the devices in your network time-to-time manually on each device.

So there has to be a better way to manage these large numbers of devices automatically. So this is where SDN comes into play.

It physically separates the control plane from the data plane of the device. It puts all the control planes onto a single controller from which you can manage all the devices. It creates forwarding tables and pushes them onto the data planes that are the devices.

Now the network engineer only has to deal with the controller now, not every device individually. And typically, there are graphical applications present that makes dealing with the controller more easier for the network engineer. The controller will let you automate a lot of stuff in the network.

So we can say that-

SDN, also known as Software Defined Network is a network architecture approach that enables the network to be intelligently and centrally controlled using software applications. This helps the operators to manage the entire network consistently. The goal of the SDN is to make the network more agile and flexible with respect to the changing business requirements of the market.

Benefits of SDN over a Network

sdn benefits

The way how SDN works differently from a normal networking model impacts the whole network a lot. It is a game-changer because of the way it enables programmable networks, centralizes intelligence and controls the network via APIs. Let’s explore the differences that SDN Brings to a network.

Reduced Network cost- SDN allows multi-tasking in the network. This requires fewer equipments as all the devices are controlled by the same controller. This doesn’t need the equipment of a large number of switches that are typically used in a traditional network.

Automation- Software Defined Network allows a level of automation that actually helps a network operator. It increases the speed of the overall network. Like in earlier days, when cloud computing was the big thing in the world market, many of the networks struggle to keep up with the excellent internet connectivity. But in SDN, you can alter the speed with tools specially made for cloud management.

Programmable Networks- This is the ability to control a network and its behavior using software that Software Defined Network provides to a network administrator. By differentiating the hardware and software of a network, a network administrator can innovate and add new features to a network immediately.

Centralize Intelligence and Control- SDN is built on a logically centralized network that enables an operator to intelligently control and manage the whole network. In a traditional network, devices function with limited awareness. But with centralized control that SDN provides over a network, the network operator gains a holistic view of a network.

Openness– SDN architecture takes the whole network to a net state of openness. The open APIs support a wide range of applications and cloud services using intelligent software that can control hardware from multiple vendors within a common software environment.

User Experience- SDN guarantees a higher quality of user experience. This enables a level of control and automation will ensure more certainty in overall content delivery.

Security- In many ways, an SDN offers better security to a company. The visibility helps the IT department spot any possible breaches easily. Apart from that, network operators who can access the controller can clarify secure routes in a system and block invalid routes.

Abstraction of Network- Applications and Services that are running on SDN are abstracted from the underlying technologies that provide connectivity from network control. Applications will interact with the network through APIs, instead of tightly coupled to the hardware.

We have told you every single possible benefit of Software Defined Network over a network but this doesn’t mean that there are no drawbacks in an SDN network. There are few disadvantages of SDN and those disadvantages are mentioned below-

Cons of SDN over a Network

Improvements- SDN is a kind of new technology and being a new technology, there can be some key improvements in different fields.

Lack of Hardware Security- One of the key disadvantages of an SDN network is that since you are eliminating the use of physical routers and switches, you won’t have security that comes with them. The main thing that you will be missing is the firewall. This can leave your network more vulnerable.

Where SDN is used?

SDN has a large number of benefits as compared to a traditional networking model, that’s why it is used in various fields in the software and the networking industry. And some of its use cases are mentioned below-

In-Service Provider Networks- Software Defined Network simply helps service providers to simplify and automate the provisioning of their networks by offering end-to-end and service management control.

DevOps– SDN can facilitate DevOps by automating the process of app updates and deployments.

Data Centers- SDN is a very important technology when it comes to data centers. SDN supports targeted protection and enhances the firewall. This extra layer of firewall security helps prevent a breach in the virtual network in a data center. Also, it centralizes the control and automation allows the admin to view, control and modify the network activities as well.

Campus Networks– Campus networks can be difficult to manage, especially with the ongoing need to unify Wi-Fi and Ethernet networks. SDN controllers can benefit can help the campus networks by offering centralized management and improving the delivery quality of content all over the network.

So SDN is receiving a lot of attention lately. And it’s not only from the customers but also from the vendors as well. Many vendors are conducting industrial events to create awareness about the Software Defined Network and its benefits. And many think that SDN is the next big thing in the networking industry.

But what are you thought’s on SDN? Do you think that Software Defined Network will be the next big thing? Do tell us in the comments section below.

Watch What is Software-Defined Networking

Video by IDG TECHtalk

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