What is a Software-Defined Network (SDN)?

The Software-defined network or SDN is a different way of designing computer networks. For non-specialists, imagining an agile network architecture going through the micro-segmentation of the network may seem somewhat abrupt at first glance. If you're struggling to find the way out of the network maze defined by software and you find specialized literature hard to swallow, this article is for you. We simplify the concept of Software-Defined Network to make it understandable by all members of the company.


Base principle of a Software-Defined Network

The major problem when trying to understand the concept of Software-Defined Network is that the definition, like the concept, evolves. The driving force behind SDN is the desire to create a virtual control tower. This command post allows the network to be managed more efficiently and agilely. The goal is to free ourselves from static network architectures to define a fluid, adaptive and evolving architecture in order to best meet the needs of users.

Originally, SDN was the insertion of an additional network layer that would allow for more efficient communication between applications and network infrastructure. The control layer virtualizes the network elements to enable optimal and centralized management of the network infrastructure. Network optimization can  then be done in a variety of ways, for example by rationalizing  the paths used by the data to go from point A to point B or by ensuring a dynamic allocation of bandwidth.

In the absence of such an approach, the different network elements must be managed individually, which is counterproductive.

SDN simplified to the extreme

If we take the original concept of Software-Defined Network, it therefore results in the creation of an additional layer in the network, the Control Layer. Imagine a large golf course and its sprinkler system. The manager can manually open and close hundreds of valves  or can centralize watering management via a central table. With this central control panel, it is possible to plan which part of the land is watered at what time. Centralized management also makes it possible to adapt watering  according to weather conditions or sunshine and to make good use of the various wells dug in the field with a view to rationalizing resources.  The SDN is precisely that: the creation of a central  (in this case virtual)  table to manage the network.

In terms of computing, a "controller" is inserted between the Network Layer (i.e. hardware) and the Application Layer. This controller comes in the form of software. The connection between these different layers is achieved  through connectors that are called Southbound (to the network) or  Northbound  (to the applications).


Benefits of a Software-Defined Network configuration

We have already mentioned the benefits of the software-defined network. If you have followed, you may be wondering why this is not the norm. In the digital age, static networks seem anachronistic to say the least.

The benefits of a dynamic network configuration are many:

  • Optimizing network traffic;
  • Better bandwidth allocation;
  • Centralized and dynamic network management;
  • Reduced network operating costs;
  • Simplification in terms of network security and better detection of attacks. The network controller as such must, however, be extremely secure to avoid the risk of losing control;
  • Increased scalability is essential given the exponential growth of data.

In the future, networks are expected to become more complex at the same rate as  5G and the Internet of Things will unfold. Many organizations already need to ensure real-time interactions between different components including  servers, data centers and the cloud. These different elements handle an increasing amount of internal and external data to the network, so agility is essential. Software network management will therefore prove decisive in maintaining control over an increasingly complex architecture.

The segment is also expanding rapidly with an annual growth rate estimated by Technavio of about 24% by 2023. The International Data Corporation (IDC) is more optimistic, estimating this rate at 26.8%.   The size of the market is expected to increase from $8.82 billion in 2018 to $28.8 billion in 2023. The growth of SDN should also be driven by the generalization of multicloud in enterprises (i.e. the use of several cloud computing or storage services within the same network architecture). .

SDN, a step towards the intelligent network

Do you regret the time when creating a network was limited to choosing a router and you understood the language of your network manager? Don't worry, you won't have to worry about these considerations any more soon.  The software-defined network is indeed considered by many as a step towards creating a smart grid.  According to the IDC, we are on our way to an autonomous, intelligent network that can make decisions and adjust as needed. Thanks to machine learning and artificial intelligence, networks will have to be able to follow and implement a strategy defined by the network operator in a very short time. The creation of network management platforms or increasingly efficient network control software is an essential part of this evolution.

The complexity and the need to develop network intelligence will also lead to the consecration of Network-as-a-Service (NaaS) in the coming years. The network management will be outsourced and be passed on to specialized companies able to create and update the right software to increase the agility and flexibility of the network.

Ryax aims to create a state-of-the-art data engineering platform. We embrace innovations to offer ever-improving on-demand software. If you want to know more about  our solutions or meet our team, contact us today.

La Ryax Team.