Several competing forces surround enterprises, carriers, and service providers. Massive growth in multimedia content, the explosion of Cloud computing, the impact of increasing mobile usage in the Internet of Things era, and ongoing business pressures to reduce costs while revenues remain flat are all wreaking havoc on traditional business models. Many of these players are turning to Software-Defined Networking (SDN) technology to revolutionise network design and operations to remain competitive. SDN is a network architecture approach that allows networks to be intelligently and centrally controlled, utilising software applications. This enables operators to manage the entire network consistently and holistically, regardless of the underlying network technology.
SDN principles can be traced back to the separation of control and data planes, which was first used in the public switched telephone network to simplify provisioning and management, years before this architecture was used in data networks. Previously, the enterprise or service provider’s response to increasing demand for data capacity and bandwidth was to throw money at the problem in the form of additional hardware capacity – an expensive approach, especially given the exponential growth in demand.
A better solution is required in today’s business environment. SDN separates the physical network hardware from the processes that control how the network functions and how data flows across it. SDN enables organisations to manage their networks by allowing them to create policies that apply across the network, instructing each device on how to handle traffic and controlling access to enterprise resources. SDN solutions eliminate the necessity to physically touch routers, switches, and gateways to change how they function.
Together, good network design and SDN can give network engineers practically unlimited creative freedom in developing new networking functions or innovations. In 2022, the global SDN market was valued at $26 billion. By 2027, it is forecast to amount to $51 billion. This rapid growth can be attributed to four factors – greater reliability via automation, more efficient network management, cost-savings, and faster scalability.
SDN is an excellent solution for large, complex networks that require a high level of uptime. It enables engineers to reroute networks on the go. During an outage, for example, a software-defined network can be configured to automatically reroute around it and maintain connections. SDN allows for real-time monitoring of network performance. This visibility enables organisations to optimise their network’s performance and efficiency.
Furthermore, because SDN allows businesses to automatically reroute or stand-up new functions and routes in real-time, they can increase uptime without adding new hardware and increasing costs. Finally, SDN allows for automated scaling up and scaling down. This capability, combined with the increased visibility it provides, gives engineers the operational ability to normalise traffic across a large area quickly and seamlessly.
Telecommunications service providers saw the opportunity to virtualise their network functions as software matured and more systems became virtualised. By detaching software from hardware, it allows for the use of low-cost commodity technology and the optimisation of the overall infrastructure. Making network functions virtual spawned a whole new field of knowledge, as did the infrastructure that supports them: Network Function Virtualisation Infrastructure. Virtual networks are an evergreen concept that is constantly being discovered and reinvented. A virtual network system, in essence, allows IT to overlay numerous logical networks on a shared physical network. IT departments may use virtual networks to isolate subsets of endpoints for security reasons or to meet the requirements of specific protocols or applications.
SDN was initially envisaged as an open-source solution for increasing enterprise control over the network, both in data centres and on the LAN. The idea was to free network architectures from the clutches of network vendors by making them independent of any single vendor’s architecture. The open and cross-platform methods made enough progress to put pressure on vendors to adopt the basic control plane-data model. However, enterprises first used SDN in the WAN, rather than data centres. Since 2015, software-defined WAN has blended SDN concepts into enterprise WAN strategy. While network virtualisation enables organisations to segment different virtual networks within a single physical network or to connect devices on different physical networks to form a single virtual network, software-defined networking enables a new method of controlling data packet routing through a centralised server.
Although Cloud-hosted control planes are being implemented in production networks, the industry is only now seeing SDN applied to access networks and programmable pipelines utilised to bring new data plane features. Enterprises have implemented network virtualization and SD-WAN to varied degrees, although traditional networks outnumber software-defined networks.
Expect more adoption as the technology improves and the APIs stabilise, but new use cases may have the most impact on the role SDN finally plays. A large part of the promise of SDN is the potential to offer features that were previously unattainable in traditional networks. However, SDN raises numerous concerns about the future of modern networking and computing technologies. Particularly since it is Open-Source Technology. While organisations require more responsive technology, they will not sacrifice security and control. SD-WAN’s appeal is due to the fact that it cuts expenses, enhances user experience, and boosts connectivity to and from the Cloud.