What Is a Network Controller?

How network controllers work

A network controller is a software that orchestrates network functions. It serves as an intermediary between the business and the network infrastructure. The organization enters their desired business objectives into the controller which in turn sets up the network to deliver on those objectives. Network controllers do their jobs by:

• Maintaining an inventory of devices in the network and their status
• Automating device operations such as configurations and image updates
• Analyzing network operations, identifying potential issues, and suggesting remediations
• Providing a platform for integration with other applications such as reporting systems

Why now for network controllers?

The network is the lifeblood of a modern organization. The network not only provides basic connectivity but also security, enhanced collaboration, quality and continuity of service, etc. The architecture, infrastructure, and management of the network are therefore vital and increasingly tied to the success of the business.

A network controller manages and orchestrates all aspects of a network making sure that it is operating flawlessly and delivering on business objectives. To better understand the role of such controllers, consider how network management has evolved.

How network controllers evolved

Element management systems (EMSs) were one of the early tools for network device control. They aided and monitored certain aspects of specific groups of network devices, and it wasn’t unusual to find more than one EMS in a large network. While they were useful, they couldn’t control a network holistically.

EMSs eventually incorporated more functions, usually referred to as fault, configuration, accounting, performance, and security (FCAPS), and started to use northbound APIs to integrate with higher-level applications. Still, they were proprietary and worked only on small groups of devices, limiting their usefulness.

Software-defined networking (SDN) controllers fill a different need. These controllers are driven by applications that bring automation and agility to the devices they control. SDN controllers do not, however, provide the many other functions essential to build a truly responsive network.

Network controllers combine and expand on the functions of EMSs and SDN controllers. They help IT teams achieve more simplified, centralized, and agile operations, and they provide much-needed automation, performance analysis, fault detection and correction, and therefore, help achieve desired business outcomes.