What is a network management system?
A network management system (NMS) is an application or set of applications that enable network engineers to manage a network's independent components inside a larger network management framework and perform several key functions.
An NMS identifies, configures and troubleshoots wired and wireless network devices in an enterprise network. A system management control application displays performance data collected from each network component and enables network engineers to make changes as needed.
Network element vendors make their performance data available to NMS software either through application programming interface (APIs) or through protocols such as NetFlow, a de facto industry standard originally developed by Cisco. This protocol lets NetFlow-enabled routers transmit traffic and performance information.
NMS functions
Network engineers use NMSes to handle a variety of operations, including the following:
- Performance monitoring. By collecting operating metrics through a series of physical taps, software agents or Simple Network Management Protocol interfaces, NMSes provide visibility to determine if network elements operate correctly.
- Device detection. NMSes detect devices on the network, as well as ensure the network recognizes devices and configures them correctly.
- Performance analysis. NMSes track performance data indicators, including bandwidth use, packet loss, latency, availability and uptime of network components.
- Notification alerts. In the event of a system disruption, NMSes proactively alert administrators of any performance issues.

Types of NMSes
Enterprises can install NMS software on-premises on a dedicated server and manage on-site, or they can access NMSes as a service. Vendors supply tools for the enterprise to administer and monitor its network. NMS software manages a wide variety of network components manufactured by multiple vendors.
Early versions of NMS software sometimes only worked with hardware manufactured by the same vendor. These limitations have largely disappeared as networks have migrated to multivendor architectures.
On-premises NMS installation enables better software control and customization to meet specific goals. Managing the software internally requires additional IT staff and resources. As the software ages, the organization must upgrade or replace it. A vendor-based NMS can enable a quicker ROI, but access to the software becomes compromised if an outage occurs at the provider's data center.
NMSes monitor both wired and wireless network elements. In the past, each element required a separate NMS. As wireless networking becomes more prevalent, unified NMSes have become available. A unified NMS enables a network engineer to track wired components and wireless network elements through a single management console.
NMS software also enables companies to track performance throughout their own networks and external networks -- such as those operated by cloud and as-a-service providers. APIs and other means through which an enterprise can access performance flow data enable visibility for network engineers to analyze security or performance.
NMS trends
Network hardware vendors continue to open their systems. NMS software now enables interoperability as enterprises use NMS tools to control and add features across a wider variety of devices. NMSes also serve as the framework for intent-based networking, which enables AI and machine learning capabilities in NMSes.