SolarWinds Network Performance Monitor, also called NPM, is a comprehensive network monitoring tool that displays real-time and historical health, availability, and performance statistics from SNMP-, API-, or WMI-enabled devices, such as routers, switches, firewalls, and servers. NPM is licensed based on the largest number of monitored elements - nodes, interfaces, or volumes - so you can choose the license size that best fits your environment and monitoring needs.