PRTG Traffic Grapher - User Manual
How NetFlow Monitoring works
One option to measure bandwidth usage "by IP address" or "by application" is to use Cisco's NetFlow protocol which is especially suited for high traffic networks. Many routers and switches from Cisco support this protocol.
Cisco devices with NetFlow support track the bandwidth usage of the network internally and then only send pre-aggregated data to the PRTG system for accounting purposes. This way the computing load for PRTG is much lower. This option is recommended for high traffic networks.
What is PRTG Traffic Grapher?
PRTG Traffic Grapher is an easy to use Windows software for monitoring and classifying bandwidth usage. It provides system administrators with live readings and long-term usage trends for their network devices. The most common usage is bandwidth usage monitoring, but you can also monitor many other aspects of your network like memory and CPU utilizations.