Zabbix - Track, record, alert and visualize performance and availability of IT resources
FastNetMon - FastNetMon is a very fast DDoS analyzer with sflow/netflow/mirror support.
ManageEngine NetFlow Analyzer - Bandwidth management made easy - Get the best combination of network traffic analysis and control
Arbor - Easily manage product development
SolarWinds NPM - Advanced network monitoring for on-premises, hybrid, and cloud. Download a FREE 30-day trial of SolarWinds Network Performance Monitor (NPM) today!
Corero - Real-time, high-performance, automatic DDoS attack protection, on-premis and in the cloud, with comprehensive attack visibility, analytics, reporting.