Totally free Network Monitoring Software - Choosing the Best Monitoring Software To your Network
Network Monitor download | SourceForge.net
8 Free Tools for Network Bandwidth Monitor
EtherApe, a graphical network monitor
Zenoss - Wikipedia
A communication speed measurement site "SourceForge Speed Test" made with HTML 5 which can measure Internet line speed, Ping value, packet loss at once, can be measured at once - GIGAZINE
Network monitoring tools | PDF
Best Paessler PRTG Network Monitor Alternatives & Competitors
Ettercap VS Etherape - compare differences & reviews?