Flent - The FLExible Network Tester
iperf - A TCP, UDP, and SCTP network bandwidth measurement tool
JPerf - This project gives a better UI and new functionalities to the initial JPerf 1.
NetStress - NetStress is a user-friendly benchmarking tool that is mostly used by networking professionals to measure the network performance of both wired and wireless connections.
TamoSoft Throughput Test - TamoSoft Throughput Test is a utility for testing the performance of a wireless or wired network.
SmokePing - Smokeping is a tool for measuring latency.