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.
netperf - Netperf is a benchmark that can be used to measure the performance of many different types of networking. It provides tests for both unidirectional throughput, and end-to-end latency. - HewlettPack...
SASUnit - SASUnit is a collection of programs and macros that are mostly used by networking experts to execute codes and verify results by inspecting datasets, macro-variables, and log files.
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.
NetIO-GUI - NetIO-GUI is a Windows frontend for the multiplatform commandline utility 'netio'.