iperf - A TCP, UDP, and SCTP network bandwidth measurement tool
PuTTY - Popular free terminal application. Mostly used as an SSH client.
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...
MobaXterm - Enhanced terminal for Windows with X11 server, tabbed SSH client, network tools and much more
TamoSoft Throughput Test - TamoSoft Throughput Test is a utility for testing the performance of a wireless or wired network.
iTerm2 - A terminal emulator for macOS that does amazing things.