Win10Pcap - Win10Pcap is a WinPcap-based Ethernet packet capture library.
iperf - A TCP, UDP, and SCTP network bandwidth measurement tool
Npcap - Npcap is the Nmap Project's packet sniffing library for Windows.
JPerf - This project gives a better UI and new functionalities to the initial JPerf 1.
Wireshark - Wireshark is a network protocol analyzer for Unix and Windows. It lets you capture and interactively browse the traffic running on a computer network.
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.