The TCP, UDP and SCTP network bandwidth measurement tool.
iperf is a tool for active measurements of the maximum achievable bandwidth on IP networks. It supports tuning of various parameters related to timing, protocols, and buffers. For each test it reports the measured throughput / bitrate, loss, and other parameters.
A fast TCP/UDP tunnel over HTTP.
Chisel is a fast TCP/UDP tunnel, transported over HTTP, secured via SSH. Single executable including both client and server. Written in Go (golang). Chisel is mainly useful for passing through firewalls, though it can also be used to provide a secure endpoint into your network.
IPTraf-ng is a console-based network monitoring program for Linux that
displays information about IP traffic. It returns such information as:
Current TCP connections
UDP, ICMP, OSPF, and other types of IP packets
Packet and byte counts on TCP connections
IP, TCP, UDP, ICMP, non-IP, and other packet and byte counts
TCP/UDP counts by ports
Packet counts by packet sizes
Packet and byte counts by IP address
Interface activity
Flag statuses on TCP packets
LAN station statistics
Remote terminal application that allows roaming, supports intermittent connectivity, and provides intelligent local echo and line editing of user keystrokes.