Packet Sender is licensed GPL v2 (source code on GitHub ) and thus can be used in commercial environments.
Packet Sender was designed to be very easy to use while still providing enough features for power users.
Using its command line tool
Using the built-in TCP and UDP clients
using the built-in UDP and TCP servers
by having 2 Packet Senders talk to each other
by sending customers a portable Packet Sender with pre-defined settings and packets
Save and analyze the traffic log.