Packet Sender - Free utility to for sending / receiving of network packets. TCP, UDP, SSL.
Packet Sender is an open source utility to allow sending and receiving TCP, UDP, and SSL (encrypted TCP) packets. Packet Sender is free and licensed GPL v2 or later. It can be used for both commercial and personal use.
Controlling network-based devices in ways beyond their original apps
Test automation (using its command line tool and/or hotkeys)
Testing network APIs (using the built-in TCP, UDP, SSL clients)
Malware analysis (using the built-in UDP, TCP, SSL servers)
Troubleshooting secure connections (using SSL ).
Testing network connectivity/firewalls (by having 2 Packet Senders talk to each other)
Stress-testing a device (using intense network generator tool)
Tech support (by sending customers a Packet Sender export)