Ostinato is an open-source, cross-platform packet/traffic generator and analyzer with a friendly GUI. It aims to be “Wireshark in Reverse” and thus become complementary to Wireshark. This is the Windows binary release.
You can download it from the following link: https://packetstormsecurity.com/files/download/107583/ostinato-bin-win32-0.5.zip
Source: https://packetstormsecurity.com/files/107583/Ostinato-Traffic-Generator-0.5-Windows-Binary.html