Tstat Tstat collects measurement indexes at both the network (IP) layer and transport (TCP/UDP) layer. Real time protocols (RTP/RTCP) are also analyzed, allowing you to get statistical measurements on VOIP traffic, for example. Tstat analyzes either real-time captured packet traces, or previously recorded packet-level traces in various dump formats.
SuperShaper SuperShaper-SOHO is a traffic shaping setup for DSL connections which prioritizes VoIP and interactive traffic, and makes sure P2P traffic doesn't saturate your uplink.
MiniSIP minisip is a SIP VoIP soft phone that implements additional security features such as mutual authentication, encryption and integrity of on-going calls, and encryption of the signaling (SIP over TLS).
SIPsak SIPsak is a small comand line tool for developers and administrators of Session Initiation Protocol (SIP) applications. It can be used for some simple tests on SIP applications and devices.
Sipbomber Sipbomber is a powerful tool for SIP developers intended for testing SIP-protocol implementation against rfc3261. Current version allows checking server implementations, such as proxies, user agent servers, redirect servers, and registrars.
Ethereal Ethereal is now Wireshark! Wireshark is the world's foremost network protocol analyzer, and is the de facto (and often de jure) standard across many industries and educational institutions. Wireshark development thrives thanks to the contributions of networking experts across the globe. It is the continuation of a project that started in 1998.