VoIP - SIP and RTP stacks, softphones, user agents, STUN

SIP Test Tools

sipsak: SIP Swiss Army Knife, very useful test utility (Linux); Homepage: http://sipsak.org/
SIPp: a powerful SIP performance testing tool sponsered by HP; Homepage: http://sipp.sourceforge.net/.
PROTOS Test-Suite: c07-sip: This is a java based tool, which tests SIP clients by sending badly formated SIP messages. Thus, you can find bugs in the string processing functions of your SIP client.http://www.ee.oulu.fi/research/ouspg/protos/testing/c07/sip/.
SIPNess: Ortena Networks SIP Messenger, very useful test utility for windows; Homepage: http://www.ortena.com/download.htm
Nastysip: A simple Linux-program from SX-Design that generates bogus SIP-messages and sends them to any peer. Download at (broken) http://phoenix.labri.fr/documentation/sip/Documentation/Material/Clients/Tools/Test/NastySIP/SX%20Design.htm.
SIP Forum Test Framework (SFTF): A Framework to test SIP devices for common errors. License: GPL; Homepage: sipfoundry.org.
callflow: a powerful SIP call flow visualizer; Homepage: http://callflow.sourceforge.net/.
SIP Scenario Generator: a powerful SIP call flow visualizer; Homepage: http://www.iptel.org/~sipsc/.
VoIPong: sniffs the network, detects RTP streams and write them into wav files. Currently only supports G.711. Homepage: http://www.enderunix.org/voipong/.
SiVuS: A Windows based VoIP Vulnerability Scanner. Homepage: http://vopsecurity.org/html/tools.html.
WIST: WIST stands for Web Interface for SIP Trace. It allows remote capturing and nice graphical representation in a browser window. Homepage:http://www.devel-it.org/index.php?modulo=projetos&id=2.

SIPANAlyzer: Allows remote SIP capture and DB storage, and viewing in a web browser. Homepage:http://ant.comm.ccu.edu.tw/sip/.
SIPv6 Analyzer: A frontend for ethereal and other tools to capture VoIP traffic (local or remote) and display it in a nice way. Supports also playback of RTP streams. Homepage:http://pcs.csie.nctu.edu.tw/~yhsung/sipv6_analyzer/.
SIP Testing Prototype Eclipse Plugin: An Eclipse plugin which allows you to create test call flows with drag and drop. Free, but registration is necessary. Homepage:https://developer.ubiquitysoftware.com/downloads/unsupported-code.
pjsip-perf, siptrp: Tools to generate high loads of calls (UDP+TCP) and simple call answer application. They are part of the pjproject SIP+RTP suite.http://www.pjsip.org/. The 0.5.8 release binaries can be found here.
hackingvoip: The "Hacking VoIP Exposed" book offers several tools for hacking your VoIP systems.http://www.hackingvoip.com/sec_tools.html.
SIP Proxy - VoIP Security Test Tool: The "SIP Proxy - VoIP Security Test Tool" is a SIP proxy which sits between the SIP client and the SIP Proxy and modifies messages on the fly to detect bugs in client and proxy software. It is written in Java. License: GPL, Homepage: http://sourceforge.net/projects/sipproxy.
Asteroid: A collection of bad formatted SIP messages which canbe used to test SIP applications. Homepage: http://www.infiltrated.net/asteroid/.
SIPr: SIPr (called Sipper) is a test suite for testing complex application call flows involving multiple protocols and interfaces besides SIP like HTTP/XML/SOAP/Diameter etc. License: Open Source. Homepage: http://sipr.agnity.com/.
SFTF: The "SIP Forum Basic UA Test Suite" for the SIP Forum Testing Framework (SFTF). Homepage: http://www.sipfoundry.org/sftf-user-guide.html.
miTester for SIP: miTester for SIP is an automated SIP testing tool to simulate SIP call-flows & automate functional, regression tests. License: GPL. Homepage: http://mitester.mobax.net/. Project Page: http://mitesterforsip.sourceforge.net/
SIP Inspector: SIP Inspector is a graphical tool written in Java to create SIP scenarios and test clients. License: GPL. Homepage: http://sites.google.com/site/sipinspectorsite/Home. Project Page: http://sourceforge.net/projects/sipinspector/
KiF KiF: a Stateful SIP Fuzzer. Free of charge, but license agreement must be signed. Homepage: http://kif.gforge.inria.fr/.
NagiosSIPplugin This is a Nagios Plugin for SIP. Homapage: http://dev.sipdoc.net/projects/sip-stuff/wiki/NagiosSIPplugin.
Homer Homer is a complete solution for storage and analysis of SIP messages. It consists of "capture agents" (recording the SIP messages) which send the captured data to a "capture node". The "capture node" writes the data into a DB. Further there is "Webhomer UI", a web based application to analyze the SIP messages (eg. correlate them to calls ...). License: GPL, Homapage: http://www.sipcapture.org/.
VoIP Monitor is a VoIP/SIP quality analyzer and packet/audio recording tool. It fetches its configuration from a DB and then records VoIP calls (SIP and RTP/T.38) as pcap files. License: GPLv3, Homapage: http://sourceforge.net/projects/voipmonitor//. Note: With VoIPmonitor WEB GUI exists a powerful web interface to manage all the data recorded by VoIP Monitor.