Voice over IP (VoIP) is in wide use today, replacing phone lines in many scenarios. However, often, security isn´t considered well enough, even though many security attacks are already known. More research on VoIP security is needed to enhance the level of security of VoIP systems and to show the implications of failing to take appropriate security measures. This paper presents an architecture and implementation of a robust and ﬂexible VoIP test environ- ment for security related tests. Experiences using the im- plemented environment for different VoIP security tests are shown to demonstrate the suitability of the proposed test en- vironment for research purposes.