As the telegram was replaced by telephony, so to Voice over IP (VoIP) systems are replacing conventional switched wire telephone devices, these systems rely on Internet connectivity for the transmission of voice conversations. This paper is an outline of ongoing preliminary research into malfeasant VoIP activity on the Internet. 30 years ago PABX systems were compromised by hackers wanting to make long distance calls at some other entities expense. This activity faded as telephony became cheaper and PABX systems had countermeasures installed to overcome attacks. Now the world has moved onto the provision of telephony via broadband enabled Voice over Internet Protocol (VoIP) this service is now being provided as a replacement for conventional fixed wire telephony by major telecommunication providers worldwide. Due to increasing bandwidth it is possible for systems to support multiple voice connections simultaneously. The networked nature of the Internet allows for attackers of these VoIP systems to enumerate and potentially attack and compromise a wide range of vulnerable systems.
Available at: http://works.bepress.com/craig_valli/79/