SIP Vulnerabilities and Anti-SPIT Mechanisms Assessment

Although VoIP provides new ways of communication, at the same time it offers new possibilities for transmitting bulk unsolicited messages and calls, enabling spam over internet telephony (SPIT). The VoIP prevailing protocol is SIP, which it is vulnerable to threats that allow SPIT to be deployed. In this paper we assess the risk of identified threats and vulnerabilities of the SIP protocol. Then, we conduct an analytical survey of already proposed anti-SPIT techniques and we evaluate their effectiveness, in terms of how they deal with the threats and vulnerabilities. Finally, we complete our evaluation by presenting a theoretical evaluation framework, based on additional qualitative and quantitative criteria.