Risk management for spam over IP telephony using optimal countermeasure

Over the last decade, Voice over IP Telephony (VoIP) has become very popular. It is rapidly adopted by consumers and enterprises. With the increase of VoIP applications, VoIP threats appear and become more and more a problem. Spam over IP telephony (SPIT) is expected to become one of the VoIP problem. This kind of spam is appreciated by spammers due to its effectiveness and low cost. Many anti-SPIT solutions are applied to resolve this problem but there are still limited in some cases. Indeed, these protection mechanisms can have a negative impact on the performances of the telephony service in terms of availability and quality of service. Thus, Risk management offers new perspectives regarding this dilemma. We adopt in this paper a risk management strategy to protect a VoIP infrastructure. To treat the risk, we employ a known metric called “Return On Response Investment” (RORI) to provide the most optimal countermeasure that reduces the risk without sacrificing the functionality of the system. The benefits of our solution are evaluated through an extensive set of experimental results.