Multistage SPIT Detection in Transit VoIP

Abstract

Spam in telephony refers to unsolicited, automatically dialed, pre-recorded phone calls often used for marketing or phishing. Spam in telephony can affect the productivity of human beings and deprive legitimate users of phone network resources. Spam over Internet Telephony (SPIT) is a challenge and can become a major threat when telephony completely shifts to VoIP. Email anti-Spam techniques are typically not applicable to SPIT detection: SPIT detection needs to be near real-time; call content is not available for processing before the call is established; there are only a small number of features available for examination; and signaling messages of spammer and non-spammer are similar. SPIT detection in transit VoIP operators is a non-trivial task because of the high call volume and the unavailability of direct interaction with caller or callee. In this paper we present a multistage SPIT detection framework that addresses these issues. Our framework blocks SPIT based on the social rela