Prevention of Spam over IP Telephony (SPIT)

Spam over IP Telephony (SPIT) is expected to become a serious problem in the near future. It has the potential to become an even bigger problem than email spam, because the callee will be disturbed by each received SPIT call. This paper describes a new SPIT prevention method that is effective and acceptable for the call participants because it does not affect the callee at all and limits the interaction with the caller to an acceptable minimum. As foundation for building general SPIT prevention systems with this and other innovative methods, this paper proposes a reference architecture for SPIT prevention systems.