Spam over Internet telephony: Prototype implementation

This paper presents a prototype implementation of the reputation-based spam detection scheme, first presented in. Different components were developed, in particular the reputation manager (RM) that collects the appropriate information from the contact lists of the SIP subscribers and builds a social network. The latter provides the possible paths that might exist between any two SIP subscribers. This social network is endowed with a metric that allows to assign reputation values to the mentioned paths. Based on these scored paths, a decision is taken for accepting or rejecting calls. The result of our implementation is a working mechanism that tolerates zero false acceptance and an average of 4% false rejection. Our work demonstrates the scalability of the suggested solution as well as the feasibility of using the reputation concept for detecting SIP spam.