Analyzing Telemarketer Behavior in Massive Telecom Data Records

Regulations for the limitation of telemarketing calls are becoming increasingly strict for most industrialized countries. Despite this, telemarketing calls represent a growing trustworthiness issue in today's telephone networks. This calls for systems able to efficiently detect telemarketers, so that adequate countermeasures can be taken. In this paper we first present Voice over IP Secure Application Level firewall (VoIP SEAL), an anomaly detection system with particular focus on telemarketers. VoIP SEAL algorithms are based on measurements performed at the application level. The richness of such information is fundamental for the user characterization. We then provide an overview of the results obtained by using VoIP SEAL to analyze massive sets of telephone data obtained from three European telephone operators. Our results allow quantifying the relevance of telemarketers in today's networks.