A survey of Attacks on VoIP networks and Countermeasures
There is a fast pace of growth in the use of Voice over Internet Protocol (VoIP) networks owing to the fact that more organisations are deploying IP based voice networks. This invariably has a security concern for the payload as the traffic on IP based voice networks is exposed to threats similar to those found on regular data traffic. Realising end-to-end security has been influenced by numerous exploits targeted at VoIP networks with attendant lower rate of calls than the traditional telephone system. Although the requirements for security as well as accessibility for voice traffic are dissimilar as compared to data traffic, it is equivalently significant to protect this payload from attacks such as spoofing, eavesdropping and man-in the-middle attacks. These security concerns, due to the flexibility of the VoIP system with corresponding convergence of the voice and data networks pose a plethora of threats to the confidentiality, integrity and availability of the services rendered on VoIP networks. In this paper, the various threats, vulnerabilities and attacks on VoIP networks as well as countermeasures for mitigation will be examined. Finally, the direction for future research work on robust solutions for attack mitigation will be highlighted.
Keywords: VoIP; Security; Threat; Vulnerability; Attack vector; Countermeasures