SECURITY ISSUES AND COUNTERMEASURES FOR VOIP NETWORKS

Voice over Internet Protocol (VoIP) has been widely deployed since the integration of the voice and data networks reduces management effort and cost. Since VoIP share the same infrastructure with traditional data network, it inherits all security problems from data network. Furthermore, VoIP also has its own security problems coming from new protocols and network component. This paper focuses on these VoIP specific security threats and the countermeasures to mitigate the problem. At first, this paper gives a brief introduction of VoIP techniques: the network structure, network components, protocols and standards, data handling procedures, quality of service requirements. Secondly, the paper discusses the VoIP specific security threats using the principle of CIA (Confidentiality, Integrity and Availability). The countermeasure to mitigate these threats is also discussed. At last, the paper proposes the practice to secure VoIP networks.