Security Issues and Countermeasure for VoIP

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, etc. 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 some common practice to secure VoIP networks.