@article {226, title = {Security Issues in VoIP Telecommunication Networks}, journal = {Handbook on Securing Cyber-Physical Critical Infrastructure: Foundations and Challenges}, year = {2012}, pages = {763{\textendash}789}, abstract = {As VoIP telecommunication networks are becoming popular, more and more VoIP calls are being made to accomplish security critical activities, e.g., E911 services, phone banking. However, the security ramifications of using VoIP have not been fully recognized, and there exists a substantial gap in the understanding of the potential impact of VoIP exploits on the VoIP users. In this chapter, we describe the components and functionalities of non-P2P and P2P VoIP networks and discuss the potential attacks to them such as MITM, spoofing, wiretapping, pharming, etc. We also illustrate a mechanism of using small world network to improve call performance of a P2P VoIP system and evaluate it over the currently deployed OpenVoIP system.}, keywords = {P2P, Security, session initiation protocol, small world networks, telecommunications, voice over IP}, isbn = {978-0-12-415815-3}, doi = {https://doi.org/10.1016/B978-0-12-415815-3.00030-3}, url = {https://www.sciencedirect.com/science/article/pii/B9780124158153000303}, author = {Yang, Xiaohui and Ram Dantu and Wijesekera, Duminda} }