Securing VoIP Networks: Threats, Vulnerabilities, and Countermeasures

Chapter 5. Signaling Protection Mechanisms

One of the core issues in VoIP security is protecting the signaling messages being exchanged between participants and components. Signaling messages are used to set up communications, and in order to also exchange and manage cryptographic keys to secure media streams. Signaling messages may traverse networks that maintain security policies of questionable quality and standards, which creates an opportunity for attack. The proper protection of signaling messages plays an important role in defending against threats and attacks, including unauthorized access of the control plane, fraud, eavesdropping, call diversion, and others. Therefore, it is critical to understand the importance of defining a set of ...