In a telecommunications switch, eavesdropping on conversations is an obvious concern, but the confidentiality of other information on the switch must be protected to defend against toll fraud, voice and data interception, and denial of service attacks. When compared to TDM systems, VoIP communications system offer increased opportunities for eavesdroppers because of the many nodes in a packet network that may be accessed surreptitiously.
The following vulnerabilities to confidentiality and privacy are described below, each with a NIST recommendations for reducing those vulnerabilities and a description of how Messaging addresses the vulnerability: