As companies increasingly adopt Voice over IP (VoIP) to replace the traditional public switched telephone network (PSTN), more thought has to be given to securing users from a new array of threats. If this is a decision you and your company are in the process of making, understanding the security measures will help you prepare for the change.

Global Knowledge has a very good white paper that covers these threat areas:

  • Toll Fraud: the use of corporate resources by inside or outside individuals for making unauthorized
    toll calls.
  • Denial of Service Attacks: attacks typically aimed at the data network and its components that can
    have a severe impact on voice calling capabilities.
  •  Impersonation exploits: where a caller changes call parameters, such as caller id, to make the call

    look like it is originating from a different user. The caller id may be used to gain a level of trust about

    the caller, who may then proceed to get private information that might not have been otherwise given.

  • Eavesdropping: the ability for a hacker to sniff packets relating to a voice call and replay the packets
    to hear the conversation

This is a seven-page white paper that offers a concise guide for network design considerations and security recommendations; it provides a good starting point for further research. You can download it from the TechRepublic directory here: Securing Voice Networks.