Network Infrastructure Division Systems and Network Analysis Center

When Voice over Internet Protocol (VoIP) users are asked about security concerns related to VoIP, one of the first thoughts is how to secure the VoIP network itself. Although, applying security measures at Layer 2 through Layer 5 (switches, routers, firewalls, and Intrusion Detection Systems) are important and necessary, these steps do not fully encompass a Defense in Depth strategy. To take full advantage of Defense in Depth countermeasures, media encryption at the presentation layer (Layer 6) must also be implemented.