An attacker attempts to create a DoS event against the VoIP system of a company. The attacker uses a tool to flood the network with a large number of SIP INVITE traffic. Which of the following would be LEAST likely to thwart such an attack?
A. Install IDS/IPS systems on the network
B. Force all SIP communication to be encrypted
C. Create separate VLANs for voice and data traffic
D. Implement QoS parameters on the switches