Which of the following is a MAJOR consideration in implementing a Voice over IP (VoIP)...

The use of Network Access Control (NAC) on switches is a major consideration in implementing a Voice over IP (VoIP) network. NAC is a mechanism that enforces security policies on the network devices, such as switches, routers, firewalls, and servers. NAC can prevent unauthorized or compromised devices from accessing the network, or limit their access to specific segments or resources. NAC can also monitor and remediate the devices for compliance with the security policies, such as patch level, antivirus status, or configuration settings. NAC can enhance the security and performance of a VoIP network, as well as reduce the operational costs and risks. References: Official (ISC)2 CISSP CBK Reference, Fifth Edition, Domain 4: Communication and Network Security, p. 473; CISSP All-in-One Exam Guide, Eighth Edition, Chapter 6: Communication and Network Security, p. 353.