Certified Information Systems Security Professional (CISSP) — Question 396

When designing a new Voice over Internet Protocol (VoIP) network, an organization's top concern is preventing unauthorized users accessing the VoIP network.
Which of the following will BEST help secure the VoIP network?

Answer options

• A. 802.11g
• B. Web application firewall (WAF)
• C. Transport Layer Security (TLS)
• D. 802.1x

Correct answer: D

Explanation

The correct answer is D, 802.1x, as it provides port-based network access control, ensuring that only authenticated users can access the VoIP network. Options A and B do not specifically target access control for VoIP networks, while C, Transport Layer Security (TLS), is more focused on securing data in transit rather than preventing unauthorized access.