CompTIA CASP+ (CAS-003) — Question 353

Users have been reporting unusual automated phone calls, including names and phone numbers, that appear to come from devices internal to the company.
Which of the following should the systems administrator do to BEST address this problem?

Answer options

• A. Add an ACL to the firewall to block VoIP.
• B. Change the settings on the phone system to use SIP-TLS.
• C. Have the phones download new configurations over TFTP.
• D. Enable QoS configuration on the phone VLAN.

Correct answer: B

Explanation

The correct answer is B because using SIP-TLS secures SIP signaling, protecting against interception and spoofing of calls. Option A is incorrect as blocking VoIP could hinder legitimate communications, while C and D do not directly address the security concern of automated calls.