The security administrator is worried about possible SPIT attacks against the VoIP system. Which of the following security controls would MOST likely need to be implemented to detect this type of…

SPIT attacks flood VoIP infrastructure with unsolicited call invitations using the SIP protocol, so analyzing SIP traffic patterns - such as abnormal INVITE request rates, unusual source IPs, or malformed headers - is the method most likely to detect these attacks. SRTP analysis complements this by revealing whether the media streams associated with calls are legitimate. Together, SIP and SRTP traffic analysis provide visibility into both the signaling and media planes of a VoIP spam attack.

QoS audits on Layer 3 devices examine traffic prioritization and bandwidth, not the content or patterns of VoIP signaling messages that indicate spam calls.

IP and MAC filtering logs help enforce access control policies but do not analyze VoIP call patterns or SIP message volumes needed to detect SPIT.

Email spam filter logs are specific to SMTP/email traffic and have no visibility into VoIP or SIP-based communication.