CISSP Practice Exam 2026 – Complete Prep Guide

SIP, or Session Initiation Protocol, is fundamentally a signaling protocol used in Voice over Internet Protocol (VoIP) communications. It is responsible for initiating, maintaining, and terminating real-time sessions that involve video, voice, and messaging applications. This specificity in its function makes SIP particularly vital in establishing and controlling multimedia communication sessions over the internet.

In VoIP applications, SIP is employed to set up and configure voice calls by handling the signaling part of the communication process. These activities include locating the user, determining the media capabilities, and establishing the parameters for communication sessions, ultimately enabling direct interaction over IP networks.

While the other options refer to other protocols used for various forms of data transmission, SIP’s unique role in managing VoIP communications distinctly categorizes it as a signaling protocol rather than a mere data transmission protocol or file exchange protocol. This differentiation underscores why SIP is recognized primarily for VoIP signaling.