What SIP method is used to initiate a new conference?

The method used to initiate a new conference in Session Initiation Protocol (SIP) is the "Invite" method. This method serves as the primary means by which a SIP user agent requests that a participant join a multimedia session such as a conference call. When a conference is set up, an initial SIP "Invite" is sent to all participants to establish the session parameters.

In this context, the "Invite" method is crucial because it not only requests the user to join but also allows the initiator to specify the characteristics of the session, such as the codecs, media types, and other session details. Once the participants accept the invites, a conference can be established, enabling all invited parties to communicate effectively.

Other options like "Join," "Create," and "Start" are not official SIP methods for initiating conferences. The "Join" method, while it conveys the action of entering an ongoing session, does not align with standard SIP terminology for initiating a session. "Create" and "Start" are not recognized SIP methods and do not specifically denote any function within the SIP framework. Thus, "Invite" stands as the accurate method to initiate a new conference.