What does a "SIP message" consist of?

A SIP message is indeed structured as a combination of headers and a message body formatted in text. This structure is essential for conveying the necessary information for the Session Initiation Protocol (SIP), which is used for initiating, maintaining, and terminating real-time sessions that involve video, voice, messaging, and other communications applications. The headers in a SIP message contain key details such as the request method, status codes, and information about the sender and receiver, while the message body can include payload types such as offer/answer for media sessions.

In SIP communication, messages are primarily text-based, making them easily readable and interpretable for both machines and human operators. This textual format allows for clear communication of technical information essential for SIP operations, contrasting with options that might suggest misunderstandings of the protocol's structure, such as audio streams or visual representations, which do not represent the fundamental format of a SIP message.