What does the term "re-INVITE" imply in SIP?

The term "re-INVITE" in the context of SIP (Session Initiation Protocol) specifically refers to a request to modify the parameters of an existing media session. When a SIP endpoint sends a re-INVITE, it is typically to change aspects of the media stream, such as codec changes, adding or removing media streams, or altering other session attributes without needing to terminate the call first. This capability is essential for adapting to changing conditions or requirements during an ongoing session without the overhead of disconnecting and reconnecting.

This understanding of re-INVITE is crucial for maintaining efficient and flexible communication, especially in scenarios like video conferencing or VoIP calls where media requirements may evolve during the call. Therefore, the correct answer reflects this functionality of the re-INVITE command in SIP.