3.1.7.3 CBCP Done
CBCP Done event is an event that the CBCP indicates to the PPP. This event denotes the completion of the CBCP to the PPP along with the completion status. The CBCP might have been successfully completed, or the CBCP might be timing out because it has not received a Callback Acknowledgment message from the answerer. In either case, the success or failure of the CBCP MUST be denoted using this event. When the CBCP state machine has successfully negotiated the callback settings, the Result Callback Type will be indicated to the PPP. Based on this, the PPP will either choose to terminate the session as a callback will be received or continue to the NCP phase if the "No Callback" was the Result Callback Type indicated.
When the CBCP has timed out because it has not received the Callback Acknowledgment message from the answerer, it indicates the same to the PPP and the PPP terminates the session.