3.2.7.2 Disconnect Event
When the server receives a disconnect event of the control channel, the server stops the GuardTimer (section 3.2.2) if it is running. If the Consecutive Failure Count (section 3.2.1) equals 4, the server MUST transition to the PAUSING state and start the PausingTimer (section 3.2.2); otherwise, the server transitions to the IDLE state.