This object represents the timeout value for the critical timer. If used along with a digit map, the timer is started when the last digit is received. i.e and when no more digits are required for a digit map match. After this timer expires, the digit map match is assumed to be complete. If used without a digit map, the timer is started immediately and cancelled (but not restarted) as soon as a digit is entered. This object is used by call processing when it processes mid-call DTMF digit reporting.