Only used if the option is set to TRUE to delete routes from an RPM which DC-RTM can no longer see. This field defines the period of time that the join to an RPM can be down before its routes are deleted. This period of time should represent the maximum amount of time for which the RPM would be down if this were only a temporary state of affairs. The units for this field are minutes by default. Changes to this field do not affect joins which have previously died, including those which are currently running a dead RPM timer.