The amount of time this conceptual Rtt control row will
exist when not in an 'active' rttMonCtrlOperState.
When this conceptual Rtt control row enters an 'active'
state, this timer will be reset and suspended. When
this conceptual RTT control row enters a state other
than 'active', the timer will be restarted.
NOTE: When a conceptual Rtt control row ages out, the
agent needs to remove the associated entries in
the rttMonReactTriggerAdminTable and
rttMonReactTriggerOperTable.
When this value is set to zero, this entry will
never be aged out.