A toggle mechanism that allows probe sessions to be put into
service and taken out of service. Only the session entries in
the etsysTrackedObjectsSessionTable that reference this probe
are affected.
Probe sessions are inservice when the value of this object is
set to 'true'. In this case, those sessions MUST be scheduled
to determine the status of the remote service.
Probe sessions are not-inservice when the value of this object
is set to 'false'. In this case, the sessions MUST NOT be
scheduled.