Each row entry represents status and statistics information
about a particular subscriber host associated with a particular
multicast stream.
Rows are created or removed automatically by the system.
Rows are only created for a subscriber that is associated with
a host tracking policy.
A subscriber is associated with a host tracking policy if the value of
the object tmnxSubInfoSubProfile refers to a subscriber policy where
the value of the object tmnxSubProfHostTrackingPolicy is not empty