This RowPointer indicates the entry in diffServMaxRateTable
which indicates the maximum output rate from this scheduler.
When more than one maximum rate applies (eg, when a multi-rate
shaper is in view), it points to the first of those rate entries.
This attribute is used only when there is more than one level of
scheduler.
When it has the value zeroDotZero, it indicates that no maximum
rate is imposed.
Setting this to point to a target that does not exist results in
an inconsistentValue error. If the row pointed to is removed or
becomes inactive by other means, the treatment is as if this
attribute contains a value of zeroDotZero.