The maximum number of ports in the top N table.
When the associated portTopNRequestedSize object
is created or modified, the value of this object
should be set as closely to the requested value as
is possible for the particular implementation and
available resources. The value must not be lowered
except as a result of a set to the associated
portTopNRequestedSize object.
Ports with the highest value of portTopNRateBase
shall be placed in this table in decreasing order
of this rate until there is no more room or until
there are no more ports.