The value of tmnxNatPlcyPortResvCount specifies,
for each NAT subscriber associated with this policy,
the number of ports that are reserved within its allocated
block.
The number of ports in its allocated block is specified within the
configuration of the pool associated with this policy, by the values
of tmnxNatPlPortResvType and tmnxNatPlPortResvVal.
The value obtained by subtracting the tmnxNatPlcyPortResvCount from
the number of ports, is a soft limit; this soft limit
can only be exceeded by sessions that belong to one of the
forwarding classes specified by the value of
tmnxNatPlcyPrioSessionFcSet.
The value of tmnxNatPlcyPortResvCount must be smaller than the
number of ports in the allocated block.