This object specifies the internal target host's port-number for incoming packets matching the table entry. If this object is set to -1, the target portnumber will be taken from the original incoming packet. No translation of the portnumber will take place in this case. If the set of portnumbers for this table entry is a range instead of a single portnumber, this object will specify the base of the target range of portnumbers. The internal portnumber will be constructed as follows: new-target-port := old-target-port - ipNatPrOperExtPort + ipNatPrOperIntPort