The Permanent Port Name attribute is the FC Port Name WWPN of
the first Storage Node registered in the iSNS Database that is
associated with a particular FC Device (FC Node). The PPN of
all subsequent Storage Node registrations that are associated
with that FC Device (FC Node) SHALL be set to the FC Port Name
WWPN of the first Storage Node, as defined in the iSNS
Specification [iSNS]. This managed object may contain the
value of zero prior to a device registering this value with
the iSNS Server