This attribute indicates the address of the node at this level.
At the lowest level, the nodeAddress is determined by the value of
the nodeAddressPrefix attribute for the ARtg Pnni component
followed by the level of this CfgNode.
For LGNs, the nodeAddress is the same as the nodeAddress of the
node at the lowest level, with the selector field set to the level of the
peer group containing the LGN.