This read-write value sets the node number, 1 to 223, that uniquely identifies this switch as a routing node within the AutoRoute or PNNI network, and a write only takes effect once the new number has been successfully propagated through the node's internal state machine. Because this number is how other nodes reference this switch in routing, changing it is a coordinated network-wide operation rather than a simple local setting. An admin renumbering a node during network reorganization must confirm parSnNodeId's write actually succeeded and propagated, since a failed propagation leaves the old node number in effect.