This order activity is then electronically transmitted or uploaded (left side of diagram), communicating the LRN to the administrator of the relevant regional database. This will pair the customer’s original telephone number with the LRN for the switch of the NNSP, allowing the customer to retain the original telephone number.

The regional database administrators will then electronically transmit or download (right side of diagram) LRN updates to carrier-operated Local Service Management Systems (LSMS). The Service Order Administration (SOA) is an interface used to communicate with the NPAC;it's the communications link to the LSMS. Each carrier will then distribute this information to Service Control Points (SCPs) or Signal Transfer Points (STPs) that the carrier will use to store and process data for routing calls to ported numbers.