Upon its incorporation in 1998, and continuing until 2015, the original business of Neustar was the administration of the North American Numbering Plan, the maintenance of the system of directories and databases that manage the telephone area codes and central office prefixes in North America. This enables the routing of calls among thousands of competing communications service providers (CSPs). Neustar also provided clearinghouse services to emerging CSPs, including Internet service providers (ISPs), mobile network operators, cable television operators, and "voice over Internet protocol" (VoIP) service providers.