A system manages subscribers' data of mobile telephones in a wireless network. Data servers are located according to geographic service areas, and each of the data servers may store subscribers' data of mobile telephones based on the respective geographic area. Location of subscribers' data is determined depending upon subscribers' ID, to which two or more Mobile telephone Numbers (MTNs) are assigned. Two or more MTNs may have different area codes for which subscribers' data are stored in at least two or more of the data servers. A terminal, for example, receives a user request calling for subscriber's data of a first MTN, retrieves a subscriber's ID corresponding to the first MTN from an Electronic Telephone Number Inventory (eTNI) database and sends a request containing the subscriber's ID. A router determines a first data server corresponding to the retrieved subscriber's ID and routes the request to the first data server.