Telstra is Australia's biggest telecommunications company, with dominant market shares in voice, mobile, enterprise telecom, legacy voice, and fixed-line broadband resale. The former government monopoly, privatized in 1997, provides its services via its infrastructure assets such as a fixed-line network (data centers, exchanges, poles, ducts, pits and pipes, fiber network), a mobile network, and mobile towers. Its customers span retail, corporate, government, wholesale, and overseas segments. Telstra also provides the government-owned, last-mile fixed-line National Broadband Network with long-term access to its infrastructure, in return for recurring payments. Telstra also operates a leading telecom business in Papua New Guinea and surrounding South-Pacific countries.