21Vianet Group, Inc. provides carrier-neutral Internet data center services in the People's Republic of China. The company provides hosting and related services to house servers and networking equipment in its data centers, and connects them through a data transmission network; and other hosting related value-added services. Its hosting and related services include managed hosting services that offer data center space to house customers' servers and networking equipment and provide tailored server administration services; interconnectivity services, which allow customers to connect their servers with Internet backbones in China and other networks through the company's border gateway protocol network or single-line, dual-line, or multiple-line network; content delivery network services; cloud infrastructure services; and value-added services comprising firewall services, server load balancing, data backup and recovery, data center management, server management, and backup server services. The company also provides traffic charts and analysis, gateway monitoring for servers, domain name system setup, defense mechanism against distributed denial of service attacks, basic setting of switches and routers, and virus protections. In addition, it offers managed network services, which allow customers to transmit data across the Internet through its hosting area network and data transmission network, which connects the servers housed in its data centers; and route optimization services. As of December 31, 2012, the company operated 10 self-built and 71 partnered data centers located in 42 cities in China with approximately 11,900 cabinets. Its customers include Internet companies, blue-chip enterprises, government entities, and small- to mid-sized enterprises. The company was founded in 1999 and is headquartered in Beijing, the People's Republic of China.