The telephone application installed on the network depends on the selected telecom service provider. At present, Internet service providers in China include China Mobile, China Unicom, China Telecom, China Tietong and China Satcom. These six companies are the largest and most powerful in communication and ground network, but each has its own emphasis.
Telecom: 10000
China Mobile: 10086
China Unicom: 100 10
China Tietong: 10050
China Satcom: 10070