Some telephones, depending on the brand and model, have the intercom function, which allows to begin communication by sending the signal. When the signal comes, the telephone set rings a signal different from the standard ring tone call. After that the telephone temporarily switches off from the telephone line and works as an intercom.
Asiasoft Software Technology Co.,Ltd (Asiasoft) was founded at the beginning of 2000, whose main business focuses in China. It owns multi-stock shared firms in Beijing, Shenyang and Hongkong.