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.
Packet Shaper Technologies is a leading broadband products and service company in the Asia-Pacific region. Headquartered in New Delhi, India, Packet Shaper Technologies has marketing alliances in Singapore and USA.