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.
Aianna and AiannaOne is a Global provider of telephony services, that was established at the vision of one man who was tired of the lack of service and quality that carriers were giving to their clients in the telecommunications industry.