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.
Our company goals are straightforward: Offer our customers a platform to exchange voice traffic that is high quality, convenient, easy to manage, and inexpensive to operate.