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.
Installation and repair of VoIP business phone systems. Superior support service so you get all the advantages of an internet based phone system without the hassle. Quality equipment installed to ensure optimal performance.