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.
DOW Networks is a next-generation telecommunications service and solutions provider focused on meeting the international inbound and blended calling needs of call centers, hotels, and international enterprises in various markets worldwide.