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.
Global Voice serves its clients through its wholesale Voice Over Internet Protocol ("VOIP") and backbone divisions. Global Voice allows carriers to combine the services to produce an end-to-end turn-key network for rapid deployment in their market. Global
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