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.
VoIP Gate offers services to companies and private persons that running their own VoIP solution and looking for an gateway solution for incoming and outgoing calls.
Read more