VoIP Services VoIP is a revolutionary telephony service, suitable for both businesses and residential users. VoIP delivers phone calls over a broadband connection but behaves like a traditional telephone service, reducing the cost of calling. This service provides free on-net calls to other FullDuplex customers and reduced call rates to national, international and mobile destinations. What is VoIP? VoIP (Voice Over Internet Protocol) is the technology used for making telephone calls over the Internet. Using a VoIP Service means that you can make cheap calls anywhere through a fast Internet connection. To use a VoIP service, you would typically use a broadband connection together with some special equipment. This equipment could be either a personal computer installed with relevant software, or a traditional telephone handset with an adaptor (ATA) that plugs into the broadband connection, or a wireless device with suitable software installed on it.