http://zoecomm.net/
Originally, PBX (Private Branch Exchange) phone systems were devised to route internal telephone calls in an organization, only using the external telephone network (PSTN) for calls outside the organization. With the expansion of the internet and the emergence of digital VoIP (Voice-over IP) technology, the functions of your PBX can be provided by way of a hosted PBX solution where the service is outsourced to your data processing provider.