The VoIP PBX

The Voice-Over-Internet Protocol (VoIP) has shaken the telecoms world. No longer is a protocol that is limited to theory and laboratories and white lab coat audiences, VoIP is poised to radically change the face of how we do communications and challenge the traditional switched telephone networks.

VoIP addresses the use of packet-switched networks, such as the Internet, to deliver voice. Contrast that to the traditional time-division multiplexed (TDM) network which we have all been using for years. The meteoric growth of the Internet has brought Internet access to many areas in the world that don’t even have an existing telephone service. For people living in these areas, VoIP represents their link to the rest of the world.

A private branch exchange, or PBX, is an older telecoms concept. A PBX is a small telephone exchange system that serves a single office or company. Think of it as a smaller version of the large-scale telephone system we’re all familiar with. The PBX manages all calls within an organization and connects it to the larger public switched telephone network (PSTN). For years people have deployed PBXes in offices to serve as a small switching station that allows all employees to share limited PSTN phone connections. Traditional PBXes have also been used to provide voice menus, call transfer, call waiting, and call conferencing.

The modern IT environment puts more and more demands on communications. VoIP PBXes have more features and offer more functionality than traditional analog PBXes. Aside from the usual PBX functions, they can do much more and are more programmable. Also, because VoIP PBXes operate in the digital domain, a regular personal computer can be put to use as a PBX. Using modern VoIP PBX switch software such as Asterisk users can, for instance, program the system to know holidays and to inform callers when an office is closed. More advanced applications of a digital VoIP PBX include voice mail and encrypted communications. But perhaps the most important benefit of using a VoIP PBX is that all calls, no matter their origins, travel through the global Internet. This breaks down the barriers of distance; long distance calls can now essentially be considered local calls in terms of costing and distance. The possibilities that VoIP and VoIP PBXes present are practically limitless.

People and businesses looking to integrate a VoIP PBX into their existing infrastructure, or even migrate an existing analog infrastructure to VoIP, have many choices to choose from. On the high end of the scale, companies such as Avaya, Cisco, and Nortel provide expensive but high quality VoIP systems and hardware. On the midrange to lower end of the scale, choices are more varied, but probably the most promising midrange VoIP provider is Digium. Digium offers very affordable preconfigured VoIP PBXes that run the open source Asterisk software.

CoralRock’s Starfish VoIPBox is another product worth checking out.