| The term PBX refers to a Private Branch Exchange. | | | | Asterisk, an open source PBX, is touted as the world's |
| A PBX is sometimes called a telephone switch, | | | | most flexible and extensible telephone system. It |
| business telephone system or phone switching device. | | | | provides many features that compete with or exceed |
| The term PBX is synonymous with Electronic Private | | | | the power of proprietary telephone systems. In |
| Automated Branch Exchange (EPABX) and Private | | | | keeping with its open source concept, The Asterisk |
| Automated Branch Exchange (PABX). It is similar to a | | | | software is free and runs on relatively inexpensive |
| central office exchange but usually much smaller and | | | | Linux servers. |
| privately owned. A central off exchange can | | | | New technologies such as Voice over Internet |
| accommodate 10,000 subscribers. PBX systems are | | | | Protocol (VoIP) are blowing away the covers from |
| typically designed to accommodate from 10 to 10,000 | | | | traditionally proprietary devices. This technology takes |
| subscribers or extensions. A PBX is like a central | | | | analog audio signals and converts them into digital form |
| office exchange for a single building of cluster of | | | | for transmission. Transactions are much more efficient |
| buildings. A PBX can handle many phone lines into or | | | | since analog lines remain connected even during |
| out of a particular location. Most advanced PBXs can | | | | periods of no communication. VoIP packets are sent |
| facilitate both voice lines and data lines, route calls to | | | | and received whenever there is activity. The |
| other offices and to the public telephone network. With | | | | information packets are sent over any open rather |
| a PBX in place, each phone only needs an extension, | | | | than a dedicated line making communication much |
| not a phone number, and the PBX handles all calls | | | | more effective. |
| made between individuals within the company. | | | | Most companies can recognize huge savings using this |
| The primary intent of a PBX is to route incoming calls | | | | technology. The compression of the information and |
| to the appropriate extension within the office and to | | | | mode of delivery across multiple channels and routers |
| share a group of phone or "trunk" lines between | | | | makes packet switching more efficient, quicker and |
| extensions. When an outside call is required, an access | | | | less expensive. The volume of simultaneous |
| number is dialed (example "9") to access an outside | | | | communication can be significantly increased using |
| trunk line. The PBX then transfers the call to the phone | | | | packet switching over circuit switching. |
| company's Central Office. The telephone company | | | | The major manufacturers of PBX equipment have |
| then forwards the call to the desired number in the | | | | contributed millions to their research and development |
| outside world. | | | | budgets to produce solutions that allow customers to |
| Over time, PBXs have become far more | | | | efficiently migrate their traditional PBX. Some are |
| sophisticated. Many facilities and functions have been | | | | cleverly providing bridging solutions such as hybrid |
| added to create a centralized communication hub. | | | | PBXs that include traditional TDM and VoIP capabilities. |
| These services include automated attendant greetings, | | | | "We recently talked with 450 companies in North |
| recorded messages, interactive voice response, | | | | America about their voice infrastructure plans, and the |
| connection to voice mail, automated call distribution, call | | | | results clearly indicate a steady move to VoIP, which |
| forwarding, wireless services, conference calling and | | | | will put this market on a nice steady growth trajectory |
| many more. | | | | over the next few years.", said Matthias Machowinski, |
| A major advantage of a PBX is control over the | | | | directing analyst at Infonetics Research after the |
| numbers that can and cannot be dialed from within the | | | | release of their Q1 2006 report. |
| system. A properly configured PBX can restrict | | | | According to Infonetics Research, annual revenue in |
| access to certain costly numbers, such as directory | | | | the combined PBX market is forecast to grow to $11.4 |
| services or 900 numbers, to authorized personnel only. | | | | billion in 2009, driven by strong IP PBX sales worldwide |
| A major savings also results from the ability of the | | | | as more organizations move to voice over IP. |
| PBX to share a group of lines among many | | | | Between 2005 and 2009, IP PBX revenue is forecast |
| extensions. For example, an office with 100 extensions | | | | to jump 82% while TDM revenue plunges 88%. |
| can often be served by 10 to 15 lines. This results in | | | | According to a statement by In-Stat analyst Norm |
| huge savings from having to provide a line to every | | | | Bogen, "The IP PBX is revealing itself as more than a |
| phone in the company. | | | | simple one-for-one replacement vehicle for digital |
| Some of the most well known PBX manufacturers | | | | systems. With closer ties to data, this new vehicle is |
| with huge customer premise installations include | | | | influencing corporate power structures and will |
| Avaya, Nortel, NEC, Siemens and Alcatel. These | | | | ultimately have even more far-reaching effects on |
| manufacturers have dominated the telecom space for | | | | how business is done around the globe." |
| many years. However, a new crop of IP PBX | | | | Communication managers need to wade through |
| systems is entering the market packed with similar or | | | | organizational challenges including infrastructure, |
| enhanced features at much less cost. In fact, these | | | | financial and educational. The PBX is transforming itself |
| new communication servers can reside on a computer | | | | to meet these ever changing needs. |
| processor running low cost operating systems. | | | | |