The prosperity of any organization depends on how well it communicates with its clients or how incessantly it caters to their needs or attends troubleshooting. As a catalyst to this process came the concept of PBX or PRIVATE BRANCH EXCHANGE. This allows one dialing number to be connected to several telephone units. In this way the calls of several callers on a single number can be attended.
Also another catalyst would be the VOIP or VOICE over INTERNET PROTOCOL. VOIP is a methodology and group of technologies for the delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet.