Network PBX technology can be divided roughly into four parts:
- A trunk interface that connects the system to the telephone service provider
- A station interface that telephone handsets plug into
- The switching fabric that connects the trunk to the outside line
- A call control database that handles all the normal features such as call forwarding, do-not-disturb functions, and other call control rules
Network PBX systems, which are most often sold and installed by systems integrators, consist of a server connected to telephone handsets and incoming telephone trunk lines through a specialized interface device. Calls are managed at the desktop level, typically using a Windows application. These systems, which cost approximately $30,000 to $60,000, are intended for medium and large business applications with hundreds or thousands of users.
A second category of products, often billed as un-PBX or PC PBX, are less expensive systems for small-office environments. These systems generally cost a few thousand dollars and add cards and software to an existing server. They typically lack scalability and are best for single-site installations such as branch offices with a couple of dozen to a hundred users. However, they still offer the same advantages of the larger systems and are easy to manage and maintain.
