Private Branch Exchange (PBX)

Our Linux-based Private Branch eXchange (also called PBX or Private Business eXchange) is a very powerful telephone exchange. Functionally, the PBX performs three main duties:
 

• Establishing connections (circuits) between the telephone sets of two users. (e.g. mapping a dialled number to a physical phone, ensuring the phone isn't already busy)
• Maintaining such connections as long as the users require them. (i.e. channeling voice signals between the users)
• Providing information for accounting purposes (e.g. metering calls) 

In addition to these basic functions, PBXs offer many other capabilities, with different manufacturers providing different features in an effort to differentiate their products. Here is a short list of common capabilities (note that each manufacturer may have a different name for each capability):

• Call transfer
• Direct Inward Dialing
• Customised Abbreviated dialing (Speed Dialing)
• Voice mail
• Follow-me
• Call forwarding on absence
• Call forwarding on busy
• Music on hold
• Automatic ring back
• Night service
• Call distribution (ACD, fixed sequences, ...)
• Call waiting
• Call pick-up
• Call park
• Call conferencing
• Custom greetings
• Shared message boxes (where a department can have a shared voicemail box)
• Automated directory services (where callers can be routed to a given employee by keying or speaking the letters of the employee's name)
• Call accounting