Difference between PABX and PBX
The difference between a PBX and PABX is quite simple. A PBX is a “ private branch exchange,” while a PABX is a “ private automatic branch exchange.” The only difference is the word “automatic.”
The difference goes back to the history of telephone systems. Originally, a PBX required switchboard operators to connect internal callers to other lines. Operators did this manually by literally unplugging lines and plugging them into the right extension.
The PBX was already an advancement over the original “plain old telephone system” (POTS) which required individual lines for each desk in an office. To dial another desk was just like making an outbound call. Outside callers had to know which number to call directly. No call transfer capabilities, conference calls or voicemail. The ability to connect two office extensions, transfer a caller to a colleague or share a single access number for a business was already a big deal, even if it was manual.
When electronic switching became available, the automatic telephone system was born - the PABX. Users were able to dial an extension number to make an internal call without the need for an operator. It would be rare to find telephone systems without this feature. So, the reality is that every PBX today is actually a PABX.
The question is: Is there any real difference in the terms?
Many people observe that since non-automatic PBXs really don’t exist anymore, the terms are interchangeable. While this is true, in practice it’s good for businesses to keep paying attention to new automatic features available for phone systems.
IP communications
PABXs have already evolved to use IP (internet protocol) communications. With internet service available in most places, a PABX now works over a LAN (local area network) or internet connection. This is often called an IP PBX.
These systems connect a business's SIP phones (session initiation protocol) and VoIP phones (voice over IP). It also connects the internal system to the public network, or public switched telephone network (PSTN), which basically means connecting to outside lines. Businesses can now use their office extension on a web browser or a personal cell phone.
The IP PABX has opened the door to further automation. For example, businesses can set up automatic call forwarding rules based on time of day or specific extensions. Callers can now tell an auto-attendant what extension they want or what they’re looking for verbally. Auto attendants can recognize different languages.
The system can alert other users when the extension a caller wants is busy (BLF - “busy lamp field”). Phone systems can connect with calendars and automatically set a user's availability accordingly. Even caller ID, which is now a standard feature, is possible as a result of automation.
While the difference between a PABX and PBX system may no longer be relevant, automation has continued to grow, faster than ever.
What are the advantages to automating your PABX?
Business telephone systems will do well to continue paying attention to new automation features. Some advantages include:
Why use 3CX as your PABX system?
3CX is a full-featured and advanced PABX that offers businesses clear advantages: