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

web conferencing

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:

  • Cut Costs - Many automated features will reduce staffing requirements. For example, an automated attendant reduces the time requirements for staff answering telephone calls and routing outside callers to the right line. IP based phone systems also make disaster recovery capability easier and far less costly.
  • Flexibility - A virtual PABX can be deployed on-site, or hosted in the cloud. This provides the opportunity to find the most cost effective solution.
  • Higher Efficiency - Voicemail, for example, can be sent as an audible file by emails. This means less time spent on checking emails, and reduces the possibility of getting messages late.
  • Provide Better Customer Service - Studies have found that customers are happiest when they can choose between self-serve automation and in-person service. Auto attendants with the option to call the operator provide a good example. Call forwarding rules can ensure that incoming calls reach the right place at any time of day.

Why use 3CX as your PABX system?

3CX is a full-featured and advanced PABX that offers businesses clear advantages:

  • Low Costs - 3CX offers annual flat rate pricing based on simultaneous calls with no additional costs. This usually translates to much lower costs compared to a traditional telephone company or even VoIP service providers.
  • Hardware & Setup - 3CX integrates with existing telephone lines, server infrastructure and SIP phones. Easy setup means training costs for PABX technicians.
  • Facilitate Remote Work - Full-featured mobile apps and web phones allow users to connect to their office extension, receive phone calls or make outgoing calls from anywhere.
  • Unified Communications System - 3CX includes video conferencing, faxing and live website chat.
  • Advanced Features - 3CX PRO offers full call center features, such as wallboard and advanced queue strategies.

  • Build Voice Apps - Easily automate call flows with the 3CX call flow designer

Further reading