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Your Guide To PBX Systems

3 févr. 2020

A PBX, or private branch exchange, is a private telephone network that is commonly used by companies and organisations for internal communication. There are many features and benefits to establishing a PBX system that will be explained below.


What does a PBX system do?

A PBX system is used to provide telephony services within an organisation. This means providing phone numbers for different devices, as well as quick dial internal calling features, call forwarding, call transfer, call queueing, auto-attendants, voicemail, and plenty more. PBX systems can operate over VoIP (Voice Over Internal Protocol) or analogue phone lines. PBX phone systems allow an incoming phone line to be split into multiple phone lines and provide free calls within the network, as well as the ability to make and receive external phone calls.


Why do companies use PBX?

There are multiple reasons for a company to use a PBX network. For one, they are a very useful communication tool for both internal and external communication. Importantly, these calls are free for internal calls. What’s more, PBX systems support many additional features likely to be of use to a company.


As well as supporting communication within an organisation, PBX systems make it much easier to manage and handle incoming calls from external sources. Incoming calls can be handled in several different ways depending on your organisation’s preferences. Features such as auto-attendants and IVR (Interactive Voice Response) help callers to be routed to different extensions depending on their needs. This means a caller does not have to know the specific phone number or extension of the person they wish to contact - one number can serve many different purposes. Of course, this doesn’t preclude using different phone numbers for different departments or individuals within a PBX system if desired.


What is the difference between VoIP and PBX?

There are a few differences between VoIP and PBX but the main difference is that PBX technology functions over a traditional phone landline using either analogue or digital signals, whereas VoIP functions over the Internet using exclusively digital signals. Both are means of sending and receiving calls and neither will likely make a difference to the end customer experience. The main place the differences are felt is in the setup and maintenance of the respective networks.


A PBX phone system typically requires all hardware and networking infrastructure to be bought and installed on-premises. This can lead to higher initial installation, setup, and maintenance costs but it also allows businesses to retain exclusive control of their internal communications network. This is particularly good for businesses that deal with private or sensitive that cannot be shared with a third party.


VoIP services meanwhile have comparatively low hardware costs - most smartphones and Internet-enabled telephones will be compatible with a VoIP system without any special hardware or configuration required. In addition to standard telephones, VoIP systems can also function on smartphones, laptops and desktop computers. Most of the networking infrastructure is handled by the VoIP service provider, so there is little ongoing maintenance required with a VoIP system.


Large businesses may find the extra privacy and data protection offered by a PBX system to be worth the additional cost, whereas for a small business, the upfront expenses and maintenance costs may make a VoIP system more attractive. 


What features do PBX systems support?

PBX systems are capable of much more than simply sending and receiving calls. As with any organization regularly dealing with both internal and external calls, there are many additional quality of life features that make handling and managing high volumes of calls a much easier and smoother process.


Call trunking

Call trunking is a system that merges data from multiple calls into a single set of packets. Essentially this allows one phone line to support multiple phone numbers and simultaneous phone calls, which is important for things like call centres or customer support lines.



It’s easy to configure both blocklists and allowlists as part of a wider PBX network tree. As an example, this can be used to restrict or permit who is capable of making or receiving international calls, which can help businesses to control costs associated with these calls in a programmable way.


Auto-attendants and queue system

PBX systems support both auto-attendants and queueing systems. This means that customers and outside users can call in to a number and then the auto-attendant can help to filter them to the appropriate department/extension. If there is not anyone available to take the call, then the user can be held in a queueing system while they wait. This can naturally be pre-configured to play any sort of message or music that the company desires.


Interactive Voice Response

Interactive voice response (IVR) is similar to an auto-attendant but it allows users to simply say what they need rather than having to press a particular number on their keypad. These systems offer a much better user experience compared to more traditional auto-attendants and they can be fully customised to handle the particular needs of your business.


Call management features

In addition to the above-listed features, PBX systems also support all of the standard call management features that you would come to expect from a phone system, such as call forwarding, call transferring, call logging and voicemail. All of these combine to make it easy for team members to help tackle incoming calls.


Virtual PBX

Virtual PBX, also known as Hosted PBX or Cloud PBX, sits somewhere in between unified communications as a service and on-premises PBX. When something is provided as a service, the networking and maintenance of that service are provided by another company for a cost. In exchange, you pay a monthly or annual cost to have the service provided to you. A virtual or hosted PBX is a PBX system that delivers PBX functionality as a service. In this case, the hardware, installation, and maintenance costs are taken care of for you. They are not as flexible or customisable as an on-premises PBX but they can be a good middle ground for businesses that feel they want the functionality of a PBX system but without dealing with the associated costs.