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    August 24, 2023

    What is a PBX?

    PBX Phone System Hardware

    The modern business world has plenty of exciting technology. This includes cloud-based communication systems, meeting devices that can be joined with one tap, and collaboration spaces that look more like the bridge of the starship Enterprise than a conference room. More businesses are also looking to integrate AI and AR into their technology environments. 

    Still, among all this modernization, many organizations rely on much older technology. Law firms still have fax machines, hospitals still use pagers, and most enterprises still have PBX (public branch exchange) systems. For as long as these systems are still in use, they need to be supported without causing friction or costing too much.  

    This is Continuant’s guide to PBX systems. 

    The Basics of a PBX System 

    PBX systems are telecommunication systems that allow users to connect to the PSTN (Public Switched Telephone Network) through different hardware components. These systems relay calls to the outside world and come with a wide variety of advanced features for both inbound and outbound calls.  

    Setting up a PBX system can be tricky. It requires a team of telecom experts, which some IT teams may not have. The system also takes up a lot of space, meaning most of its hardware will have to stay in a closet or a dedicated server room.  

    Despite this, many organizations still have a PBX. To understand why, and how these organizations may benefit from it, look no further than the traditional phone system.

    POTS with PBX 

    POTS stands for Plain Old Telephone System. This system includes any analog phones, such as desk phones and door phones, and the twisted wires that connect them to the local phone company. It’s basic, reliable, sometimes mandated by law, and hasn’t changed much in well over 100 years. 

    A POTS is important for connecting to the Publicly Switched Telephone Network (PSTN), but it can be expensive. 100 phone lines can cost a business thousands of dollars a month. A PBX helps by allowing its users to run an internal phone system and use fewer lines. It also makes it easy to set up voicemail, auto attendants, and recorded messages. 

    PBX systems provide tremendous value to organizations with older phone systems, and with the onset of digital and cloud-based PBXs, they can still help modern businesses.  

    The Benefits of a PBX 

    A PBX system allows businesses to: 

    • Manage and complete calls on a specific, pre-programmed network while placing restrictions on international calling to reduce costs. 
    • Transfer calls between users reliably through hot and cold transfers. 
    • Customize greetings with recorded messages, hold music, and even alerts for customers. 
    • Create a call center to better assist sales and customer service teams. The number of callers may depend on the type of PBX, with cloud-based systems being able to queue and distribute much more than On-Premises. 
    • Connect multiple locations to a single phone system.

    Types of PBX Systems 

    There are three types of PBX systems to choose from: a hosted cloud PBX, a traditional on-premises PBX, and a hybrid solution that combines both. 

    Hosted PBX 

    A hosted or cloud PBX is a cost-effective, flexible solution for businesses of all sizes. It allows its users to manage phones throughout the entire organization through an online portal on their web browser. It comes with all the features of a standard PBX such as call recording, call routing, voicemail transcripts, auto attendants, hold music, and more -- without the hardware. 

    Instead of keeping large servers in a closet, hosted PBX servers are taken care of by service providers. The burden on IT teams is massively reduced compared to an on-premises system. This type of PBX can also be integrated with CRM software, VoIP apps, and UC (Unified Communications) solutions. It can also route calls to personal devices as well as company-owned phones. 

    On-Premises PBX 

    Often called traditional or legacy PBXs, this type of PBX systems refers to the servers locked in closets mentioned earlier. Given all the advantages of a cloud-based system, it’s hard to build a case for sticking with an on-premises option. There are, however, some things worth considering before going scorched earth on the server room. 

    An on-premises PBX has no dependency on an internet connection. This can be valuable in places where internet connection is unstable, and even necessary for certain organizations’ E911 requirements. 

     There’s also an argument to be made that this system is more secure since it can’t be hacked. Unfortunately, it’s still vulnerable to dangers such as the 90# Telephone Scam 

    Most of the time, an on-premises PBX is too inflexible or cost-prohibitive for a modern business. Still, there are cases when removing an existing on-premises PBX, what we sometimes call “rip and replace,” is more costly than keeping it.  

    Hybrid PBX 

    A hybrid PBX is the perfect solution for businesses who want to or must keep their on-premises PBX. By connecting the PBX to a SIP (Session Initiation Protocol) trunk, its users can use VoIP technology and UC solutions like Cisco Webex and Microsoft Teams alongside their standard PBX capabilities. 

    This system does still come with the downsides of an on-premises PBX, such as upfront setup, server space, and ongoing IT maintenance costs. However, it adds scalability and flexibility for a system, and can often be more cost-effective than a complete overhaul. 

    Image Diagram - Continuant Connect Hybrid Calling Solution

    While Microsoft Teams is used in this diagram, services like Cisco Webex and Zoom can also be used.

    The Right PBX and Maintenance 

    The right PBX system will vary organization by organization.  

    For example, a hybrid solution could be a perfect fit for a business relying on a legacy PBX that also needs more advanced features. Conversely, a hosted PBX is the best choice for businesses that have no preexisting phone system. Either solution can add near-infinite scalability and reduce costs. 

    Regardless of the solution type, maintenance is an important thing to consider, especially for hybrid systems. A PBX needs to be constantly monitored and supported to keep its users connected.  

    Many legacy PBX users have struggled to get the maintenance they need from their original providers. They can often be hard to reach, and occasionally put pressure on their users to upgrade their systems when they don’t need to.  

    Hosted PBX users don’t have this same problem, but their system is very dependent on proper design and deployment. Implementing a cloud PBX isn’t always as simple as flipping a switch. If done improperly, its users won’t be able to make full use of its features.  

    Businesses that use either system can circumvent these issues with the help of a partner. Certain companies, like Continuant, can provide a third-party maintenance option for legacy PBXs. They can also help design, deploy, and manage a cloud-based solution by setting up SIP trunks, ensuring calls are properly routed, and integrating CRM, VoIP, and UC software. 


    The PBX isn’t going anywhere. A hosted PBX can still provide more than enough value to modern organizations. As for the legacy PBX, companies that still use them have invested too much to simply get rid of them. For these especially, it’s important to take the right steps to keep them running at peak efficiency. 

    Continuant can help your organization get the most out of its legacy PBX, and design and deploy a cloud-based solution when you’re ready to make the transition. Are you considering different options for your PBX system? Connect with us today.

    Scott Graham

    Scott Graham was one of the four original employees of Continuant’s predecessor company, Telecom Labs Inc. (TLI), joining in 1996 as Operations Manager. Prior to joining TLI, Graham was an industrial engineer at Cascade Corporation in Portland, Oregon; and also worked for Frametech Inc. of Honolulu as an industrial...

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