Traditional Analog PBX Phone Systems: How Do They Work?

January 15, 2022
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A private branch exchange (PBX) is an office telephone system installed inside a company that connects users through local phone lines. It’s a telephone system that routes calls between users through local networks while allowing everyone to share a limited number of external phones. 

Originally, private branch exchanges were equipped with analog technology. Today’s PBXs are based on digital technology, with digital signals being transformed to analog for outgoing calls on the local loop, made possible by utilizing Plain Old Telephone Service (POTS) lines. Network switching systems are built into PBXs, which allows them to be connected to an enterprise’s digital PBX system if this is desired.

Let us look at how PBX phones and POTS function, their main purpose, and how they work.


What Is An Analog PBX Phone System_

What Is An Analog PBX Phone System?

PBX (private branch exchange) is a switching mechanism that links the phones and extensions inside a firm to one another as well as to external analog lines. Using this method, a large number of employees can share a limited number of external phone lines, potentially reducing costs.

An analog PBX system employs regular Plain Old Telephone Service (POTS) phones and copper wire for communication. They are dependable, provide excellent speech quality, and have all of the essential capabilities of a traditional house phone (such as hold, mute, redial, and speed dial), as well as the ability to transfer calls across extensions. They are also inexpensive. 

An analog PBX system maintains operational extensions even if the power goes off, and users will continue to be able to communicate. They are generally inexpensive since they are straightforward and offer few choices for expansion or improvement. 

On the other hand, they are more costly to maintain, set up, and update since they are less modular. To relocate an extension, for example, requires the rewiring of the punchboard by a qualified technician board.

Analog phone systems are associated with traditional landline telephone services. They link phones by sending speech signals over copper cables and via a series of physical switches to establish a connection between them.

Businesses that are still employing analog phone technology have often had their system in place for a long time. It is also common to see a Private Branch Exchange (PBX) system in operation in the majority of scenarios.

Read up on the parts of call flow here!

How Do Analog PBX Phone Systems Work

How Do Analog PBX Phone Systems Work?

The complexity of the system dictates the type of system that is used, whether it is a traditional PBX to which copper telephone landlines are connected, whether it allows a mix of analog and digital lines, whether it uses voice over IP (VoIP) hosted at the organization, or whether it is a cloud-based PBX system, among other things. Each of these is covered in further depth lower down the page.

Office telephones that use an analog PBX system rely on landline copper-based telephone lines that enter a business’s premises and are linked to a central office PBX box. 

These switch boxes are made up of telephony switches that allow calls to be distributed to different phones throughout an office while also allowing those phones to communicate with a limited number of outside lines, known as trunk lines, at the same time. 

An IP PBX, also known as an Internet Protocol PBX, is an office telephone system that sends calls using digital phone signals rather than traditional landlines. 

Because Ethernet cables may be used to link phones instead of traditional phone lines, there is no need to rewire the system. IT management service providers may also host IP PBX systems, which makes them more accessible.

Hosted systems demand monthly payments even though there are fewer hardware expenditures connected with their utilization on the part of the end customer. 

Smaller PBX systems, often known as virtual PBXs, provide hosted services but have fewer functions than larger PBX systems.

Further reading: How To Set Up A Customer Service Process Flow That Delights Your Ideal Customers 

On-Premise PBX

Landline phones and analog phones are identical terms. A PBX for landlines is used to connect calls between phones by transmitting voice signals over copper cables and then through a series of physical switches.

Businesses that still use analog phone technology have often had their system in place for many years. These businesses also often rely on Private Branch Exchange technology to communicate.

See the reasons why call flow is important here.

Modern PBX Systems

Modern PBXs are equipped with a variety of management capabilities that make communication inside enterprises easier and more effective, hence increasing productivity. 

Size and complexity vary, from large-scale corporate communication systems costing thousands of dollars and requiring extensive training to simple plans that may be hosted in the cloud for a small monthly price. The most basic functions of simple home-based PBX systems are available as an update to existing conventional phone lines.

Although the functions of a PBX might be complicated, the following are the most important ones:

  • In an organization, the use of more than one telephone line is permitted.
  • Telephone call management, including incoming and outgoing.
  • One phone line is divided into many internal lines, which are designated by three- or four-digit numbers called extensions, and calls are transferred to the internal line that is most suited for the caller.
  • Internal phone interactions are handled by the IT department.
  • VoIP (Voice over Internet Protocol) calling, which offers a variety of advantages and upgrades over the traditional telephone, the most notable of which is the cost savings, is becoming more popular.
  • Call recording, voicemail, and interactive voice response (IVR) systems provide a high-quality user interaction (interactive voice response).
  • Automated replies, which automatically lead consumers to the most relevant lines using voice menus, are becoming more popular.

Check out how to connect the phone to ethernet here!

Main Purpose Of PBX System

Main Purpose Of PBX System

A telephone switch station (PBX) is a device that enables users to make and receive phone calls across a telephone network. In its most basic form, it is comprised primarily of numerous office phone system branches, and it transfers connections to and from them, thus connecting phone lines.

A PBX is a device that allows businesses to connect all of their internal phones to a single external line. This allows them to lease just one phone line and have several individuals use it, with each person having a phone at the desk with each phone having a unique number. 

However, since it is based on the internal numbering system, the number does not have the same structure as a phone call. With a telephone system, it is only necessary to dial three-digit or four-digit numbers to connect with another phone on the network when using a private branch exchange (PBX).

Find out more about Automatic Call Distribution (ACD): What is it? How Does it Work?

A PBX system makes it simple and economical for businesses to utilize more than one phone line at the same time. A PBX, which manages both incoming and outgoing calls, makes it possible to divide a single phone line into numerous private lines, each of which is identifiable by an extension (usually assigned 3 or 4-digit numbers). 

Not only does this make it simple for customers to contact everyone in an office by dialing a single phone number, but it also allows the group to communicate internally without the need for many separate phone lines, which saves money. VoIP communication is enabled by PBX systems as well.

Learn more about how VoLTE works here!

Main Functions of PBX Systems

Functions of PBX Systems

PBX systems are responsible for four primary call processing tasks:

  • Connect the phone sets of two users by dialing their extension numbers.
  • Maintain connections for as long as the users need them to be maintained.
  • Disconnect a connection based on the demands of the user.
  • Provide information to the company for it to perform accounting and analytics functions.

Although it is realistic to assume that all PBX systems provide the capabilities outlined above, the vast majority of contemporary PBX systems additionally include a profusion of additional calling tools and capabilities (though each PBX may differ in which features they offer). 

Some of the most often offered PBX functions are as follows:

  • Call management is accomplished by the use of call blocking, call forwarding, call logging, call transfer, and call waiting for services.
  • Customers’ experiences are enhanced as a result of call recording, voicemail, IVR (Interactive Voice Response), and Direct Inward Dialing (DID) technology (Direct Inward Dialing). Custom greetings, welcome messages, and holding music are some of the additional customer-facing features that are often offered with a PBX system.
  • During business hours, conference calls and internal extensions are used to communicate among employees and departments.
  • Local connections enable customers to have local phone numbers in locations where they are not physically present, allowing them to operate ‘virtual offices’ from anywhere in the world.

Discover the Automated Answering Services: How Do They Work?

Conclusion - A reliable Intra office system


Large corporations must have PBX office phone systems to properly organize their telecommunications infrastructure. PBX infrastructure may be beneficial to small and mid-sized firms, but hosted solutions, rather than pricey on-premise systems, will often provide higher value to these organizations in the long run.

When a company relies on incoming or outgoing phone calls, moving to a PBX office phone system will result in quick and noticeable advantages. Digital PBX systems are great assets for businesses that rely on telephone-centric business operations because of their enhanced functionality and cheaper telephone expenses.

Companies wishing to incorporate comprehensive telephone customer service capabilities will need to do so via the use of a private branch exchange (PBX). It is important to have a system in place for efficiently routing calls during peak times so that consumers have an enjoyable customer service experience while also ensuring that internal calls are dealt with separately.

Hosting PBX options for small organizations need little to no upfront cost and managed suppliers provide a wide choice of customizable plans that are based on real service consumption. This technology is appealing to practically any company because of its ability to deliver enterprise-level telecommunications solutions in a scalable way.


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