Public Swtiched Telephone Network

The Public Switched Telephone Network (PSTN) refers to the traditional network of copper wires, fiber-optic cables, cellular networks, and switching centers that has been used for decades to provide voice communication services worldwide. Often simply called the "landline," the PSTN forms the backbone of global telephony, enabling people to make calls across town or across the world.

But as digital communication technologies evolve, so too does the role of the PSTN, especially in light of major shutdowns and the rise of internet-based communication systems. 

How does the Public Switched Telephone Network (PSTN) work?

The PSTN is a circuit-switched network, meaning that it establishes a dedicated communication path between two endpoints during a call. Here's a simplified look at how it works:

1. Call Initiation: You pick up your phone and dial a number.

2. Call Routing: The signal travels through a network of local exchanges and switching centers.

3. Circuit Establishment: A physical or virtual circuit is established between your device and the recipient’s.

4. Voice Transmission: Your voice is transmitted in real time over the circuit.

5. Call Termination: Once the call ends, the circuit is released for use by others.

The reliability and simplicity of PSTN made it the global standard for voice communication for more than a century. 

PSTN vs. VoIP: What’s the difference?

With the rise of Voice over Internet Protocol (VoIP) services, the limitations of PSTN have become more evident. Here’s how they compare: 

Why is PSTN Being Phased Out?

Due to aging infrastructure, high maintenance costs, and the demand for more flexible communication options, many telecom providers around the world are gradually retiring PSTN services. In countries like Australia, the UK, and the US, transitions to all-IP networks are already underway.

This means services that rely on landline technology, like traditional fax machines or alarm systems, may need to switch to digital alternatives. For example, cloud fax solutions like Notifyre allow users to send and receive faxes with top-notch security without relying on PSTN. 

PSTN in the Modern World

Even though PSTN is being replaced in many regions, its legacy is undeniable. It laid the foundation for today’s digital communication and still supports millions of phone calls daily.

However, the shift toward digital-first communication means businesses and individuals need to start adopting IP-based services that offer greater reliability, scalability, and lower operating costs.

As the PSTN phase-out continues, now is the time to future-proof your communication systems. Whether you're still using traditional methods or exploring digital alternatives, transitioning to internet-based solutions, such as online fax machines, can help your business support remote teams and stay operational.