Back in 2015, BT announced its intention to retire the UK’s aging telephony infrastructure, the PSTN (public switched telephone network), by 2025. This means that businesses still using traditional telephony services will have to undertake some significant changes in the coming years.

In this article, we’ll provide some context to explain the changes that are underway, explore why the decision has been taken to change the country’s telephony infrastructure, and introduce some of the solutions you can implement to keep your phone system operational beyond 2025.

What is The Public Switched Telephone Network?

The public switched telephone network is a framework of communications infrastructure designed primarily to support the transmission of voice data (phone calls). The system’s infrastructure continues to underpin the majority of telephone calls across the world today, with some elements of the infrastructure dating all the way back to the 1800s.

Contrary to popular belief, the PSTN isn’t an entirely analogue system, having incorporated many digital elements over the years to adapt to the digital revolution. The PSTN today contains a seamless blend of old and new technologies, including cellular networks, copper wires and fibre-optic cables.

The PSTN supports a number of communication standards and technologies, including VoIP (voice over internet protocol), ISDN (Integrated Services Digital Network) and ADSL (Asymmetric Digital Subscriber Line). These technologies facilitate the simultaneous transmission of voice calls and data (internet) across the vast and varied infrastructure of the PSTN.

What is ISDN?

ISDN is a telecommunications standard introduced in the 1980s, designed to enable the digital transmission of voice and data across the analogue elements of the public switched telephone network. While considered dated today, ISDN was revolutionary in its time, as it was one of the first technologies to permit the simultaneous transmission of voice and data across a single phone line.

If your business is still using an ISDN-based phone system, you’ll need to explore an alternative as a matter of urgency. Here’s why…

The PSTN is being Decommissioned, and with it, ISDN!

BT is in the process of replacing the aging PSTN network with full-fibre across the UK. The target date for the PSTN switch off has been set at December 2025, which means your business will need to be transitioned to a futureproof alternative long before then.

As the UK’s copper-based telecoms infrastructure is withdrawn, the telephony products designed to operate on it, such as ISDN, will soon stop working. In fact, BT suspended the sale of new ISDN lines earlier this year ahead of the switch off, in an effort to encourage customers to make the switch to an IP-based phone system.

Why Are These Changes Happening?

The traditional technologies are at breaking point. The traditional infrastructure of the PSTN was never designed with data transmission in mind, and even with the help of ISDN, it struggles to handle the sheer volume of data traffic that’s now imposed on it. Other reasons for the PSTN switch off include:

· Poor Flexibility. ISDN telephone lines are tied to fixed locations, offering both business and domestic consumers little flexibility. The traditional landline has fallen out of favour, as society has transitioned to mobile and digital solutions that are location independent.

· Aging Components. Some of the oldest parts of the PSTN are reaching the end of their service lives. Furthermore, the skills required to maintain and manage this infrastructure is becoming increasingly rare. Instead of performing a like-for-like replacement, the decision has been taken to replace outdated technology with a system that can cope with modern demands.

· Limited Data Speeds. The data-intensive nature of modern life means ISDN products often struggle to deliver the speeds today’s consumers and businesses demand. The growth of cloud-hosted software, for example, means businesses increasingly require modern, high-speed broadband to support their critical business activities.

· Lack of Integration. Today’s businesses expect their phone system to integrate seamlessly with other communication channels, as well as business applications like CRMs. ISDN-powered phone systems make it difficult, or even impossible, to implement the advanced functionality and integrations that modern business demand.

How Should I Prepare for the PSTN Switch Off?

The new, full-fibre network will require you to switch to a fully digital phone system. This means a system that uses internet protocol (IP), as opposed to ISDN.

Your next phone system must incorporate a communications technology called VoIP (voice over internet protocol). This is an umbrella term for a set of solutions that permit the transmission of voice and multimedia data across IP-based networks, or in other words, the internet.

Your business has a number of choices when it comes to operating a VoIP phone system. Let’s consider some of the most popular options, and discuss the benefits and drawbacks of each.

Cloud-Hosted VoIP

A Cloud-hosted VoIP system is a hassle-free, convenient choice for businesses looking to modernise their telephony. With a cloud-hosted system, the phone system software, and its underlying infrastructure, is hosted and managed on your behalf by the service provider. You simply pay a subscription fee, and access your phone system via any internet capable device.

Cloud-hosted VoIP provides cost-effective access to a feature-rich phone system, without the upfront costs that used to accompany traditional telephony investments. Enjoy a fully maintained and reliable phone system that can scale effortlessly alongside your business.

While hosted VoIP provides many great benefits, such systems are less customisable than the alternatives, as you don’t own or control the system, or the infrastructure on which it’s hosted.

On-Premises VoIP

With an on-premises VoIP phone system, your business acquires the VoIP equipment and software, and house the setup in your office or data centre. This option provides the same convenient user experience as a cloud-hosted VoIP system, but with greater control and customisation.

The downside of this option is the higher upfront costs involved in purchasing and installing the system, plus, your business remains responsible for its upkeep and security across its lifespan.

SIP Trunking

SIP trunking (Session initiation protocol trunking) is a subtype of VoIP technology, centred around a set of rules that govern how data transfer sessions are initiated and terminated between users across an IP-based network. SIP trunks essentially act as virtual phone lines, and are a good option if you’re intent on retaining your phone system through the PSTN switch off.

However, be sure to check that your existing phone system is IP-capable if SIP is the option you want to adopt.

Final Thoughts

With the transition to full-fibre telephony well underway across much of the country, it’s vital that your business looks into an IP-based phone system now, if you haven’t already. In Our next article, we’ll take a look at how the PSTN switch off could provide a great

opportunity for your business to modernise and streamline its communications infrastructure thanks to the unifying power and agility offered by cloud-hosted VoIP phone systems.

BCNS – Managed IT Support, Solutions and Consultancy for Devon Businesses

BCNS is a full-service IT provider, dedicated to bringing the best, tailored IT solutions to businesses across Devon. Our unrivalled knowledge and experience, combined with a commercially aware approach to business technology, ensures your business will benefit from solutions that drive value and empower growth. From best-in-class cyber security solutions to the cloud platforms and connectivity services you need to stay connected and productive, we’ll help you harness IT for strategic benefit across your business. Get in touch today for a friendly, no-obligation chat about your IT challenges. We’d love to hear from you.