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ISDN SWITCH OFF

Prepare Your Business Ahead Of The ISDN Switch Off

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In 2015, BT announced that they would be turning off their PSTN (Public Switch Telephone Network) and ISDN (Integrated Service Digital Network) by 2025. However, this deadline has now been pushed back to 2027.

What Is A PSTN Network?

PSTN (Public Switched Telephone Network) is the original analogue telephone system, built on a network of copper wires. It enables the transmission of voice and limited data by converting sound into electrical signals that travel over these copper lines. This legacy infrastructure has been the foundation of traditional landline telephony and early broadband connections for decades.

What Is An ISDN Network?

ISDN (Integrated Services Digital Network) was later introduced as a significant upgrade to the PSTN. Designed to transmit both voice and data digitally over the same physical copper lines, ISDN improved speed, clarity, and reliability. Its digital architecture allowed for faster data transmission, multiple simultaneous connections, and enhanced functionality compared to the purely analogue PSTN system.
Phone call, spa and woman at reception with tablet checking website for online booking schedule.

So, after the ISDN switch off, what's coming in to replace them?

The replacement for both systems is VoIP – Voice Over Internet Protocol. VoIP enables voice calls to be made over an internet connection. This means that voice calls can be made over a range of different devices. The VoIP system requires a broadband connection; this can be through a cable modem, a DSL or a local area network.

 Through the new system, VoIP will allow you to convert your voice into a digital signal that travels over the internet. You will be able to make direct calls from a laptop or computer, a VoIP phone, or a traditional phone using a VoIP adapter.

Switch to VoIP

How will the ISDN switch-off affect your business?

Switching from the legacy ISDN/PSTN network to VoIP (Voice over Internet Protocol) isn’t just about changing how you make phone calls—it can affect a wide range of your organisation’s operations. Systems such as CCTV, alarm lines, door entry systems, lift emergency phones, payment terminals, and even some broadband connections may currently rely on PSTN infrastructure.

Transitioning to VoIP requires a thorough review of all systems connected to the analogue network to ensure they are compatible with modern digital alternatives. Without proper planning, businesses risk unexpected service interruptions or operational delays.

At BSG Telecom, we’re here to guide you through every step. Our team will assess your current setup, recommend tailored digital solutions, and manage the entire migration process—making your switch to VoIP smooth, secure, and stress-free.

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