With the BT ISDN switch off currently in motion in and around the UK, we thought we would take a little look at why this is happening, how it might affect your business and what your options are once the big red button is pressed.

Shall we?

#1: What is an ISDN line?

Integrated Services Digital Network (ISDN) is a set of communication standards for simultaneous digital transmission of voice, video, and data over the traditional circuits of the public switched telephone network (PSTN).

If, like me, you do not speak fluent jargon, then this is when your standard phone line is utilised to send both voice and data over a single line. Remember when you could only use the internet so if nobody else was on the home phone? Well, an ISDN line lets you surf the web unto your heart’s content whilst also allowing for mum’s evening call with nan to go on uninterrupted. It was simply serendipitous.

The business application of this technology, of course, was far greater, and at its peak, there were over 1.3 billion lines in-use around the world.

#2: Why is ISDN being switched off?

Much like those of us who remember the Internet vs. home phone dilemma, ISDN is getting on a bit.

From the late 80s to early 00s, ISDN was the crème-de-la-crème of fast digital connections, allowing internet access and data transfer at 128mbps – the fastest possible at the time. However, the truth is that this is now a 30-year-old technology running on 100-year-old infrastructure and is showing its age. The PSTN network was launched in the 1800s and is still being used today, just let that sink in.

The reality is that the last couple of decades has seen BT invest heavily in much better technologies such as Ethernet & SIP. These faster, safer, and more reliable alternatives essentially render ISDN obsolete, making it no longer strategic or financial sense to keep updating outdated systems.

#3: When is the ISDN switch off happening?

ISDN and PSTN are both set to be switched off by BT in 2025, with no new orders being taken after 2023. Some areas, such as Salisbury, are already in the process of being switched off as BT trial the process. More areas are expected to follow over the next 12-months. You can download the list of areas being switched off in 2021 here.

You may be wondering why it is taking 5 years to pull the plug indefinitely? This is because a) there are still millions of ISDN lines being used in the UK currently and they all need time to migrate and b) BT needs to ensure that there is alternative technology available in all those areas. For many businesses, ISDN is still the best service they can get.

#4: What products will be in impacted?

The PSTN network currently supports many common business connectivity products such as ADSL, FTTC & traditional PBX’s. As the switch off unfolds, you should speak to your provider to seek alternative solutions.

#5: What should you do?

If you are one of the millions of customers utilising ISDN, you have until 2025 to review your options and arrange a solution. If your current ISDN phone contract or service is up for renewal soon, now is the right time to start exploring the option of switching to VoIP and SIP technologies.

VoIP (Voice over Internet IP) and SIP (Session Initiation Protocol do not use traditional landlines to make connections, but instead enables both voice and video calls on a global level using your internet connection. This makes the service both cheaper, and by far easier to set-up as there are no physical lines to be installed.

Many businesses (around 40%) have already upgraded from ISDN. There are many benefits aside of the price, features and easy maintenance) so please do explore all your options before making an informed decision.

Thank you for reading! If we have not covered something that you would like to know regarding the ISDN switch off, please contact us online here or by phone on 0800 1 959 959 and we will offer some assistance. Want more information digitally? You can download the list of UK cities that are set to be switched off in 2021 here.