The BT ISDN & PSTN Switch Off 2025: How Will It Affect Your Business?

A detailed guide on how the BT ISDN switch off in 2025 will affect your business
16th November 2021

In 2015, BT announced that it would cease taking ISDN orders in 2020 with the view of switching off its ISDN and PSTN network entirely in 2025 – a change that is only four years away. This makes now the perfect time to find out what ISDN and PSTN are, why they are being replaced and how the BT switch off in 2025 will impact your business in the years to come.

What are ISDN and PSTN?

ISDN stands for Integrated Services Digital Network, which is a set of communication standards. They use digital transmission to make phone calls, video calls, transmit data and other network services over the circuits of the traditional PSTN. Introduced by BT in 1986,  ISDN replaced old fashioned landlines with digital ones, whilst adding new features that weren’t available with the old telephone system. 

PSTN is the Public Switched Telephone Network, which has operated since the 1800s. It’s the network that we have used for decades for our land-based telecommunications. Just as many other areas of our daily lives are undergoing change due to advances in technology, it is time for that traditional technology to be updated so that it can match up with the digital landscape and requirements of business today. PSTN is now considered a legacy network and so the switch off is being planned for a 2025 completion.

Why are ISDN and PSTN being switched off?

According to BT, ISDN and PSTN are being switched off to “embrace the boundless possibilities of digital”. In other words, it is so they can focus on a more progressive technology that will better meet the demands of businesses and homes in the future. 

Whilst the ISDN and PSTN infrastructure has been significantly improved since it was first launched in the 1980s, the core of it remains unchanged (albeit with a few upgrades here and there). BT has therefore decided that it is time for a significant change.

What are ISDN and PSTN being replaced with?

As ISDN and PSTN cease service, BT is replacing them with more modern and progressive technology. For quite some time, BT has been planning to move all of its voice network to Voice over Internet Protocol (VoIP), a data non geographic number (NGN) service supplied to end-users, which brings lots of benefits for business over PSTN and ISDN. These benefits include:

  • New VoIP lines that are much quicker to provision
  • Line rentals can be reduced as fewer physical lines are required
  • VoIP is scalable and flexible

VoIP is the modern communication standard, defining the modern world and communication today. It allows businesses to make the most of modern internet based communication and technologies, whilst reducing costs, improving call quality and preparing for the future.

Before the switch off vs. after the switch off

In the case of typical broadband services, they are reliant on the provision of a traditional fixed/voice telephone line. This means that separate voice and broadband services are installed to premises to enable data connectivity. However, when the voice line has ceased service, the broadband connectivity is also lost.

With the move to new technologies and Next Generation Services connections like SoGEA (Single order Generic Ethernet Access) and FTTP (Fibre To The Premise) no longer need the base layer of a WLR/voice connection. 

If you are thinking business then WLR (Wholesale Line Rental) is the recognised terminology for a BT basic business landline that is provided by a BT partner. These WLR lines are no different to analogue lines traditionally installed into residential premises. 

Put simply, after the switch off all simple data  and voice services will be available using IP (Internet Protocols).

What does the ISDN switch off mean?

This means that you will have to upgrade or migrate your existing telephone system to either hosted voice or VoIP (Voice over Internet Protocol) which uses internet lines to make your phone calls, rather than traditional copper. 

Much the same as it is with how we use our mobiles, the switch to business apps and calls over WiFi will provide you with more features and greater flexibility. There is also less of a need for physical hardware environments, thereby reducing the average cost of infrastructure services and support.

What should businesses do to prepare for the ISDN switch-off?

If your business is one of BT’s 2 million ISDN customers, you have until the 2025 switch off to review your various options and transfer before the network is switched off entirely.

If your current ISDN phone contract is up for renewal shortly, now is the ideal time to begin exploring the option of changing to VoIP and SIP technologies.

How will the ISDN switch off affect your business?

The PSTN network, which ISDN operates on, will be ceased in 2025, meaning all businesses will need to move away from fixed-line services such as analogue or ISDN lines. These services will simply not be available. Customers will need to evolve their current telecoms before 2025 in order to have voice services following the switch off. 

Now is the time to start talking to customers about migrating their comms to the new technology. Cloud and hybrid infrastructures that can accommodate hosted telephony or VoIP systems need to be prioritised. 

In the lead up to 2025, the traditional exchanges that we’ve all come to recognise as the green boxes on our streets will gradually be decommissioned for traditional services. Stop sell orders will be implemented meaning customers will be unable to order any new analogue or ISDN phone lines. It also means that new phone lines or channels to existing installations will not be possible.

Please note: Once an exchange has been placed under ‘stop sell’ restrictions, if FTTP is available at the address, then this will be the only product you can connect to. Broadband checkers may indicate that other products and services are available but they will not be able to be purchased when a stop sell comes into force on that particular exchange.

Next Generation Network & Broadband

A Next Generation Network (NGN) is a packet-based network, capable of providing

telecommunication services. Mobile connectivity has been operating over packet-based networks since mobile data was first enabled.

An NGN offers users unrestrained access to networks and competing service providers, as well as supporting generalised mobility that will allow for the consistent and ever-present provision of

services to users.

What is SoGEA?

SoGEA is a data-only broadband solution that is provisioned on a single order. Voice can be activated as an OTT (Over The Top) service through system or router configuration. 

You may be familiar with this as a technology as it is based on the current FTTC (Fibre To The Cabinet) technology that uses a combination of copper and fibre technology and also doesn’t need a traditional voice/landline for voice services.

SoGEA is available as 40:10 and 80:20 services, at 100GB and unmetered. There are two installation options – Standard Managed Install and Premium Managed Install.

How will SoGEA benefit your business?

  • Equal speeds to FTTC
  • Cost and installation times are lower than Ethernet-based connectivity technologies
  • Future-proof connectivity to prepare your customers for the move to All-IP
  • Available to 28 million UK premises
  • Migration is made simple
  • Simple to sell and simple to support

What is FTTP?

FTTP (Fibre to the Premise) uses a full-fibre connection and offers speeds reaching 330MBps. 

The FTTP product uses fibre infrastructure and provides an alternative solution to SoGEA.

FTTP and SoGEA seek to complement each other and as a result, SoGEA and FTTP may both be available within an individual exchange area, but each set of premises will generally only be served by one product or the other.

Want to know more?

If you’d like to know more about the move to All-IP, the BT ISDN switch off and what they mean for your business, please take a look at our All-IP guide. Alternatively, you can speak to a member of our team by emailing us at hello@bamboo.tech or by calling 01242 246 700.