The Copper Telephony Switch Off, and What It Means for Your Business

In 2015, BT Openreach announced its intention to fully decommission the UK’s copper-based telecommunications infrastructure by the end of December 2025.  


Often referred to as the PSTN (public switched telephone network), this infrastructure is becoming increasingly expensive to maintain, and often struggles with the demands placed on it in our digital age.  In the coming years, BT will gradually phase-out the old infrastructure in favour of full fibre broadband, which promises to be up to 10 times faster and far more reliable. 


Along with the retirement of the copper-based infrastructure, the shutdown will see the discontinuation of the telephony products which rely on it, such as ISDN lines, which are still used by around 70% of UK businesses.  Integrated services digital network (ISDN) defines a set of communication standards which make the simultaneous digital transmission of voice, video and data across the copper circuits of the PSTN possible.   


Why is ISDN being decommissioned? 

When it was first introduced in 1986, ISDN was a revelation.  With improved call quality, vastly improved data transfer speeds compared to the dial-up products it replaced, and the ability for a single line to carry multiple signals simultaneously, ISDN moved the game on immeasurably.  Fast-forward to 2022 however, and ISDN is sufficient at best.  So why does ISDN no longer cut it?… 


  • ISDN lines are inflexible.  Fixed ISDN phone lines assign phone numbers to fixed physical locations.  Today’s businesses demand enterprise mobility, something an ISDN phone system doesn’t afford. 
  • ISDN lines aren’t easily scaled up.  Adding new lines involves a physical installation, a process that can take up to 20 days and involve considerable disruption. 
  • ISDN is slow compared to modern alternatives.  Full fibre offers speeds up to 10 times greater than ISDN products thanks to the vastly superior bandwidths afforded by fibre optic cables compared to copper wires. 


What is the old system being replaced with? 

BT is gradually replacing the old network with its Ultrafast Full Fibre broadband.  This new system will see homes and businesses connected directly to BT’s exchange infrastructure by fibre optic cables, bypassing the on-street cabinets.  BT predicts 70-80% fewer faults with this new arrangement, and speeds of up to 1Gbps – over 10 times faster than many current services. 


With the new infrastructure being rolled out region-by-region, town-by-town, you could see the introduction of full fibre in your area well before before the December 2026 deadline.  BT have made it clear that they will cease the sale of traditional telephony products (such as ISDN) in areas where full fibre connectivity has reached 75%, so switching to a futureproof alternative sooner rather than later could prove a smart move. 


How should I prepare my business for the PSTN switch off? 

If you currently rely on a PSTN or ISDN product for your business’s telephony needs, you will have to transition to a IP-based system before the big switch off to ensure your business doesn’t suffer a telephony black out.  An IP-based system uses something called ‘voice over internet protocol (VoIP): a set of communication technologies and standards which allow voice and multimedia sessions to be conducted over the internet.   


For businesses looking for futureproof telephony, 2 of the most compelling are Hosted PBX services and SIP trunking.   


A quick guide to SIP trunking 

SIP stands for ‘session initiated protocol,’ and is a type of VoIP technology that allows users to make use of existing PBX (private branch exchange) phone system hardware.  SIP trunks function like virtual phone lines, and as long as your private branch exchange server is IP-ready or made IP-ready by the addition of a VoIP gateway, then SIP offers a cheap and convenient way to continue using the phone system you’re used to. 


Advantages of SIP trunks 


  • Get value from your existing phone system.  SIP trunks allow you to extend the life of an existing on-premise phone system. 
  • Highly customisable.  Because you own and control the system’s hardware, you can add functionality at will.   
  • Boosted productivity.  SIP trunks allow voice, video and data to be united into a single interface, a practice known as ‘unified communications.’ This creates a more slick user experience and improved productivity. 


Disadvantages of SIP trunks 


  • Maintenance is your responsibility.  Because you continue to house the underlying hardware, your IT team remain responsible for its maintenance and security.  You’ll also have to budget for replacement hardware when your PBX server nears the end of its life. 
  • You could miss out on innovative features.  Hosted PBX systems often come packed with a host of innovative call handling features as standard.  You could miss out on these if you choose to continue using your on-premise PBX. 


A quick guide to Hosted PBX systems 

A hosted PBX system takes the infrastructural element of a traditional phone system and hosts it in the cloud.  As with SIP trunking, Hosted PBX systems enable full enterprise mobility, with the ability to access the phone system from anywhere via a reliable internet connection. 


Advantages of hosted PBX systems 


  • No maintenance overheads.  Hosted PBX systems can be accessed via your existing internet-capable devices and with no server infrastructure to operate and secure maintenance overheads are virtually non-existent. 
  • A great way to introduce new telephony features.  Hosted PBX systems often feature a range of call handling features as standard, such as auto attendants, call recording, call queueing, call routing and screening, voicemail-to-email and much more.   
  • Unified communications.  Many hosted PBX systems incorporate multiple communication channels into a single interface for a streamlined communication experience.  Some also enable CRM integration bringing data and communication together for enhanced productivity. 
  • Affordability.  Hosted PBX systems are almost always offered on a per-user subscription type basis, with generous call allowances included as standard.  Cloud-hosted VoIP offers excellent value calling compared to traditional telephony products, particularly when calling foreign numbers. 


Disadvantages of hosted PBX systems 


  • Less cost-effective for larger workforces.  For workplaces with over 20 phone users, running an IP-capable on-premise PBX can be more cost-effective in the long run. 
  • Less control.  With a hosted PBX system your phone system is limited to the functionality and features provided by the ITSP (Internet telephony service provider).  You also have less say in the security controls and standards protecting the system. 


With the switch to IP-based telephony already well underway, it’s important to prepare your business for the changes ahead to ensure you remain connected.  Get in touch with your IT provider, as they should be able to help you navigate the VoIP options and find a solution that’s a perfect fit for your organisation. 


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