Thirty years on…ISDN is finally on its way out
Posted by Caroline Moore on 23/08 at 12:10 PM Telephone lines,
ISDN on the way out

The telecoms industry is full of marketing material and news updates on the demise of ISDN telephone lines. Outside the comms industry, this is just another meaningless acronym being bandied around at will. It may help to put the ISDN story into a meaningful context.


ISDN is a digital telephone line service that was introduced in the late 1980s and offered access to a range of advanced features (in its day), such as direct dial numbers, calling line identity, external call transfer/divert, etc.


Some 30 years later, it’s hardly surprising that we are beginning to talk about replacing it. It will join the tech scrapheap, along with the Compaq Deskpro 365s, Motorola 8000X mobile handsets, Telex machines and other outdated hardware that was used at that time.


ISDN’s outdated hardware, expensive costs, inflexible software and limited capacity are not designed to meet the needs of today’s business user.


BT will stop selling ISDN lines from next year and will switch them off completely in 2025. As referred to in our previous blog, Apprentice army starts mammoth upgrade as ISDN switch-off looms; this is not a small job. Openreach needs to upgrade 15 million phone lines before 2025, so work is starting next month to complete all the work before the deadline.


While businesses could try to sit tight for another five years, the frustration is that they are missing out on the benefits of newer voice services.


We are offering our customers multiple ways of meeting this deadline:


Switch to SIP voice services
You will need to find out if your telephone system is compatible first. Sometimes you just need a software upgrade or additional licence to be able to use these internet-based connections for calls instead of ISDN lines.


Convert your phone system
Where telephone system is not compatible with SIP, we can offer a convertor that will enable you to keep your existing phone system and prepare you for the switch-off deadline. 


Migrate to a cloud-hosted telephone system
Replace your existing on-premise telephone system with a pay-per-user-per-month service. Whether hosted in a private data centre or in a network of public data centres, these calls are run over SIP.


The benefits of all the above include:

  • Free calls to UK numbers starting 01, 02, 03 or 07
  • The ability to have multiple dial codes on one line i.e. have a London number on an Exeter line without paying for a divert
  • Built-in business continuity with every DDI being able to be diverted to individual mobiles at the click of the mouse
  • Easy growth as extra channels can be quickly added to accommodate business growth

Modern phone systems can also be integrated with collaboration tools, such as instant messaging, audio and video conferencing, contact centres and CRMs. With all the benefits in mind, holding onto an ageing telephone system to sweat the asset may not be the right thing to do in terms of saving money and increasing productivity!


We would not dream of using a Compaq Deskpro 365 as our PC, so why would we think using outdated voice services is a good idea? If this blog has made you think and you would like help switching from ISDN, we are happy to help. Please do not hesitate to contact me at sip@swcomms.co.uk.

Posted by
Caroline Moore's avatar
Caroline Moore on 23/08/2019

Former newspaper journalist, Caroline joined the company in 2008 with no previous knowledge of the industry.

She set about stripping back all the jargon to produce plain English marketing collateral to support the sales teams. Now slightly more well-versed in the dark arts of voice, connectivity and data services, Caroline writes blogs, case studies, data sheets and social media updates to engage with potential and existing customers.

This industry is far cry from her previous working life when she worked as communications manager for Exeter Chiefs and Northampton Saints.

Contact: caroline.moore@swcomms.co.uk

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