The Demise of ISDN & the Impact on Professional Services

Find out why professional services organisations are now looking at VoIP as an ISDN upgrade and what the benefits are…

The ISDN standard was set in the late 1980s. 

During this era:

  • The world wide web was just being invented
  • Mobile telephony was just finding its feet – and still analogue
  • Urgent business documents were often sent by fax

Since the launch of ISDN, many changes have taken place in the business world:

  • Remote working, flexible working and hot-desking have exploded
  • Many employees use both mobile and fixed line telephony services during the workday
  • There has been increased focus on service, efficiency, business continuity and disaster recovery
  • IP-based services are commonly used by many organisations

Businesses are now considering an ISDN upgrade to newer technology that is a better fit for purpose. Here’s a comparison between ISDN and VoIP:


  • Lacks the agility needed to meet the needs of today’s fast-moving consumers
  • Management of multiple offices can be time consuming, maintaining consistency of service across office id often difficult
  • Scalability is slow and expensive
  • Often requires substantial CAPEX investment
  • Disaster recovery is slow
  • Can’t be combined with modern technologies like Ethernet to enhance voice services 
  • BT has announced end of life for ISDN by 2025


  • Improves service features for greater gains
  • Increased flexibility to meet the changing needs of your workforce
  • Improved scalability to help drive business growth 
  • Enhanced quality of services for customers
  • Improved resilience with built-in disaster recovery provisions
  • Reduced cost with significant savings to be made on call costs and line rental 
  • Increased visibility of performance metrics to improve productivity and overall business performance

ISDN End Of Life Timeline

What are the next steps?

  • Carry out an audit of your telecoms system – when was the last time you looked to upgrade?
  • Find out how much your ISDN lines and on-site PBX system is costing you – how much could you save?
  • How resilient is your existing telecoms provision – how would prolonged downtime affect your business?

Thinking of an ISDN Upgrade?

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