VoIP uses an internet connection to relay calls, whereas ISDN relies on physical cables. Businesses have relied on an ISDN line in the past to stay connected, hence the need for a telephone system. However, the stability of IP technology in more recent years, such as VoIP and SIP, has piqued the interest of business owners looking to switch and cut back on costs. The confidence in IP technology has increased so rapidly that ISDN lines are currently being phased out and will be switched off by 2025.
With the improvements in fibre infrastructure and the depreciation of the copper network, IP technology now seems to be the best option for businesses. In this article, we discuss how VoIP will replace traditional telephony and how your business can prepare for the switch…

WHAT IS VOIP?
VoIP stands for Voice over Internet Protocol. In comparison to ISDN, VoIP is a relatively new piece of technology. Instead of using a physical telephony circuit, VoIP uses the internet to relay calls. This will create significant savings over the cost of a traditional phone system.
WHAT IS ISDN?
ISDN stands for Integrated Service Digital Network. ISDN simultaneously transmits voice and data over digital and copper lines that are connected to telephone exchanges across the world. Before ISDN, telephone lines could only provide a fast connection over a single line. ISDN made it possible to connect many users to already-existing digital telephone systems, this meant that voice and data could be used at the same time.
WHEN IS THE ISDN SWITCH-OFF?
Back in 2015-16, it was announced that the ISDN ‘phase out’ would begin in 2020, with a target switch-off date of 2025. You will no longer be able to order new ISDN lines after 2020, which has now been revised to September 2023, because they will no longer be available for purchase. By December 2025, the copper-wiring technology that currently powers our landlines will be switched off and turned into a fully digital network.
HOW WILL VOIP REPLACE TRADITIONAL TELEPHONY?
ISDN links to your phone systems using physical phone lines, allowing calls to be routed through to your business. You pay a monthly fee plus any call expenses for those phone lines as they are leased. VoIP eliminates the requirement for leased lines because calls are routed through your internet connection. The majority of your call charges are avoided as a result of this.
Users can make calls over the internet using VoIP, which converts analogue signals into digital signals that are transferred as data packets. A regular analogue phone line is no longer required. Low-cost calls, immense flexibility, and the ability to add new lines at any moment are all advantages of VoIP.
WHAT ARE THE ADVANCEMENTS IN TECHNOLOGY FOR THE END-USER?
In 2020, the number of people working from home doubled, reaching 25.9%. Businesses realised that their employees had begun making the shift away from the conventional office work and that the traditional telephone wasn’t ideal anymore.
Many businesses have started to make the switch over to a VoIP system, but what does the end-user gain using VoIP over a traditional phone?…
Better functionality – VoIP solutions tend to offer greater function over landlines as they allow users to host video calls and transmit multimedia messages. Systems often include additional features such as voicemail, call analytics, anonymous call rejection and voicemail-to-text transcription.
Easily scalable – With traditional phone systems, it was easy to reach the limit of connected phones or numbers available to be used. Because VoIP is cloud-based, it can be scaled up as your company expands.
Being mobile (Portability) – VoIP isn’t tethered to a physical location as with traditional methods, so it allows staff to answer calls from anywhere with an internet connection. VoIP allows for a more mobile workforce, utilising ‘soft phone’ applications you can answer your work number through an installed app on your mobile device so that you never miss an important call when working remotely.
Simplified conferencing – With traditional systems, you were able to host multiple callers however it was normally at an additional cost. With a VoIP service, these features are usually native so the costs are built-in.
An additional benefit of VoIP is that it can be integrated into other applications. With Microsoft Teams, for example, you can integrate VoIP to allow callers to make use of the other features as well, such as video conferencing.
HOW CAN I PREPARE FOR THE SWITCH OVER?
With modern technology advancements, telephone services will no longer have to rely on the ageing copper infrastructure. The ISDN switch-off will impact all businesses that don’t yet use VoIP. If you currently have an ISDN line, you will need to replace and upgrade your telephony by December 2025 to an internet-based connection to place a phone call.
VoIP technology is much more cost-effective and flexible than a traditional telephone, so if your business is looking to switch over systems, then we can help you. Contact us to switch over to a VoIP system today.