VoIP phone systems vs ISDN lines

VoIP phone systems are becoming a hit with businesses as they set to improve businesses productivity with staff

This is a common question asked when it comes to telephone systems because people wonder what the difference between the two are and how one is more beneficial than the other. In business you want the most cost effective solutions but a great service. This blog is a perfect example of what products you should invest you time in rather than going for an easier option. 

What is an ISDN line?

An ISDN internet service is a telephone based network system that is operated by switches or a dedicated line. The way you call people is done by transmitting data through physical telephone wires which is a fast calling solution. It does have its limitations as it does require specialized digital services and it can be costly for national and international calls.


VoIP stands for Voice over Internet Protocol which is a phone system operated by the Internet. Easily make phone calls both nationally and internationally whilst saving costs for your business. Calls are routed through your broadband connection rather than an ISDN rental line which makes it more efficient if you have a stable Internet connection. 



  • Higher data speeds than an analogue phone
  • Calls do not rely on the Internet
  • ISDN only takes a couple of seconds to launch
  • Calls can be transferred from your office to another number


  • Costs less to run and make calls than on an ISDN line
  • Flexible for staff to call on different devices 
  • Numerous calls can come in at the same time with minimal problems 
  • VoIP faults can be fixed quicker than ISDN faults



  • High cost for rental lines and equipment
  • Takes longer to repair any faults
  • More expensive to make calls than VoIP
  • Takes longer to set up than VoIP phone systems


  • Reliable Internet connection
  • Lose power to phones if Internet goes down (on premise not hosted)

The Internet is increasingly improving and becoming stronger which makes VoIP a more reliable and stable solution for businesses. With enhanced flexibility for staff and an easy-to-use interface it has huge benefits overall. 

If VoIP is something your business is looking to move over to, our qualified team will be able to help advise on the best solution for you and quickly implement the system with minimal disruption to day-to-day business. 


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