Transitioning From ISDN To Cloud Telephony: A Step By Step Guide 

In our last piece, we discussed the rise and fall of ISDN as a telephony solution for businesses and contrasted its growing disadvantages with the benefits of modern solutions such as VoIP, with the example of the Microsoft Teams Phone System. With ISDN and PSTN networks being completely taken offline by 2025, it’s essential for businesses to prepare to transition. In this piece, we will give a general step by step guide for migrating from ISDN-based telephony to a cloud-based telephony solution.  

Undertaking the Transition: A Step-by-Step Guide 

The simplicity of leveraging many cloud solutions has made arranging the transition to a new solution generally easier than it used to be, however, it’s still important to map your telephony territory and to ensure that a smooth transition can be undertaken for your business.  

Telephony Assessment  

Firstly, although ISDN is an outdated solution, no two businesses are the same. There may be some (albeit rarer) cases where keeping ISDN telephony continues to be more cost-effective for now.  

Begin by assessing your current communication needs and the opportunities around in the market. What are the relative strengths and weaknesses of your existing ISDN setup? By assessing the pros and cons around features, pricing, and potential transition costs (more on that shortly), you can move with confidence to planning a transition.  

Choose Your Alternative Solution 

VoIP and SIP (Session Initiation Protocol) offer beneficial alternatives to the vast majority of businesses today. In a nutshell, for a business VoIP can be a virtually wireless solution (excepting internet broadband lines), while SIP offers a still modern alternative that’s often useful to larger organisations that wish to rely on copper line lines.  

Whichever solution you choose within these two umbrellas, it’s important to get clear on how they will be implemented for your particular business, based on its IT environment, infrastructure and commercial needs.  

Select a Reputable Service Provider 

A technology expert that understands the ins and outs of telephony and connectivity can take much of the legwork and stress out of the process for your business. When selecting a provider to help with the transition, consider their expertise, the specific solution’s reliability, customer support, scalability and pricing.  


In partnership with a provider, the planning for the migration can be arranged in a way that minimises disruption and risk for your business. Considering how the migration will effect the way that services such as customer support will be provided, are among the considerations to factor in to ensure a smooth transition.  

Upgrade Your Infrastructure 

For modern telephony solutions, a reliable and fast internet connection will do the most justice to your new setup and maximise the benefits that it has to offer. Good connectivity will be essential for reliable and quality calling. You can consult with a Managed Service Provider to ensure that your network infrastructure is prepared to support the chosen solution 

Data Migration and Integration 

Transfer your existing contact lists, call logs, and any other pertinent data to the new platform. At this stage, you can also begin to tap into the new benefits that your solution can offer, by integrating the data with your other applications, notably your CRM (Customer Relationship Management) software.  

Training and Familiarisation 

Provide comprehensive training to your employees to acquaint them with the new system. Highlight the benefits, features, and any alterations in operational processes and offer support to make the transition as smooth and supportive as possible.  

Testing and Pilot Phase 

Prior to the full go-live of your new telephony system, it’s best practice to carry out testing and pilot runs to ensure that it works as desired. As you test the solution, document any issues or concerns that arise so that you can address them ahead of the roll out.  

Phased Go-live 

Depending on the size and context of your business, a phased implementation can be helpful for ensuring that the process is a smooth one that works at scale. Begin by using a smaller group of users, such as a particular department that is well placed to use and benefit from your new telephony solution, and just like the testing phase, carefully document any lessons learned that can then be applied across the business.  

Conclusion: Embrace the Future of Communication 

Migrating from ISDN telephony to a VoIP or SIP based solution can seem like a daunting process, but with planning, assessment, and a phased-implementation with the support of a telephony solutions provider, the process can be much more smooth and seamless. There are many benefits to using a VoIP or SIP based solution compared to traditional ISDN telephony that stand to augment communications and productivity for every business.  

Taking advantage of the latest solutions on the market in today’s world will prove essential for maintaining a competitive edge and achieving profitable growth. We hope this series has been useful to you in your ongoing digital journey. The journey ahead will involve empowering innovation, efficiency, and connectivity; by making a smooth transition sooner rather than later, you’ll be taking another empowering step towards a prosperous future for your business.  

We Are 4TC Managed IT Services 

4TC can support you with all the services you need to run your business effectively, from email and domain hosting to fully managing your whole IT infrastructure. Setting up a great IT infrastructure is just the first step. Keeping it up to date, safe and performing at its peak requires consistent attention. 

We can act as either your IT department or to supplement an existing IT department. We pride ourselves in developing long term relationships that add value to your business with high quality managed support, expert strategic advice, and professional project management. Get assistance with your IT challenges today by getting in touch, we’ll be glad to assist you!