ISDN Migrations

We help you navigate the entire ISDN migration process, from choosing your new solution to managing your switch over in a way that gives you no down time.

Why switch with us?

Switching from ISDN with BT is not your only option. In fact, it’s rarely your cheapest or best option. 

We care about your business and are committed to finding cost-effective solutions that balance change over costs and sustainablity.

Unbiased Advice

We’re technical advisors not salesmen, so we provide expert advice on choosing the best ISDN alternative for your business.

No Lock-ins

Technology improves and businesses grow. We don’t lock you in to inflexible long term contracts that trap you in outdated technology. 

Proven Process

Our proven ISDN migration process minimises disruption and maintains continuity. 

What you need to know about ISDN

What is ISDN?

ISDN refers to the digital voice and data lines that were rolled out by BT in the 90’s and early 2000s. It was a reliable, but expensive way of providing businesses with voice connections.

BT is stopping new ISDN orders by 2020 and will be discontinuing ISDN services by 2025 in favour of VoIP.

How will the ISDN phase out affect your business?

To continue to make calls in the future, UK businesses will either need to migrate away from ISDN to a cloud based IP telephone system or connect their existing telephone system to a SIP trunk.

While 2025 is a while away, UK businesses are already switching now so they can take advantage of the reduced costs and advanced features of cloud based telecoms systems that connect over much faster fibre internet connections.

When will ISDN be swtiched off?

BT is discontinuing its ISDN services by 2025 and ceasing new orders by 2020.

Do we need to switch right now?

No. You do not need to migrate from ISDN to VoIP right now, however, many businesses choose to.

Hybrid approaches that utilise gateways can allow your business to stay on ISDN for a few more years without compromising quality.

What is an ISDN v.s. VoIP?

While ISDN was a great, there are better technologies now exist that provide more functionality and flexibility.VoIP is a way of providing voice over the internet. It has 4 primary benefits, and numerous hidden benefits.

  1. With VoIP greater control over your costs and the channels that you need for growing businesses.
  2. Employees can make internal calls for free and you can use call routing to make all calls easier and cheaper.
  3. Employees can access their office number from anywhere, or your whole office can bring their numbers if they move.
What is an ISDN to SIP gateway?
As an alternative to a full migration to hosted VoIP, businesses can install gateways that tricks the phone systems to thinking it’s still connected to ISDN.
What happens to my phone numbers and call routing?

If set up properly, you can keep your phone numbers and call routing.

But many businesses use ISDN migration as an opportuntiy to optimise their call routing to increase business efficiency and accelerate their ROI.

We provide number porting as part of our migration process so that you can keep all your numbers, even if moving locations. 

Will call quality be ok?

Yes. In fact, with higher quality codecs used by VoIP call quality will improve.

If you’re migration provider optimises your broader infrastructure you usually get improved data transfer and video performance too.

Is the system stable?

Because you don’t need to rely on aging hardware that tends to break, non-ISDN telecoms systems are usually more reliable.

With VMware and other hypervisors you can build in failover, redundancies and business continuity plans.

We recommend businesses have a careful change management plan during migration, and design their new solution to manage risk.

Will my teams be able to use the new system?

Modern phone systems have been designed to be easy to use and integrate into other systems like your CRM.

Experience shows that most teams find VoIP solutions to be more intuitive and easy to use. However, teams that invest in training get more out of their new systems and adopt features faster

We’ve developed training plans to ensure teams can take full advantage of new systems.

What are SIP trunks?

Session Initiation Protocol (SIP) trunks are virtual phone lines that allow you to make voice calls over the internet. 

They can either replace or work alongside traditional analogue or digital ISDN phone lines.

Altnernatives to ISDN

Full migration to VoIP

Given that ISDN will be completely phased out anyway most UK businesses opt to modernise their telecoms system by moving calls from ISDN to digital solutions. 

Alternatives to ISDN include: 

  1. SIP trunks 
  2. Hosted VoIP
  3. Unified Communications

Hybrid Approach

For cost conscious, or low call volume businesses, we deliver innovative solutions that allow them to stay on ISDN for a few more years without compromising quality. 

Using gateways, we spoof the system to thinking its still connected to ISDN so a full replacement isn’t required. 

Get unbiased ISDN advice. Book a no-lock in site assessment.

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The hidden benefits of life after ISDN 

Most of our clients approach us looking to move away from their costly BT lines in preparation for the ISDN phase out. In the process they tend to find huge hidden benefits that were previously unachievable.

Your teams can operate beyond the desk phone

Upgrading to a digital solution means your teams can access your telecoms system without having to use a desk phone.

Reduced hardware costs

Hardware costs decrease because you can BYO hardware or use software apps to make calls.

Lower call rates

You can save money on call costs and line rental. As a cloud based service, the physical overheads are removed.

Scale and grow

SIP channels can be increased straight away, with no lengthy installation periods.


No need to dial complex number combinations to call or answer the phone. Just click the digital switchboard and answer a call. 

Quality video calls

Infrastrucutre that can support high quality video calls. 

Business continuity

Staff can use their office phone anywhere in case they can’t get into the office. 

Absorb seasonal changes

You can scale easily to absorb seasonal or short-term changes. 

Our ISDN Migration Process

1. Discovery

Free Site Assessment

We provide you with a free assessment of your site to determine the suitability of moving away from traditional ISDN. 

We identify your ISDN phone lines/channels and the DDI telephone numbers associated with your current ISDN service.

Our Recommendation

We recommend the best alternative solution to ISDN for your business. 

Optimise or Mirror 

Work with you to determine what parts of your system should be mirrored and what should be optimised and streamlined. 

Make Network and Internet Ready

Where necessary we reconfigure or provide new network and internet connections ready for your new system.

2. Plan and Optimise

3. Ensure Seamless Handover

Submit ISDN Number Port

We submit a number porting request to move your BT ISDN telephone numbers (DDIs) so you’re ready from day one. 

Change Management 

We provide your management team with information on how to manage and prepare for change.

Install Handsets & Softphones

We install your new handsets or softphones and connect them to your system.

Staff Training

We provide on-site or video based training resources to your staff on how to use the new system. 

Bedding In

We provide support to help you and your people adopt the new system and get the most out of the new features. 

4. Embed

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