Major telecom providers in the UK announced plans to end the use of PSTN

Many of the major telecom providers in the UK have already announced plans to end the use of PSTN and replace it with All-IP services. Indeed, some have already started phasing out support for PSTN.

BT intends to have switched all users to IP by 2025. Orange has set a more ambitious goal of having all digital networks by 2020.

Why are they doing it?

There are a number of key reasons behind the move towards all-IP networks. It will help to reduce costs for providers, with specialists such as GTI Global able to offer highly competitive voice termination and origination services. It will also give consumers greater choice and flexibility when it comes to the selection of voice services and it is also the first step towards the eventual retirement of copper networks. The latter is also connected to the UK Government’s target of deploying Gigabit-capable FTTP-style broadband ISP networks across the country by 2033.

There are four recognized paths to All-IP migration. These are:

1) Voluntary migration – where the end-user migrates to a VoIP-based product from a PSTN one because they are attracted by the superior quality/functionality.

2) Forced migration – where the end-user is given a firm date for the closure of the PSTN/ISDN and therefore must make the switch in order to enjoy a continued telephony service.

3) Passive migration – where the provider is able to migrate customers to an All-IP network for them, with little or no disruption. In these cases, the customer doesn’t need to do anything.

4) Coincidental migration – where the end-user moves from a PSTN based to an inherently IP-based product such as FTTP.


There are a number of significant challenges when it comes to switching from PSTN to IP. Similar migrations are in process in several countries including Germany, Switzerland, France, and New Zealand. It is clear from these programmers that there are lessons that can be learned and applied in the UK.

One of the main lessons highlighted thus far has been the need to try and avoid ‘forced migration’ insofar as is possible. In Germany, some issues with communications led to more forced migrations than anticipated. However, Germany’s migration now stands at over 80%.

Further lessons from other countries including an indication that bundling IP services together with other products was more effective in terms of migration than simply trying to persuade people to switch by highlighting the benefits.

Unlike some of the other countries, in the UK there is a regulatory requirement for an uninterrupted power supply in order to protect vulnerable customers. Providers must also make sure that access to emergency services is not jeopardized, particularly in the event of a power failure.

Another area of concern is the fact that the UK operates a number forwarding system whereas many of the other countries have a centralized database.

Clearly, there is some way to go but the associated extension of the UK’s infrastructure will have far-reaching benefits.