Did you know that your current telephone ISDN/PSTN infrastructure is due to be phased out? And that it's going to fundamentally change how your business communicates in the future?

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Jon Smith General News

The End of Telephones as We Know Them - EC Computers Update on ISDN/PSTN closure

Did you know that your current telephone infrastructure is due to be phased out? And that it's going to fundamentally change how your business communicates in the future?

End of the line for ISDN and PSTN

Got your attention yet? Is this the end of the line...

You might want to be sitting down for this news: telephone systems in their current format are about to undergo a huge change in the next couple of years. The basic outline is that Openreach (the company responsible to all infrastructure related to telecommunication (the guys in the van that you see busy with the green boxes on the side of the road when things go wrong), have made a big announcement. From the early 2020s Wholesale Line Rental (WLR) will no longer be offered by their company, so all WLR products that businesses and individuals use will not be available anymore.

This announcement has some quite serious implications as it affects over 28 million telephone users which give you some idea of the scale of this decision. So, what is going to happen? Simply put, times have changed, and in an effort to stay up-to-date with technological advances  and consumer preferences, Openreach is moving with the times. They are shutting down their copper wire Public Switched Telephone Network (PSTN - the phone lines) and moving their operations to Internet telephony based on fibre products that are faster.


What will that mean for us as telephone users? There are a number of services that we use on a daily basis that will no longer be available. This includes:

  • ISDN services that businesses use to make calls will no longer be offered.
  • Analogue phones that run on the copper wire network between the exchange and your phone will be deprecated.
  • Also, many broadband products will also go.

Well, what are our options? There is a transition period that is due to begin in 2021 and is estimated to last for four years. In this time, a transition system will be in use to help bridge the changeover from the old system to the new. The transition system SOTAP (not to be confused with the popular acronym for the Sexual Offenders’ Treatment Assessment Program), refers to the Single Order Transitional Access Product. SOTAP is a smart bit of tech that enables individuals and businesses currently using traditional copper lines to move to a pure broadband service. This service does not rely on either analogue lines (neither PSTN not ISDN) and will allow for the supply of a digital voice service using a system that is fast and reliable.

Dont' worry, we’ll walk you through some of the changes that are coming, listen to your requirements, and make suggestions on a clear plan of action. Call us on 0117 200 1000


Is that all? Not quite… Internet telephony still requires an internet connection. Many homes and businesses use either ADSL (Asymmetric Digital Subscriber Lines) or FTTC (Fibre to the Cabinet) which are still copper-dependent and will therefore no longer be available in the near future. This means that at some stage, within the next six years, both phones and internet connections will need to be updated. Fibre options available include either a Leased Line (FTTP – Fibre to the Premised) or SOGEA (Single Order Generic Ethernet Access).

Businesses that still use ISDN can switch comfortably and quickly to SIP trunking or hosted VoIP with or without BT. Their numbers can be ported and retained and the whole service can be set up within weeks.

Although the BT ISDN end of life is set to 2025, BT have not yet set anything in stone. Whilst you will be unable to buy systems that use ISDN and PSTN after 2020, it doesn’t mean if you haven’t made the switch, you’ll automatically be switched off. BT will NOT turn them off before they have an alternative firmly in place.

The final date is dependent on how successful UK wide fibre roll- outs are, as without the connectivity to run there is no real alternative to ISDN.

Connectivity in the UK is getting faster and faster, so who knows it may happen even sooner than 2025. But while the date may move by a few years here or there, the one certainty is this; ISDN and PSTN are outdated technologies that are simply not as good as modern VoIP.

Whichever options you choose, cloud-based telephony is the future of communication and it will be here sooner than you think so get planning now and make sure your business doesn’t get left behind.

Answered all your questions? Probably not. That’s why EC Computers is here to help. If you want to know what is going to change and how it will affect your business, our team is waiting for your call. We’ll walk you through some of the changes that are coming, listen to your requirements, and make suggestions on a clear plan of action. Call us on 0117 200 1000

See EC Computers options for your Hosted Voice and On-Premise Telecoms with SIP trunks here

Are you in Bristol - Gigabit City Fibre may be an option for you

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Key Telecom Acronym Definitions


PSTN - Public Switched Telephone Network

The PSTN allows calls to be made all over the world using analogue voice data. It consists of copper telephone lines, fibre optic cables, microwave transmission links, satellites, undersea telephone cables and mobile networks.

The PSTN has evolved from a network of fixed-line analogue telephone systems to an almost entirely digital network.

Whilst the PSTN requires physical lines, IP telephony is all digital and requires nothing more than the internet to be fully operational.

WLR - Wholesale Line Rental

WLR3 enables CPs to offer their own-brand telephony service over the PSTN copper network.

Openreach provides, maintains and repairs the lines so that CPs can supply services to their customers, without having to maintain a network themselves.

ISDN - Integrated Services Digital Network

An ISDN service is a telephone-based network system that transmits voice and data over copper wires. ISDN enables customers to make phone calls while transmitting files and videoconferencing, but has now been superseded by much more reliable and faster broadband and Ethernet services. There are two types of ISDN: ISDN2 and ISDN30.

ISDN2 comes in two variants; ISDN Standard and ISDN System and can deliver two simultaneous 64kbps connections over a single line.ISDN30 offers speeds of 64kbps over up to 30 channels per bearer.

LLU SMPF - Local Loop Unbundling Shared Metallic Path Facility

Shared Metallic Path Facility (SMPF) enables CPs to offer broadband services over a WLR line while another CP (or the same CP) supplies voice services on the same line – hence it being “shared”.

SLU SMPF - Sub-Loop Unbundling Shared Metallic Path Facility

Sub-Loop Unbundling (SLU) provides access to an access point in the local network (usually the Openreach street cabinet) to enable SLU CPs to connect to their Fibre network, providing voice services over copper and broadband over fibre.

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