2025 PSTN
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PSTN (Public Switched Telephone Network) is the same phone line most people have at home, using circuit-switched copper phone lines. While it may have evolved over the years, PSTN is a very old technology, operating on the same fundamental principles as the very first public phone networks of the late 19th Century.

ISDN (Integrated Services Digital Network), by contrast, came into use in the late 1980s. ISDN allows both voice and data services to be delivered over digital lines simultaneously. ISDN was well-suited to businesses, as it could support early video-conferencing systems at the same time as an analogue phone line. For a time, it could also offer the fastest internet
access available (128 kbps). Naturally, since ISDN is no longer the place to go for video-conferencing or a fast internet connection, its USP has quickly been eroded.

BT is moving its entire voice network to voice over IP (VoIP). VoIP has been a proven platform for voice for some time now. It works. If your business has renewed its telephony sometime in the last few years, you may have been told about it (but don’t be surprised if you haven’t, since IP is a whole new game that has been growing steadily in the background, with more and more businesses realising the benefits demonstrated by the early adopters).

VoIP has many advantages over PSTN and ISDN too;

• it is much quicker to provision new lines,
• you can reduce your line rental due to needing fewer physical lines,
• and it is vastly scalable and flexible – for example you can redirect calls to different parts of the country via a web browser, or have a single phone number follow you around the world irrespective of where you’re working.

By converging all services – voice, data, video, and even broadcasting – to the IP protocol, BT only has to maintain one network, not several. It is also worth bearing in mind that 2025 might not be Doomsday for ISDN. The date is not set in stone.

It is BT’s intention to stop selling PSTN and ISDN by 2020 and shut it down completely by 2025 – but this is assuming it has managed to switch all customers over to IP services before then. This means that a viable alternative must be available to everyone well before 2025. For many businesses today, ISDN is still the best they can get. BT will not turn them off before they have an alternative firmly in place.

You will no longer be able to buy any additional PSTN or ISDN lines from 2020. While 2025 may seem a long way off, it is only just over three years away. If your current traditional telephony contract is up for renewal within the next few months, now is the time to start exploring the benefits of VoIP and SIP technologies.

Assuming you are in an area that can support VoIP technology, there are two things you need to consider:

1. Is your internet connection good enough to deliver VoIP?

You will no longer be able to buy any additional PSTN or ISDN lines from 2020. While 2025 may seem a long way off, it is only just over three years away. If your current traditional telephony contract is up for renewal within the next few months, now is the time to start exploring the benefits of VoIP and SIP technologies.

Assuming you are in an area that can support VoIP technology, there are two things you need to consider:

2. Does your office phone system support VoIP?

Most new office phone systems already support VoIP, but if yours doesn’t, you can either replace your entire phone system with an IP one (worthwhile if your handsets are looking tired), or just invest in an IP-enabled on-premise PBX (the box that connects your internal phone system to the external phone network). A hosted telephony solution is often the
preferred way to deliver VoIP services into an organisation.

Given the advantages of VoIP over ISDN, and the issues with ordering legacy services, we recommend not.

Whether or not the 2025 date will stick remains to be seen. The final date is dependent on how successful UK wide fibre rollouts are, as without the connectivity to run there is no real alternative to ISDN. Connectivity in the UK is getting faster and more stable, 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. So don’t stay in the past.