top of page

The BT PSTN switch off - what does it all mean?

BT will be switching off the PSTN phone network and its ISDN services in 2025 to move to an IP based network. In theory, that gives you a good few years to get you telephony sorted.

In fact, you should be thinking about doing it now.

PSTN - the public switched telephone network - is a circuit-switched, analogue network that was designed to work over copper wire. ISDN was developed to let you use voice and data over the same line, but it still used the old network with all its inadequacies.

BT will be moving to an IP (internet protocol) based network that's digital by nature, and designed to work over fibre. But you can already move to voice over internet protocol (VOIP) with all its advantages; why wait?

VOIP turns the PSTN network idea on its head. PSTN was designed for analogue voice and adapted to carry data over it; VOIP uses a digital network designed for data to carry voice calls.

You could keep your business telephony pretty much the way it is and just use SIP to carry a phone line over your internet connection using your existing PBX through a SIP gateway. But by changing to hosted VOIP, you get extra benefits. Hosted VOIP moves your entire system online, and moves your PBX offsite or into the cloud.

What does it mean for your business?

First of all it gives you much more flexibility. You can arrange your telephony to match your internal business environment. If your corporate treasurer moves office, or even moves city, her phone line can go with her. Your sales team have the same phone numbers whether they're working from home, from a client site, from headquarters or from a local office - and they're all patched into the same network, so arranging a conference call with three people in different offices is child's play.

Because phone numbers aren't attached to a particular desk or device, hosted VOIP is great for telecommuters. Floods, blizzards, or train strikes are no problem if your staff can simply switch on at home - and your customers won't even notice

Connecting a new user is just plug-and-play. That's good news for fast growing businesses but also for anyone who uses temporary staff for peak periods, or who might want to integrate a consulting team into the business. You could even bring clients into the network, if you wanted - great news for outsourcing businesses and virtual assistants.

Hosted VOIP can deliver major cost benefits, too, though you'll need to do a bit of work to see what's the best tariff package for your business; some hosts charge per seat, while others charge based on usage.

From a business continuity perspective, hosted VOIP delivers real resiliency. A good host will give you automatic failover, multiple access routes, and high availability, and your network is location-independent, too.

Hosted VOIP will deliver all the services you're used to from a PBX, but can also deliver sophisticated call queueing, call recording, voicemails via email, and analytics. Because it's a digital system, you can integrate voice calls with other applications, such as your CRM system or email. Converged voice and data networks represent a major cost saving.

Unified communications let you use whatever hardware you want on the system - mobiles, tablets, desktop PCs, or IP phones. You don't have to buy a PBX any more; you don't even have to buy a traditional phone for each desk, and if you do, you can use power over Ethernet to get rid of all that spaghetti. One phone, one cable!

It's fair to point out that there are a few issues you need to think about before you make the change. If you have really old phones, they might not work with IP. And if your premises haven't been rewired for years, your old cabling might not cut the mustard.

You'll also need high bandwidth internet access. If you're surviving on a half-adequate phone line in the depths of the English countryside, you'll need to put hard thought into how to upgrade.

So why should you upgrade to hosted VOIP now, and not wait for BT to get around to switching for you?

First of all, hosted VOIP gives you so much flexibility that you really need to put some thought into how to make the most of it. BT will probably auto-upgrade business customers at some point, but that will be based on your existing configuration and that might not be the best deal for your business.

Secondly, BT won't be investing any more in ISDN and PSTN, so network reliability could falter. VOIP is where all the telecoms innovation is happening right now. If you have an ISDN contract coming up for renewal, don't auto-renew - it's a great opportunity to move to a more flexible, cost-effective network that can deliver business benefits from day one.

And thirdly, tell your finance people that hosted VOIP will be considerably cheaper than ISDN. The sooner you move, the quicker you can make those savings. A great reason why you should be switching off ISDN before BT gets round to it.

- Andrea Kirkby

bottom of page