Earlier this year BT announced their intention to switch off the PSTN and ISDN networks by 2025. Customers will be migrated to a single IP core network that ultimately will replace all legacy networks and platforms.
PSTN and ISDN: What’s the difference?
PSTN stands for Public Switched Telephone Network, also referred to as the Plain Old Telephone Service (POTS). Analogue voice data flows over circuit-switched phone lines (copper wires) owned and operated by your phone provider.
ISDN (Integrated Services Digital Network) allows both voice and data services over digital lines, for example video conferencing, data transfer and direct-dial in. ISDN digital services provide multiple channels per line, enabling simultaneous phone calls.
The alternative - VoIP
Instead of using PSTN & ISDN lines (the expensive ‘line rental’ part of your telecom bill) ‘Voice over IP’ transmits voice traffic over your Internet connection. Already many businesses are using VoIP or voice services, not least because it’s a cost effective way to manage telephony within an organisation: this has contributed to the steady decline in take up for PSTN / ISDN services.
For many BT business customers this move by the company will force them to explore new telephony systems, with the added benefit of a more cost effective solution.
So, if your business currently relies on one of the 3.2 million ISDN channels in the UK*, what do you need to know about the ‘big’ switch off?
What to do now
If your current traditional telephony contract is up for renewal in the next few years, now is the time to start exploring the benefits and opportunities of VoIP technology. These include:
Cost savings – no line rental, cheaper calls including International calls, and free calls between your organisation’s offices
Mobility – remote workers can login to your VoIP from anywhere using an Internet connection, even on their mobiles
Multi-functional – as well as voice calls, VoIP can also be used for video-conferencing using a VoIP phone
Integration – because VoIP technology uses the Internet it is possible to integrate it with your other business systems, such as email clients or customer records
Scalability – VoIP technology scales easily to your business. New phone lines can simply be added, reassigned or removed depending on your business’ needs
You’ll also need to ensure that your office Internet can handle VoIP. You will need a baseline of 5Mbps down and 2Mbps up as the bare minimum for a small office of about five to seven users on VoIP.
Phone systems and handsets also need to support VoIP, having identified a provider you will be able to find out if they are compatible or not. If not, you can either upgrade to an IP-enabled on-premise PBX or replace your phone system with a hosted telephony offering.
When to migrate?
We would advise businesses to start thinking about migrating sooner rather than later. Now that ISDN is essentially viewed as a legacy platform, investment in it is likely to fall. This could mean that the standard of the existing network, and support infrastructure, could begin to suffer the effects of being retired well before the 2025 switch off date.
Dates for your diary
2020: Five years before PSTN and ISDN lines will be switched off; businesses will no longer be able to buy any systems that use these networks. Although 2025 may seem a long way off, 2020 is only four years away so if you plan to refresh or upgrade telephony systems within your organisation in the next few years, you should be looking at a VoIP solution instead of upgrading your traditional PSTN or ISDN system.
2025: BT plan to have migrated all existing customers to their IP network. This presents an excellent opportunity for businesses to explore VoIP technology prior to the switch off and find a competitive provider.
* BT own a significant proportion of UK ISDN channels.
Ian Davies, managing director, Liberty-i