The PSTN and ISDN Switch-Off Explained
The PSTN, a long-standing telephony infrastructure that has served as the backbone of traditional landline communications, will close its doors in 2025. With the PSTN switch-off, every phone line in the UK will transition to a fully digital network, utilising Voice over Internet Protocol (VoIP) technology across fibre-based services. Alongside PSTN, the ISDN, which has been a critical part of voice services like ISDN2/30, will also cease operation.
