
Everything you need to know:
The Big ISDN Switch Off
The Big Switch Off of the Public Switched Telephone Network (PSTN) and Integrated Services Digital Network (ISDN) is now in motion. As of September 2023, service providers have stopped offering traditional telephone line solutions. By January 2027, the UK's copper network will be fully decommissioned, making way for internet-based voice solutions. This transition means that telephone landlines will be replaced by advanced digital technologies like Microsoft Teams solutions and SIP Trunking. Who will be most impacted by this change, and how can you prepare for the future? Let’s delve into the details and ensure you’re ready for the Big Switch Off.

What is ISDN/PSTN?
Integrated Services Digital Network (ISDN) and Public Switch Telephone Network (PSTN) are both traditional phone line solutions that will be shut off as part of the UK’s Big Switch Off in 2027. Businesses using either communication method will need to switch to VoIP solutions before the year end.
PSTN is a traditional analogue communication method leveraging copper wires to transfer speech signals, while ISDN is a digital communication system (allowing for faster data transfer rates) which also uses telephone lines. Both solutions will need to be replaced by alternative voice communications through the internet.
Benefits of Pen Testing
Real World Simulation
Simulates a cyberattack to assess your security measures.
Compliance with Regulations
Maintains compliance to avoid legal and financial consequences.
Risk Prioritisation
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Prioritises vulnerabilities by degree of risk, addressing critical issues first.
Customer Data Protection
Addresses vulnerabilities that lead to breaches, identify theft or unauthorised access.
Vulnerability Identification
Exposes security vulnerabilities to reveal potential entry points.
Proactive Offense
Proactively reduces attack vectors through regular assessments.









Comprehensive Security Assessment
Evaluates current security controls to ensure systems can withstand cyberthreats.
Threat Defense
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Identifies vulnerabilities missed by traditional security measures.
Risk Mitigation
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Enables effective prioritisation and mitigation of potential cyber-risks.
