Telephony replacement

Why is the University's telephony service being replaced?

The University's existing telephony service (Chorus) is made up of two types of telephone lines:

  • approximately 1,000 analogue and critical lines in 80 of the departments and 40 of the colleges/PPHs 
  • approximately 17,000 digital telephone lines 

The reasons for replacing this service are:

  • BT announced plans to switch off all analogue telephone services, which are used by the University's critical and analogue lines, in December 2025. While this has been extended for vulnerable household customers until January 2027, businesses are being urged to convert to digital alternatives before December 2025. Therefore, the University needs to respond promptly to meet this deadline and migrate our critical and analogue lines to the University’s chosen alternative solution
  • the Chorus service is provided by Atos (which was bought by Mitel in 2023).  The current supplier contract is due to end in July 2026 and the University is taking this opportunity to assess suppliers 
  • manufacturer support (provided by Atos/Mitel) for the 17,000 Unify telephone handsets (desk phones) in use across the collegiate University ended in July 2023.  The handsets are currently considered to be a low security risk because they are not connected to the internet so we can continue to use them until a new supplier system is in place. However, the supplier (or suppliers) of telephony services needs to be chosen before the third-party support for the platform ends in July 2026 

How is the telephony replacement being managed?

The Telephony Replacement project will manage the transition to a new telephony service.  This might be delivered by more than one supplier.   The project is being managed in two phases and further detail is available from the dedicated webpages for each:

  1. Phase 1: replacement of analogue and critical lines
  2. Phase 2: replacement of digital lines (VOIP telephony)

What are analogue, critical and digital (VOIP) telephone lines?

  • critical lines are telephone lines that serve critical services, such as lift phones, alarm lines, and backup lines for college lodges. They can be used for inbound and outbound phone calls and will continue to work in the event of power outages or disruption to the Chorus phone system.  They use dedicated copper wiring and network infrastructure, and have a Service Level Agreement (SLA) which means that outages should be responded to by our suppliers within 4 hours 
  • analogue lines are like critical lines and use the same network infrastructure. The difference is that they usually provide telephony to places that 'VOIP' (Voice Over Internet Protocol) telephony couldn't easily reach at the time of installation, and that the service is not critical to life or business operations  
  • VOIP telephony is another term for digital phone lines.  Your Chorus desk phone uses VOIP telephony so is a digital line