The University telephony service has now been restored to full functionality.
The reason for outage was due to two major breaks in the BT lines provided to us by Vodafone. As both our main line and our backup line went down at roughly the same time our resiliency was lost.
We are currently working with Vodafone to create a solution that will provide more resiliency in the future to prevent this issue re-occurring.
Apologies for the inconvenience.