ICTS advise:

The phone system is currently experiencing a partial unavailability, which means Dovedale and voice over IP (VoIP) phones are unable to communicate with Ilam analogue phones.

External calls and calls to Ilam VoIP phones are still working at present, as are outgoing calls from Ilam analogue phones to all numbers.

Vendor support has been contacted and we will provide another update as soon as this is resolved.