"Zultys is a fully IP-based system with SIP so if it disappeared I can move to something else," he said, adding all the other products he looked at were not SIP-based.

"They are worth keeping alive. Zultys has given me so much more power over my phone network that the old Nortel PABX."

Millard also praised the integration partner Centrix, describing the people as the most thorough he has dealt with.