Flowire
From Zenitel Wiki
Flowire is based on the HomePlug AV power line communications specification, only using 24 - 48 V DC as the medium. It is a network bridge between Ethernet and a PLC link.
There are two variants
Reset to Factory defaults
Flowire can be reset to Factory defaults by pressing the button for 15 seconds. The recessed button is located next to the Ethernet connector.