Welltech LP-389 v.1.06 Operation Guide - Manual (Page 11)

11
Connecting the phone
Fig. 1
Fig. 2
Next plug the Ethernet (network) cable into the RJ45 connector labeled LAN,
and plug the other end into the network side to establish a data link. The
second RJ45 connector, labeled PC, is for daisy-chaining further Ethernet
devices (switch inside).
If you are using an external power supply, please insert the plug of the
power supply into the connector labeled next to the LAN port.
If you want to use a headset, it can be connected to the audio jack (3.5 mm)
on the left hand side of the LP389.