Please find your device by the picture. Once located you will need to know if you are connecting to a Standard Modem or a Modem/Router Combo, you can find those here:
Modem \ Router Combination
If your device is a Zyxel or SmartRg make sure to plug your phone directly into Phone 1 or VOIP 1.
Cisco Spa 122
From Bottom to Top Power On/Solid, Globe On/Flashing, Phone 1 ON/Flashing if on active call, Phone 2 ON if they a second line/Flashing if on active call