Note that factory resetting your phone will permanently erase any and all settings and could render the phone inoperable. Therefore, only perform this procedure if advised by your IPFINITY support representative.
Usually this step is a precursor to reloading the base configuration settings (aka pre-provisioning) in the phone as described here.
For Grandstream GXP2100, GXP 2110, GXP2120, GXP2124, GXP1405, GXP1400, GXP1450, please follow the instructions below:
From the phone's keypad, navigate to Menu > Config > Factory Reset. Confirm that you want to factory reset and press OK.
The Factory Reset takes a while; please do not interrupt the process.
Once the reset has taken effect, you may be required to load the base configuration into the phone. If so, please refer to the Grandstream pre-provisioning article here.