You can reset the SPA3102 to factory default using the Interactive Voice Response (IVR) and following these steps:

1. Plug an analog (PSTN) phone into the Phone 1 port
2. Dial ****: you'll hear a voice prompt.
3. When the IVR is done talking, enter the sequence 73738, followed by a #.
4. Press 1 to confirm. The unit will reboot to factory defaults.