Obi100 and Obi110 Google Voice with Simonics Gateway

Obi100 and Obi 110 devices worked great with Google Voice but Obihai declared these devices to be end of life in August 2016. So a recent Google change made these devices to stop working with GV.
To solve this, you could either buy a newer Obi 200 series device or use a paid GV gateway setup by simonics.

Here are the instructions for using simonics GV gateway from the ObiTalk forum post:

1:  Assumptions:  you have an OBi 100 or 110, running the final build 2886 firmware.  You have a working inbound Google Voice telephone number assigned to your Google account.  You've paid the fee to use the gateway, and you are on the gateway setup page.

2:  Go to your OBiTALK web dashboard:  https://www.obitalk.com/obinet/pg/obhdev.  Click the OBi device.  Find the Service Provider (SP1 or SP2) that was setup to use Google Voice.  Delete the SPx configuration by clicking the trash can icon.

3:  After waiting a few minutes for the OBi's configuration to be remotely deleted, again click on the SP1 or SP2 you want to use.  On the next page, scroll down to the bottom and select "OBiTALK Compatible Service Providers".  On the next page, scroll down and click "Generic Service Provider" and click "Next".

4:  On the next page, fill in your GVGW server name, SIP user ID and SIP password, and click "Save".

5:  Wait for the portal to remotely configure your OBi.  It will reboot once or twice (power LED will blink on then off).  Give it plenty of time to finish.

6:  Refresh the OBiTALK dashboard in your browser, and click the SPx.  You should now see that it is registered to the gatway.  You're done!