I re-read your original post. The
Offline status shown on the OBiTALK web portal doesn't refer to Google Voice, even though it is displayed to the right of SP1. It means that the OBiTALK back-end isn't getting a response from your device, as if it has been unplugged from power or from your Ethernet connection.
You may want to email
support@obihai.com to ask them to look at their OBiTALK server logs or otherwise work with you to diagnose the failure, if it's not being caused by your internet connection.