--> It asks for a number to ring all the phones.
What asked for a number?
Log on to obitalk. In the OBi Dashboard, click on your OBi device. Under "Configure Your Voice Services" you should have "Google Voice Account" and the status should be "Connected".
If that's not the case, you can click on the gear next to the "Google Voice Account" and make sure your username/password are correct.
If that doesn't work, from the OBi Dashboard, your OBi device, click on "OBi Expert Configuration", click "OK" on the popup alert, then click "Enter OBi Expert". From there, click on "System Status" and check the information listed. Is the IP address correct, DNS server(s), etc.