If you want to troubleshoot this, then the first thing that needs to be determined is whether the problem is with your Google Voice phone number or settings, or the problem is with your OBi and the telephone.
Here are the steps:
Log into your OBiTALK dashboard:
http://www.obitalk.com/obinet/pg/obhdevClick the SPx that corresponds to your Google Voice Service Provider configuration. Click the "Accept" button after reading the warning. Look at the "Active Google Username:" field, and make note of which Google account you are using. Is it correct?
Unplug your OBi from power.
Log into Google Voice, using the same user ID as you saw on the OBiTalk portal. Go to the Phones settings tab:
https://www.google.com/voice#phonesLook at the left side of the page. Do you see the exact two words "Your number", and not "Access number" or "Get a Voice number"? Only the first phrase indicates a full-function GV account with its own, inbound number.
Confirm that you have "Google Chat" listed as a forwarding destination, and that you have a check mark to the left of it.
Click the "edit" button, and on the next screen, confirm that you don't have a calling schedule set up which would cause calls to go to voicemail instead of ringing.
Log into Gmail, again, using the same user ID and password. Look at your chat avatar on the left side of the page, and click it. A settings box should pop up. Does it say "Try the new Hangouts"? If so, do not click that link. Or, does it say "Revert to old Chat"? If so, do click that link. You should now be using Chat vs. Hangouts. Make an outbound call from your computer. Does it work?
Have somebody call your GV phone number, ("Your number", above). Does it ring your computer? If so, answer the call and test that it works. If not, look in the History section. Does the call log appear there?