Site linked by billsimon.
http://www.obitalk.com/forum/index.php?topic=3119.msg24817#msg24817
I suspect many OBi users will be complaining today as the Google Talk service seems to be down. This is probably a good site to check once in a while to see the status of the Google Talk service.
http://www.google.com/appsstatus#hl=en&v=status&ts=1343361599000
I got my phone up and working by changing my setting in my Google Voice account. These are the steps that I followed:
My OBi Does Not Ring
Possible causes for this are:
• In www.google.com/voice (Voice settings), "Forwards to: Google Chat" is not checked. See here for more.
• You are using the 'Talkatone' or 'GrooVe IP' app on your Apple or Android smart phone device. When the app is running, it interferes with the OBi device's ability to receive calls. To receive calls on the OBi, the app MUST be removed from your smart phone.
• The caller is using a phone that was used to authenticate this OBi device's Google Voice account. The symptom is the caller will always go to Google Voice voicemail and never ring the OBi's phone. The solution is:
1. Go to Google Voice voice settings. The Voice settings
selection is available from the top-right corner "gear" icon.
2. From the "Phones" tab, select "Edit" on the phone from
which you are calling.
3. Select "Show advanced settings."
4. Select "No" for "Voicemail Access."
5. Select "Save" at the bottom of the page.