I did reach out to Obihai, and got this response from them:
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This device is out of warranty and does not have an Extended Support on it.
To continue using Google Voice with the OBi, you will need to purchase a
Support contract to enable firmware upgrades.
To purchase it, please log into your
OBitalk.com account and click on your
dashboard.
Further click on your device, and go to Support and Warranty tab.
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It's not very clear if you require Extended Support to enable firmware upgrade only, or is it required for GoogleVoice service as well. I have another Obi202 device which is out of warranty, and I was able to upgrade firmware w/ the expired support contract.
What is the latest firmware for Obi100 (I thought the latest firmware was released in 2014) - my unit doesn't have a "warning sign" telling me that newer firmware is available, so I think I'm running the latest. How do I confirm?