The firewall may be blocking the Ooma VPN.
Try connecting the Ooma device directly behind the modem. The network cable routed from the modem connects to the Internet port of the Ooma device. A network cable from the Ooma device's Home port connects to the firewall, etc.
A phone is connected to the phone port of the Ooma device.
Reboot the Modem, than when the modem is done booting, reboot the Ooma device, than when the Ooma device comes up, reboot the firewall.
The first time the Ooma device comes up, it may take upwards to an hour to download the latest fireware.
You haven't said that you have a router, just a firewall? If you have a firewall/router make connections as per your first post. Connect nothing to the Ooma Home port.
But if you don't have a router, the output of the Ooma Telo Home port is like a router and will issue individual IP addresses. In that case, the hook up that I would use, if you don't have a router, is to place the Ooma device behind the firewall (Firewall output to Ooma Telo Internet port). Than connect the Switch to the Ooma Telo's home port. The Ooma Telo will than issue IP addresses for any thing that you connect to the Switch. Modem-Firewall-Ooma-Swtich
Something else I would do:
a. Access your Ooma Telo “home port” by plugging in a patch (network) cable from the Ooma Telo home port to a computer’s network card port. Sometimes you have to restart your computer after installing the patch cable, so that a proper connection occurs.
b. Type http://setup.ooma.com in you browser address window and hit enter. The “Ooma Setup” window opens.
c. In the left hand Navigation window, select “Network”.
d. Under “Modem Port MAC Address”, select Use Built in:
e. Select the “Update button”.
f. Do a “cold boot” of the modem.
g. Than do a "cold boot” of the Firewall.
h. Than do a “cold boot” of the Ooma device.