I had a problem with the firewall with Verizon Fios. My Ooma telo wouldn't work, since it was getting blocked. Nothing on the telo would light up except for the 1 and the 2.
You need to log into http://192.168.1.1
- this will allow you to get to the firewall page. However, you don't want to disable or even change the firewall for everything. What happens is that your computer might be 192.168.1.3, while a web-enabled Blu-Ray player might be 192.168.1.2, etc. Basically, every item that you have hooked up to your integrated modem/router from Verizon will have a unique number like that. One of those should be your Ooma device - it might be 192.168.1.7, for instance.
You want to establish that the Ooma device is allowed into the DMZ host. Basically you are turning off the firewall for the Ooma device only, while keeping security settings for everything else. I would have someone at Verizon tech support help you out to make sure that you're doing this right.
By the way, Ooma discusses the problem if you search under Service Ports. They don't mention Fios specifically, but they discuss the firewall problem.