Can't get Vonage Extension to work over wifi for my Samsung Fascinate phone

Who is your ISP and what is the model of the modem?

My ISP i Verizon Fios and it's an Actiontec MI424WR rev 1

That Actiontec is another router and you also need to configure it.  If you plug a PC directly into it, http://192.168.1.1 will access its web interface with admin and password as the default login.
If you don't have a second router, set QOS to point to the Samsung.
Do you have a 2nd router?

I already got into it and opened up sip and rtp ports except for 2 ports used by Skype. I also minimized the firewall. What else is necessary?

QOS is Quality Of Service which prioritizes traffic to the device.  Did you turn it on?  And/or, putting my MagicJack in the DMZ made it work a lot better!
Did you do everything it says to for setting it up? https://support.vonage.com/app/answers/detail/a_id/2705

I did all the things at the link you posted.

When I tried to do DMZ the router complained that that would render my port forwarding useless.

Do you think that QOS could be the whole difference?

If a device is in the DMZ, it doesn't need port forwarding; it exists outside the firewall and NAT.  If it doesn't work in the DMZ, the problem is in your phone (period).
QOS sets traffic as a higher priority so it takes precedence over other packets.

I contacted Vonage advanced support and they didn't have any new ideas. I spoke to a voip expert and he said it sounded like a firewall problem.

I have Avast security on the phone and I contacted Avast and they said the uninstall Avast to see if it's blocking. It's unlinkely because they say that the firewall is only on a rooted phone and my phone isn't rooted.

I would like to try my phone on another network. I may also try to use Wireshark to check the packets and see where they get blocked.

I unistalled Avast and that didn't help. I need to get to another wifi setup to see if that makes a difference

Here are the uPNP items


    Universal Plug and Play provides the ability for the router to have new UPnP supported devices connected without having to reconfigure or reboot the router


      Allow Other Network Users to Control Wireless Broadband Router's Network Features
      Enable Automatic Cleanup of Old Unused UPnP Services

There are checkboxes next to the above 2 items.

There is also a drop down for publish only the main wan connection or publish all wan connections.

I assume that I should check the top 2 items. What should I do about the wan connections choice?

Publish all wan connections

I set the uPNP and opened the DMZ but it didn't work.

You should not have needed to do both.  uPNP should have caused Vonage to be able to open any needed ports or putting your phone in the DMZ places it outside the routers firewall so that every port is open.  Does the Actiontec have a "guest" network and are you connected to it?  If so, uPNP would be disabled and I suspect you couldn't put the phone in the DMZ, either.

I'll try the uPNP alone but I have spoken to high level techs of Vonage and they sort of admitted that calls over WiFi don't work

I tried just jPNP and it didn't work. At this point I feel that it doesn't work as the advanced techs at Vonage hinted in their statements.

I've come to the conclusion that it really doesn't work with WiFi. Thanks for your suggestions.