If you have assigned a static IP address to your PS3 and set that IP address as the DMZ host you can verify that everything is open on your end through the Playstation 3 internet browser.
If you go to http://canyouseeme.org in the Playstation 3 Internet Browser, you can check all of the necessary ports (80, 443, 3074, 3478, 3479, 3658, and 5223). If you forwarded the ports for your static IP address, then you should see the ports all displaying as open. However, if you took the static IP you assigned and set your Playstation 3 as the DMZ host of your router, they should all show up as "Connection Refused."
Make sure that you do not accidentally have DMZ and port forwarding enabled at the same time (for the same static IP), as these settings cancel each other out and cause this problem.
