I have a DSL modem at my house and have never had a problem with DNAS. However, I tried playing Socom II at my Dad's house (he has cable) and I am getting the same message. It says my connection is fine but for whatever reason I just can't play.
I was about to post something like this until I saw the thread. I have found some links that might help you. I guess there is a problem with wireless routers and DNAS. I have no clue what mine is... Anyway here are the links:
https://www.hostultra.com/~topper/dnasfaq.html
https://www.scea.com/Content/peripher...o/default.html
https://boardsus.playstation.com/play...workAdaptorFAQ