Need help playing PS3 games online?

i am using a westell DSL modem from century link. my games work, i can chat with other friends on PSN, i can watch netflix, and browse the internet, but it wont let me play games online. the game i am trying to play is socom confrontation. when i start it it takes a while to initialize network and search for updates. once its started i go to join a game then says network connection lost and logs me out of PSN. everytime i get kicked off it gives me a new error code. i tried everything from switching MTU to 1492 and reseting modem and system but it still doesnt work. any suggestions please. and please dont talk bad about PSN or Socom Confrontation.